6560-50-P
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 82
[EPA-HQ-OAR-2023-0043; FRL-10125-02-OAR]
RIN 2060-AV77
Protection of Stratospheric Ozone: Listing of Substitutes under the Significant New
Alternatives Policy Program in Commercial and Industrial Refrigeration
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
SUMMARY: Pursuant to the U.S. Environmental Protection Agency’s Significant New
Alternatives Policy program, this action lists several substitutes as acceptable, subject to
use conditions, for retail food refrigeration, commercial ice machines, industrial process
refrigeration, cold storage warehouses, and ice skating rinks. Through this action, EPA is
incorporating by reference standards which establish requirements for commercial
refrigerating appliances and commercial ice machines, safe use of flammable refrigerants,
and safe design, construction, installation, and operation of refrigeration systems. This
action also exempts propane, in the refrigerated food processing and dispensing end-use,
from the prohibition under the Clean Air Act (CAA) on knowingly venting, releasing, or
disposing of substitute refrigerants in the course of maintaining, servicing, repairing or
disposing of an appliance or industrial process refrigeration, as the Administrator is
determining, on the basis of existing evidence, that such venting, release, or disposal of
this substance in this end-use does not pose a threat to the environment.
DATES: This rule is effective [INSERT DATE 30 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER]. The incorporation by reference of
certain material listed in the rule is approved by the Director of the Federal Register as of
[INSERT DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL

REGISTER]. The incorporation by reference of certain other material listed in the rule
was approved by the Director of the Federal Register as of February 21, 2012 (76 FR
78832), May 11, 2015 (79 FR 19454), and January 3, 2017 (81 FR 86778).
ADDRESSES: EPA has established a docket for this action under Docket ID No. EPAHQ-OAR-2023-0043. All documents in the docket are listed on the
https://www.regulations.gov website. Although listed in the index, some information is
not publicly available, e.g., Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. Certain other material, such as copyrighted
material, is not placed on the Internet and will be publicly available only in hard copy
form. Publicly available docket materials are available electronically through
https://www.regulations.gov or in hard copy at the Air and Radiation Docket, EPA/DC,
EPA West, Room 3334, 1301 Constitution Avenue, NW, Washington, DC 20460. The
Docket Center’s hours of operations are 8:30 a.m.–4:30 p.m., Monday–Friday (except
Federal Holidays). For further information on EPA Docket Center services and the
current status, please visit https://www.epa.gov/dockets.
FOR FURTHER INFORMATION CONTACT: Perrin Krisko, Stratospheric
Protection Division, Office of Atmospheric Protection (Mail Code 6205A),
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, DC
20460; telephone number: 202-564-2328; email address: krisko.claudia@epa.gov.
Notices and rulemakings under EPA’s Significant New Alternatives Policy (SNAP)
program are available on EPA’s SNAP website at https://www.epa.gov/snap/snapregulations.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. General information
A. Executive summary and background
B. Does this action apply to me?

C. What acronyms and abbreviations are used in the preamble?
II. What is EPA finalizing in this action?
A. Retail Food Refrigeration—Listing of HFO-1234yf, HFO-1234ze(E), R454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions,
for use in new stand-alone units, remote condensing units, supermarket
systems, and refrigerated food processing and dispensing equipment and
listing of R-454A as acceptable, subject to use conditions, for use in new
remote condensing units and supermarket systems
1. Background on retail food refrigeration
2. What are the ASHRAE classifications for refrigerant flammability?
3. What are HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A,
R-457A, and R-516A and how do they compare to other refrigerants in
the same end-use?
4. Why is EPA finalizing these specific use conditions?
5. What additional information is EPA including in these listings?
6. How is EPA responding to comments on retail food refrigeration?
B. Retail Food Refrigeration—Listing R-290 as acceptable, subject to use
conditions, for use in new refrigerated food processing and dispensing
equipment and revision of the use conditions provided in the previous listings
of R-290 as acceptable, subject to use conditions, for use in new stand-alone
units
1. Background on retail food refrigeration
2. What are the ASHRAE classifications for refrigerant flammability?
3. What is R-290 and how does it compare to other refrigerants in the
refrigerated food processing and dispensing equipment end-use
category?
4. Why is EPA finalizing these specific use conditions for refrigerated
food processing and dispensing equipment?
5. How does the listing for R-290 in refrigerated food processing and
dispensing equipment relate to regulations implementing the venting
prohibition under CAA section 608?
6. What existing use conditions apply to this refrigerant in the standalone units end-use category?
7. What updates to existing use conditions for stand-alone units is EPA
finalizing?
8. How do the new use conditions for R-290 in stand-alone units differ
from the existing ones and why is EPA changing the use conditions?
9. What additional information is EPA including in these listings?
10. How is EPA responding to comments on listing R-290 in refrigerated
food processing and dispensing equipment and updating the use
conditions for R-290 in stand-alone units?
C. Commercial Ice Machines—Listing of HFC-32, HFO-1234yf, R-454A, R454B, R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use
conditions, for use in new commercial ice machines
1. Background on commercial ice machines
2. What are the ASHRAE classifications for refrigerant flammability?
3. What are HFC-32, HFO-1234yf, R-454A, R-454B, R-454C, R-455A,
R-457A, and R-516A and how do they compare to other refrigerants in
the same end-use?
4. Why is EPA finalizing these specific use conditions?
5. What additional information is EPA including in these listings?
6. How is EPA responding to comments on commercial ice machines?

D. Commercial Ice Machines—Revision of the use conditions in the previous
listing of R-290 as acceptable, subject to use conditions, for use in new selfcontained commercial ice machines
1. Background on commercial ice machines
2. What are the ASHRAE classifications for refrigerant flammability?
3. What is R-290 and where is there information on its use in this enduse?
4. What existing use conditions apply to this refrigerant in this end-use?
5. What updates to existing use conditions for commercial ice machines
is EPA finalizing?
6. How do the new use conditions for commercial ice machines differ
from the existing ones and why is EPA changing the use conditions?
7. What additional information is EPA including in this listing?
8. How is EPA responding to comments on listing R-290 and updating
the use conditions for R-290 in self-contained commercial ice
machines?
E. Industrial Process Refrigeration—Listing of HFC-32, HFO-1234yf, HFO1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A as
acceptable, subject to use conditions, for use in new industrial process
refrigeration
1. Background on industrial process refrigeration
2. What are the ASHRAE classifications for refrigerant flammability?
3. What are HFC-32, HFO-1234yf, HFO-1234ze(E), R-454A, R-454B,
R-454C, R-455A, R-457A, and R-516A and how do they compare to
other refrigerants in the same end-use?
4. Why is EPA finalizing these specific use conditions?
5. What additional information is EPA including in these listings?
6. How is EPA responding to comments on industrial process
refrigeration?
F. Cold Storage Warehouses—Listing of HFO-1234yf, HFO-1234ze(E), R454A, R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use
conditions, for use in new cold storage warehouses
1. Background on cold storage warehouses
2. What are the ASHRAE classifications for refrigerant flammability?
3. What are HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A,
R-457A, and R-516A and how do they compare to other refrigerants in
the same end-use?
4. Why is EPA finalizing these specific use conditions?
5. What additional information is EPA including in these listings?
6. How is EPA responding to comments on cold storage warehouses?
G. Ice Skating Rinks—Listing of HFO-1234yf, HFO-1234ze(E), R-454C, R455A, R-457A, and R-516A as acceptable, subject to use conditions, for use
in new ice skating rinks with a remote compressor
1. Background on ice skating rinks
2. What are the ASHRAE classifications for refrigerant flammability?
3. What are HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A,
and R-516A and how do they compare to other refrigerants in the same
end-use?
4. Why is EPA finalizing these specific use conditions?
5. What additional information is EPA including in these listings?
6. How is EPA responding to comments on ice skating rinks?
H. Use conditions and further information for retail food refrigeration,

commercial ice machines, industrial process refrigeration, cold storage
warehouses, and ice skating rinks with a remote compressor
1. What use conditions is EPA finalizing and why?
2. What additional information is EPA including in these listings?
3. How is EPA responding to comments on use conditions?
I. Exemption for R-290 from the venting prohibition under CAA section 608 for
refrigerated food processing and dispensing equipment
1. What is EPA’s final determination regarding whether venting,
releasing, or disposing of R-290 in refrigerated food processing and
dispensing equipment would pose a threat to the environment?
2. What is EPA’s final determination regarding whether venting of R-290
from refrigerated food processing and dispensing equipment is
exempted from the venting prohibition under CAA section 608(c)(2)?
3. When will the exemption from the venting prohibition apply?
4. What is the relationship between this exemption under CAA section
608(c)(2) and other EPA rules?
5. How is EPA responding to comments on the exemption for R-290
from the venting prohibition?
J. How is EPA responding to other comments?
III. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 14094: Modernizing Regulatory Review
B. Paperwork Reduction Act (PRA)
C. Regulatory Flexibility Act (RFA)
D. Unfunded Mandates Reform Act (UMRA)
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination with Indian Tribal
Governments
G. Executive Order 13045: Protection of Children from Environmental Health
and Safety Risks
H. Executive Order 13211: Actions that Significantly Affect Energy Supply,
Distribution, or Use
I. National Technology Transfer and Advancement Act and Incorporation by
Reference
J. Executive Order 12898: Federal Actions to Address Environmental Justice in
Minority Populations and Low-Income Populations and Executive Order
14096: Revitalizing Our Nation’s Commitment to Environmental Justice for
All
K. Congressional Review Act
IV. References
I. General information
A. Executive summary and background
EPA is finalizing new and revised listings after its evaluation of human health and
environmental information for these substitutes under the Significant New Alternatives
Policy (SNAP) program. The Agency is finalizing action on new and revised listings in
the refrigeration and air conditioning (AC) sector based on the information that EPA has

included in the docket. This final action provides new refrigerant options, thereby
increasing flexibility for industry, in specific uses.
This action lists new alternatives for the refrigeration and AC sector. Specifically,
EPA is:
•

Listing hydrofluoroolefin (HFO)-1234yf, HFO-1234ze(E), R-454C, R-455A,
R-457A, and R-516A as acceptable, subject to use conditions, for use in new
retail food refrigeration equipment (i.e., stand-alone units, remote condensing
units, supermarket systems, and refrigerated food processing and dispensing
equipment);

•

Listing R-454A as acceptable, subject to use conditions, for use in new remote
condensing units and supermarket systems;

•

Listing R-290 (propane) as acceptable, subject to use conditions, for use in
new refrigerated food processing and dispensing equipment and revising the
existing use conditions for R-290 in new stand-alone units.

•

Listing HFO-1234yf, R-454C, R-455A, R-457A, and R-516A as acceptable,
subject to use conditions, for use in new commercial ice machines;

•

Listing hydrofluorocarbon (HFC)-32, R-454A, and R-454B as acceptable,
subject to use conditions, for use in new commercial ice machines with a
remote compressor, for batch-type self-contained automatic commercial ice
machines with a harvest rate above 1,000 lb ice per 24 hours, and for
continuous type self-contained automatic commercial ice machines with a
harvest rate above 1,200 lb ice per 24 hours;

•

Revising the existing use conditions for R-290 for use in new self-contained
commercial ice machines;

•

Listing HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R516A as acceptable, subject to use conditions, for use in new equipment for

industrial process refrigeration (IPR), including chillers and direct expansion
IPR equipment;
•

Listing HFC-32, R-454A, and R-454B as acceptable, subject to use
conditions, for use in new equipment for IPR, including chillers and direct
expansion IPR equipment where the temperature of the refrigerant entering
the evaporator is less than or equal to -30 °C (-22 °F);

•

Listing HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A,
and R-516A as acceptable, subject to use conditions, for use in new cold
storage warehouses; and

•

Listing HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R516A as acceptable, subject to use conditions, for use in new ice skating rinks
with a remote compressor.

In general, the final use conditions are consistent across the various substitutes
and end-uses contained in this final rule. Because of this similarity, EPA discusses the
final use conditions that apply to retail food refrigeration, commercial ice machines,
industrial process refrigeration, cold storage warehouses, and ice skating rinks in section
II.H of this preamble. In summary, the common use conditions are:
1) These refrigerants may be used only in new equipment, designed specifically
and clearly identified for use with the refrigerant. None of these listings provide for use
of the substitutes in a conversion or “retrofit” refrigerant for existing equipment.
2) These refrigerants may be used in equipment that a) is consistent with the
requirements listed in the 2nd edition (dated October 27, 2021) of UL1 Standard 60335-289, “Household and Similar Electrical Appliances - Safety - Part 2-89: Requirements for
Commercial Refrigerating Appliances and Ice-Makers with an Incorporated or Remote
Refrigerant Unit or Motor-Compressor” (hereafter “UL 60335-2-89,” which refers to the
UL, formerly known as Underwriters Laboratories.

2nd edition of UL 60335-2-89 unless otherwise stated), and b) is installed consistent with
the requirements of ASHRAE 15-2022, “Safety Standard for Refrigerating Systems.” For
equipment outside the scope of UL 60335-2-89, as described later in this document, or
that is located in industrial occupancies as defined in ASHRAE 15-2022, refrigerants
listed herein must be used in equipment that is installed in a manner consistent with
ASHRAE 15-2022. For R-290, which already has listings that incorporate by reference
earlier UL standards, EPA is providing a transition period when equipment may meet
either the earlier UL standard or UL 60335-2-89. Stand-alone units or self-contained
commercial ice machines using R-290 that are unchanged, except for cosmetic changes,
from the model or design that was previously certified to the UL 471 (10th edition) or UL
563 standard (8th edition) may continue to be manufactured consistent with those
standards.
3) These refrigerants must be used with warning labels on the equipment and
packaging that are similar to or match verbatim those required by UL 60335-2-89.2
4) Equipment must be marked with distinguishing red color-coded hoses and
piping to indicate use of a flammable refrigerant and marked service ports, pipes, hoses,
and other devices through which the refrigerant is serviced.
5) Equipment must be marked with one or more flammability warning symbols—
either that in Clause 7.6DV D1 of UL 60335-2-89, 2nd edition; that in Annex 1 to
Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9th
edition, for hazard category 1 flammable gases; or marked with both symbols.
Additional use conditions specific to particular end-uses may also apply and are
discussed with each final listing. The regulatory text of the final listings, including the
final use conditions and further information, appears in tables at the end of this document.

2 Or for equipment using R-290 following the requirements of UL 471 or UL 563, they must use the

warning labels required in those listings, which match those required by those standards.

The final listings will appear in appendix Y to 40 Code of Federal Regulations (CFR)
part 82, subpart G. The final revised listings for R-290 in new retail food refrigeration
equipment (stand-alone units only) and in new self-contained commercial ice machines
will appear, respectively, in appendices R and V to 40 CFR part 82, subpart G.
There may be other legal obligations pertaining to the manufacture, use, handling,
and disposal of the listed substitutes that are not included in the information in the tables
(e.g., the CAA section 608(c)(2) venting prohibition or U.S. Department of
Transportation (DOT) requirements for transport of flammable gases). Flammable
refrigerants being recovered or otherwise disposed of from commercial or industrial
refrigeration equipment are likely to be hazardous waste under the Resource
Conservation and Recovery Act (RCRA) (see 40 CFR parts 260 through 270). In
addition, EPA issued a final Technology Transitions Rule under subsection (i) of the
American Innovation and Manufacturing Act of 2020 (hereafter referred to as “the AIM
Act”) (88 FR 73098; October 24, 2023;). Under that rule, EPA restricts the use of many
HFC refrigerants in a variety of subsectors within the Refrigeration, Air Conditioning,
and Heat Pumps sector, including in technologies covered by this final SNAP rule.3
Throughout this document, EPA notes relevant restrictions on refrigerants under the final
Technology Transitions Rule. In finalizing the listing decisions in this rulemaking, EPA
is cognizant of the restrictions established under the Technology Transitions Rule. This is
because the listings in this SNAP rule are generally intended to expand the universe of
available options in certain end-uses. EPA recognizes that there could be situations where
there would be little practical value in listing alternatives acceptable under SNAP that
cannot legally be used in a particular end-use due to restrictions under Technology
Transitions Rule, and this consideration could be particularly pronounced with respect to

3 End-uses under SNAP are included in the similar concept of subsectors defined in the Technology

Transitions Rule (88 FR 73098, October 24, 2023).

those alternatives that would be subject to restrictions under the Technology Transitions
Rule in the near future (e.g., as of January 1, 2025). However, the SNAP and Technology
Transitions programs are established under different legal authorities and use separate
frameworks for making decisions. Substitutes that are listed as acceptable, acceptable
subject to use conditions, acceptable subject to narrowed use limits, or unacceptable
under the SNAP program are evaluated through a comparative risk framework that
considers the overall risk posed to human health and the environment for specific enduses. In evaluating the substitutes listed in this rule, EPA has considered whether they
present risks that are lower than or comparable to risks from other substitutes that are
currently or potentially available in the end-uses under consideration, consistent with its
approach under SNAP.
In addition, EPA is exempting R-290 used in the refrigerated food processing and
dispensing end-use from the prohibition under CAA section 608(c)(2) on knowingly
venting, releasing, or disposing of substitute refrigerants in the course of maintaining,
servicing, repairing or disposing of an appliance or industrial process refrigeration, as the
Administrator is determining, on the basis of current evidence described later in this
preamble, that such venting, release, or disposal of this substance in this end-use does not
pose a threat to the environment. This exemption is being finalized in the regulations
under CAA section 608 at 40 CFR 82.154(a)(1), which addresses the statutory
prohibition and exemptions from it.
SNAP program background
The SNAP program implements CAA section 612. Several major provisions of
section 612 are:
1. Rulemaking
Section 612(c) requires EPA to promulgate rules making it unlawful to replace
any class I (chlorofluorocarbon (CFC), halon, carbon tetrachloride, methyl chloroform,

methyl bromide, hydrobromofluorocarbon, and chlorobromomethane) or class II
(hydrochlorofluorocarbon (HCFC)) ozone-depleting substance (ODS) with any substitute
that the Administrator determines may present adverse effects to human health or the
environment where the Administrator has identified an alternative that: 1) Reduces the
overall risk to human health and the environment and 2) is currently or potentially
available.
2. Listing of Unacceptable/Acceptable Substitutes
Section 612(c) requires EPA to publish a list of the substitutes that it finds to be
unacceptable for specific uses and to publish a corresponding list of acceptable
substitutes for specific uses.
3. Petition Process
Section 612(d) grants the right to any person to petition EPA to add a substance
to, or delete a substance from, the lists published in accordance with section 612(c).
4. 90-Day Notification
Section 612(e) directs EPA to require any person who produces a chemical
substitute for a class I substance to notify the Agency not less than 90 days before a new
or existing chemical is introduced into interstate commerce for significant new use as a
substitute for a class I substance. The producer must also provide the Agency with the
producer’s published or unpublished health and safety studies on such substitutes.
The regulations for the SNAP program are promulgated at 40 CFR part 82,
subpart G, and the Agency’s process for reviewing SNAP submissions is described in
regulations at 40 CFR 82.180. Under these rules, the Agency has identified five types of
listing decisions: acceptable; acceptable subject to use conditions; acceptable subject to
narrowed use limits; unacceptable; and pending (40 CFR 82.180(b)). Use conditions and
narrowed use limits are both considered “use restrictions.” Substitutes that are deemed
acceptable with no use restrictions (no use conditions or narrowed use limits) can be used

for all applications within the relevant end-uses in the sector. After reviewing a
substitute, the Agency may determine that a substitute is acceptable only if certain
conditions in the way that the substitute is used are met to minimize risks to human health
and the environment. EPA describes such substitutes as “acceptable subject to use
conditions” (40 CFR 82.180(b)(2)). For some substitutes, the Agency may permit a
narrowed range of use within an end-use or sector. For example, the Agency may limit
the use of a substitute to certain end-uses or specific applications within an industry
sector. EPA describes these substitutes as “acceptable subject to narrowed use limits.”
Under the narrowed use limit, users intending to adopt these substitutes “must ascertain
that other alternatives are not technically feasible” (40 CFR 82.180(b)(3)).
In making decisions regarding whether a substitute is acceptable or unacceptable,
and whether substitutes present risks that are lower than or comparable to risks from
other substitutes that are currently or potentially available in the end-uses under
consideration, EPA examines the following criteria in 40 CFR 82.180(a)(7): (i)
atmospheric effects and related health and environmental impacts; (ii) general population
risks from ambient exposure to compounds with direct toxicity and to increased groundlevel ozone; (iii) ecosystem risks; (iv) occupational risks; (v) consumer risks; (vi)
flammability; and (vii) cost and availability of the substitute.
Many SNAP listings include “comments” or “further information” to provide
additional information on substitutes. Since this additional information is not part of the
regulatory decision under SNAP, these statements are not binding for use of the substitute
under the SNAP program. However, statutory and regulatory requirements so listed are
binding under other authorities (e.g., worker protection regulations promulgated by the
U.S. Occupational Safety and Health Administration (OSHA)). The “further information”
classification does not necessarily include all other legal obligations pertaining to the use
of the substitute. While the items listed are not legally binding under the SNAP program,

EPA encourages users of substitutes to apply all statements in the “Further Information”
column in their use of these substitutes. In many instances, the information simply refers
to sound operating practices that have already been identified in existing industry and/or
building codes or standards. Thus, many of the statements, if adopted, would not require
the affected user to make significant changes in existing operating practices.
For additional information on the SNAP program, visit the SNAP website at
https://www.epa.gov/snap. The full lists of acceptable substitutes for ODS in all industrial
sectors are available at https://www.epa.gov/snap/snap-substitutes-sector. For more
information on the Agency’s process for administering the SNAP program or criteria for
evaluation of substitutes, refer to the initial SNAP rule published March 18, 1994 (59 FR
13044), codified at 40 CFR part 82, subpart G. SNAP decisions and the appropriate
Federal Register citations can be found at https://www.epa.gov/snap/snap-regulations.
Substitutes listed as unacceptable; acceptable, subject to narrowed use limits; or
acceptable, subject to use conditions, are also listed in the appendices to 40 CFR part 82,
subpart G.
Background on requirements concerning venting, release, or disposal of ODS and
substitute refrigerants under CAA section 608
The statutory requirements concerning venting, release, or disposal of ODS
refrigerants and substitutes for ODS used as refrigerants are under CAA section 608, and
EPA’s authority to promulgate the regulatory revisions in this action is based in part on
CAA section 608. Section 608 of the Act, as amended, titled National Recycling and
Emission Reduction Program, requires, among other things, that EPA establish
regulations governing the use and disposal of ODS used as refrigerants, such as certain
CFCs and HCFCs, during the service, repair, or disposal of appliances and IPR.4 Section

Additional information about the 608 Refrigerant Management Program is available in EPA’s rules
implementing that program, such as rules published on May 14, 1993 (58 FR 28660), November 18, 2016
(81 FR 82272), and March 11, 2020 (85 FR 14150).
608(c)(1) provides that it is unlawful for any person in the course of maintaining,
servicing, repairing, or disposing of an appliance (or IPR) to knowingly vent, or
otherwise knowingly release or dispose of, any class I or class II substance used as a
refrigerant in that appliance (or IPR) in a manner which permits the ODS to enter the
environment.
Section 608(c)(2) extends the prohibition in section 608(c)(1) to knowingly
venting or otherwise knowingly releasing or disposing of any refrigerant substitute for
class I or class II substances by any person maintaining, servicing, repairing, or disposing
of appliances or IPR. This prohibition applies to any substitute refrigerant unless the
Administrator determines that such venting, releasing, or disposing does not pose a threat
to the environment. Thus, section 608(c) provides EPA authority to promulgate
regulations to interpret, implement, and enforce this prohibition on venting, releasing, or
disposing of class I or class II substances used as refrigerants and their substitutes, which
we also refer to as the “venting prohibition” in this final action. EPA’s authority under
section 608(c) includes authority to implement section 608(c)(2) by exempting certain
substitutes for class I or class II substances from the venting prohibition when the
Administrator determines that such venting, release, or disposal does not pose a threat to
the environment.
EPA has established regulations clarifying how the venting prohibition in section
608(c) applies to ODS and substitute (e.g., HFCs and perfluorocarbons (PFCs))
refrigerants. These regulations are codified at 40 CFR part 82, subpart F. In relevant part,
they provide that no person maintaining, servicing, repairing, or disposing of an
appliance or industrial process refrigeration may knowingly vent or otherwise release into
the environment any refrigerant (including substitute refrigerants) from such appliances
or industrial process refrigeration, with the exception of certain specified substitutes in
the specified end-uses, as provided in 40 CFR 82.154(a).

EPA has exempted from the venting prohibition several hydrocarbon (HC)
refrigerant substitutes, including R-290, in specific end-uses where the Agency also listed
the substitutes as acceptable, subject to use conditions, under the SNAP program. See, for
example, EPA’s regulations issued May 23, 2014 (79 FR 29682), April 10, 2015 (80 FR
19453), and December 1, 2016 (81 FR 86778).5 Those regulatory exemptions do not
apply to blends of hydrocarbons (HCs) with other refrigerants or containing any amount
of any CFC, HCFC, HFC, or PFC. The exemptions for R-290 by end-use are codified at
40 CFR 82.154(a)(1)(viii).
In establishing those exemptions, EPA determined that for the purposes of CAA
section 608(c)(2), the venting, release, or disposal of such HC refrigerant substitutes in
the specified end-uses does not pose a threat to the environment, considering both the
inherent characteristics of these substances and the limited quantities used in the relevant
applications. See, e.g., 81 FR 86778, December 1, 2016. EPA further concluded that
other authorities, controls, or practices that apply to such refrigerant substitutes help to
mitigate environmental risk from the release of those saturated HC refrigerant substitutes.
B. Does this action apply to me?
The following list identifies regulated entities that may be affected by this rule
and their respective North American Industrial Classification System (NAICS) codes:
•

Plumbing, Heating, and Air Conditioning Contractors (NAICS 238220)

•

All Other Basic Organic Chemical Manufacturing (NAICS 325199)

•

Air Conditioning and Warm Air Heating Equipment and Commercial and
Industrial Refrigeration Equipment Manufacturing (NAICS 333415)

The United States Court of Appeals for the District of Columbia Circuit (“the court”) issued a partial
vacatur of the December 1, 2016, rule “‘to the extent’ it required manufacturers to replace already lawfully
installed HFC substitutes.” See Mexichem Fluor, Inc. v. EPA, Judgment, Case No. 17-1024 (D.C. Cir.,
April 5, 2019), 760 Fed. Appx. 6 (Mem). The court’s decision on the December 1, 2016, rule did not affect
the portion of that rule that exempted certain HC refrigerant substitutes from the venting prohibition. This
final rule is not EPA’s response to the court’s decision.
•

Refrigeration Equipment and Supplies Merchant Wholesalers (NAICS
423740)

•

Recyclable Material Merchant Wholesalers (NAICS 423930)

•

Supermarkets and Other Grocery (except Convenience) Stores (NAICS
445110)

•

Convenience Stores (NAICS 445120)

•

Limited-Service Restaurants (NAICS 722211)

•

Appliance Repair and Maintenance (NAICS 811412)

This list is not intended to be exhaustive, but rather to provide a guide for readers
regarding entities likely to be affected by this action. To determine whether your facility,
company, business, or organization could be affected by this action, you should carefully
examine the regulations at 40 CFR part 82, subpart G, and these revisions. If you have
questions regarding the applicability of this action to a particular entity, consult the
person listed in the FOR FURTHER INFORMATION CONTACT section.
C. What acronyms and abbreviations are used in the preamble?
The following acronyms and abbreviations are used in the preamble of this
document:
AC—Air Conditioning
AEL—Acceptable Exposure Limit
AIHA—American Industrial Hygiene Association
AIM Act—American Innovation and Manufacturing Act of 2020
ANSI—American National Standards Institute
ASHRAE—American Society of Heating, Refrigerating and Air-Conditioning Engineers
ASTM—American Society for Testing and Materials
ATEL—Acute Toxicity Exposure Limit
CAA—Clean Air Act
CAS Reg. No.—Chemical Abstracts Service Registry Identification Number
CBI—Confidential Business Information
CFC—Chlorofluorocarbon
CFR—Code of Federal Regulations
CO2—Carbon Dioxide
DOE—United States Department of Energy
DOT—United States Department of Transportation
DX—Direct Expansion

EEAP—Environmental Effects Assessment Panel
EPA—United States Environmental Protection Agency
FR—Federal Register
GHS—Globally Harmonized System of Classification and Labeling of Chemicals
GWP—Global Warming Potential
HC—Hydrocarbon
HCFC—Hydrochlorofluorocarbon
HCFO—Hydrochlorofluoroolefin
HFC—Hydrofluorocarbon
HFO—Hydrofluoroolefin
HP—Heat Pump
IBC—International Building Code
ICC—International Code Council
ICF—ICF International, Inc.
IEC—International Electrotechnical Commission
IIAR—International Institute of Ammonia Refrigeration
IPCC—Intergovernmental Panel on Climate Change
IPR—Industrial Process Refrigeration
ISO—International Organization for Standardization
LFL—Lower Flammability Limit
MIR—Maximum Incremental Reactivity
NAAQS—National Ambient Air Quality Standards
NAICS—North American Industrial Classification System
NARA—National Archives and Records Administration
NFPA—National Fire Protection Association
ODP—Ozone Depletion Potential
ODS—Ozone-Depleting Substances
OMB—United States Office of Management and Budget
OSHA—United States Occupational Safety and Health Administration
PEL—Permissible Exposure Limit
PFC—Perfluorocarbons
PMS—Pantone® Matching System
ppm—Parts Per Million
PRA—Paperwork Reduction Act
RAL—“Reichs-Ausschuß für Lieferbedingungen und Gütesicherung” Germany’s
National Commission for Delivery Terms and Quality Assurance
RCRA—Resource Conservation and Recovery Act
RFA—Regulatory Flexibility Act
SDS—Safety Data Sheet
SIP—State Implementation Plan
TLV—Threshold Limit Value
TSCA—Toxic Substances Control Act
TWA—Time Weighted Average
UL—UL, formerly known as Underwriters Laboratories, Inc.
UMRA—Unfunded Mandates Reform Act
VOC—Volatile Organic Compound, Volatile Organic Compounds
WEEL—Workplace Environmental Exposure Limit
WMO—World Meteorological Organization
II. What is the Environmental Protection Agency (EPA) finalizing in this action?

This section of the preamble describes EPA’s final listings for certain refrigerants
in specific end-uses, including final use restrictions. In addition, this section provides
responses to comments EPA received on the proposed listings during the public comment
period for the proposed rule (May 24, 2023). The regulatory text for new listings is
codified in appendix Y of 40 CFR part 82, subpart G. The regulatory text for two revised
listings is codified in appendices R and V of 40 CFR part 82, subpart G. The final
regulatory text contains listing decisions for the end-uses discussed throughout this
section.
A. Retail Food Refrigeration—Listing of HFO-1234yf, HFO-1234ze(E), R-454C,
R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in new
stand-alone units, remote condensing units, supermarket systems, and refrigerated food
processing and dispensing equipment and listing of R-454A as acceptable, subject to use
conditions, for use in new remote condensing units and supermarket systems
This final rule lists HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and
R-516A as acceptable, subject to use conditions, for use in all end-use categories under
retail food refrigeration (i.e., stand-alone units, remote condensing units, supermarket
systems, and refrigerated food processing and dispensing equipment). EPA is also listing
R-454A as acceptable, subject to use conditions, for use in two end-use categories under
retail food refrigeration (remote condensing units and supermarket systems). After
consideration and evaluation of comments, EPA is finalizing the listings for HFO1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A in all end-use
categories under retail food refrigeration and R-454A in two end-use categories under
retail food refrigeration as proposed.
EPA is finalizing several use conditions for these end-use categories that are in
common with those finalized for other end-uses (retail food refrigeration, commercial ice
machines, IPR, cold storage warehouses, and ice skating rinks with a remote compressor)

discussed elsewhere in this final rule. Because of this similarity, EPA discusses the use
conditions that apply to all five end-uses in detail in section II.H of this preamble. Briefly
summarized, the common use conditions that EPA is finalizing are: restricting the use of
each refrigerant to new equipment that is specifically designed and clearly marked for
that refrigerant; use consistent with ASHRAE 15-2022 and with UL 60335-2-89 (with
certain exceptions)6, including testing, charge sizes, ventilation, usage space
requirements, and certain hazard warnings and markings.
For use of these substitutes in retail food refrigeration equipment, EPA is also
finalizing the use condition that these refrigerants may only be used in commercial
refrigeration equipment that meets the requirements listed in the American National
Standards Institute (ANSI)/American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE) Standard 15-2022 “Safety Standard for Refrigeration
Systems” (hereafter “ASHRAE 15-2022”). In cases where the final rule includes
requirements that are different than those of ASHRAE 15-2022, EPA is finalizing that the
appliance needs to meet the requirements of this rule in addition to the requirements in
ASHRAE 15-2022. This additional use condition is discussed further in section II.A.4 of
this preamble.
For R-454A in supermarkets and remote condensing units, EPA is finalizing an
additional use condition that this substitute may only be used in equipment with a
refrigerant charge capacity less than 200 pounds or in the high-temperature side of a
cascade system.
1. Background on retail food refrigeration
Retail food refrigeration, an end-use within the SNAP program, encompasses the
Exceptions include equipment that is outside the scope of UL 60335-2-89, such as commercial
refrigeration products with rated voltage of 15,000 V or greater, appliances using flammable refrigerant in
transcritical refrigeration systems, vending machines, and professional ice-cream appliances. In addition,
for equipment installed in situations where that standard refers to "national standards,” refrigerants may be
used in equipment installed consistent with the requirements of ASHRAE 15-2022 without meeting the
requirements of UL 60335-2-89.
equipment used for storing and displaying (generally for sale) food and beverages at
different temperatures necessary for the different products (e.g., chilled and frozen food).
The designs and refrigerating capacities of equipment vary widely to ensure the proper
temperatures are achieved and maintained.
Retail food refrigeration is composed of four categories of equipment: stand-alone
units; refrigerated food processing and dispensing equipment; remote condensing units;
and supermarket systems. EPA treats each of these four end-use categories as a separate
end-use for purposes of our evaluations of the overall risk to human health and the
environment compared to other refrigerants that are available or potentially available for
the same end-use and for purposes of listing substitute refrigerants.
Stand-alone units are refrigerators, freezers, and reach-in coolers (either open or
with doors) where all refrigeration components are integrated and, for the smallest types,
the refrigerant circuit is entirely brazed, welded, or uses threaded fittings. These systems
are charged with refrigerant at the factory and typically require only an electricity supply
to begin operation. Such systems are used to chill and temporarily store perishable items
for commercial sale, such as beverages and food.
As the name suggests, refrigerated food processing and dispensing equipment
dispenses, typically through a nozzle, and often processes a variety of food and beverage
products. For instance, such equipment will process the product by combining
ingredients, mixing, and preparing it at the proper temperature, while others function
mainly as a holding tank to deliver the product at the desired temperature or to deliver
chilled ingredients for processing, mixing, and preparation. Some may use a refrigerant in
a heat pump, or utilize waste heat from the cooling system, to provide hot beverages.
Some may also provide heating functions for melting or dislodging ice, or for sanitation
purposes.
Refrigerated food processing and dispensing equipment can be self-contained or

can be connected via piping to a dedicated condensing unit located elsewhere. Equipment
within this end-use category includes but is not limited to refrigerated equipment used to
process and dispense beverages and food such as: chilled and frozen beverages
(carbonated and uncarbonated, alcoholic and nonalcoholic); frozen custards, gelato, ice
cream, Italian ice, sorbets, and yogurts; milkshakes, “slushies” and smoothies; and
whipped cream.
Remote condensing units typically have refrigerating capacities ranging from
1kW to 20kW (0.3 to 5.7 refrigeration tons). They are composed of one (and sometimes
two) compressor(s), one condenser, and one receiver assembled into a single unit, which
is normally located external to the sales area. This equipment is connected to one or more
nearby evaporator(s) used to cool food and beverages stored in display cases and/or walkin storage rooms. Remote condensing units are commonly installed in convenience stores
and specialty shops such as bakeries and butcher shops.
Typical supermarket systems are also known as multiplex or centralized systems.
They operate with racks of compressors installed in a machinery room; different
compressors turn on to match the refrigeration load necessary to maintain temperatures.
Two main design classifications are used: direct and indirect systems. In the United
States, direct systems are the most widespread. The majority of supermarkets in the
United States use centralized direct expansion (DX) systems to cool their display cases.7
The refrigerant circulates from the machinery room to the sales area, where it evaporates
in display-case heat exchangers, and then returns in vapor phase to the suction headers of
the compressor racks. The supermarket walk-in cold rooms are often integrated into the
system and cooled similarly, but an alternative option is to provide a dedicated
condensing unit for a given storage room. Another type of supermarket design, often
referred to as a distributed refrigeration system, uses an array of separate compressor

www.epa.gov/greenchill/advanced-refrigeration.

racks located near the display cases rather than having a central compressor rack system.
Each of these smaller racks handles a portion of the supermarket load, with five to ten
such systems in a store.
Indirect supermarket system designs include secondary loop systems and cascade
refrigeration. Indirect systems use a chiller8 or other refrigeration system to cool a
secondary fluid that is often circulated throughout the store to the cases. Examples of
secondary fluids include water, brine, propylene glycol, air, and carbon dioxide (CO2).
Compact chiller versions of an indirect system rely on a lineup of ten to 20 units, each
using small charge sizes. As the refrigeration load changes, more or fewer of the chillers
are active. Compact chillers are used in a secondary loop system whereby the chillers
cool a secondary fluid that is then circulated throughout the store to the display cases.
Each compact chiller is an independent unit with its own refrigerant charge, reducing the
potential for refrigerant to be released from leaks or for a catastrophic failure. Cascade
systems use a compressor to raise the low-temperature, secondary fluid from lowtemperature conditions up to an intermediate temperature while a separate, primary
refrigerant system uses a different, higher temperature refrigerant to condense the
secondary fluid. Each system within the cascade design contains its own refrigerant
charge, allowing the use of different refrigerants in each system. This application has
generally used a lower global warming potential (GWP) refrigerant, specifically CO2 (R744), in the low-temperature system, with a variety of refrigerants in the hightemperature system.
Refrigerant choice may depend on the refrigerant charge size of the equipment,
desired temperature, system performance, energy efficiency, and health, safety and
environmental considerations, and cost among other things. In addition to regulations

Chillers used in supermarket systems are considered within the supermarket end-use under SNAP and the
supermarket subsector under the Technology Transitions Program.
pursuant to the SNAP program and the AIM Act, other Federal or local regulations may
also affect refrigerant choice. For instance, regulations from OSHA may restrict or place
requirements on the use of some refrigerants, such as ammonia (R-717). Building codes
from local and State agencies may also incorporate limits on the types and amounts of
particular refrigerants used.
2. What are the ASHRAE classifications for refrigerant flammability?
The ANSI/ASHRAE Standard 34-2022 “Designation and Safety Classification of
Refrigerants” (hereafter “ASHRAE 34-2022”) assigns a safety group classification for
each refrigerant which consists of two to three alphanumeric characters (e.g., A2L or B1).
The initial capital letter indicates the toxicity, and the numeral denotes the flammability.
ASHRAE classifies Class A refrigerants as refrigerants for which toxicity has not been
identified at concentrations less than or equal to 400 parts per million (ppm) by volume,
based on data used to determine threshold limit value-time-weighted average (TLVTWA) or consistent indices. Class B signifies refrigerants for which there is evidence of
toxicity at concentrations below 400 ppm by volume, based on data used to determine
TLV-TWA or consistent indices.
The refrigerants are also assigned a flammability classification of 1, 2, 2L, or 3.
Tests for flammability are conducted in accordance with American Society for Testing
and Materials (ASTM) E681 using a spark ignition source at 140 °F (60 °C) and 14.7 psia
(101.3 kPa).9 The flammability classification “1” is given to refrigerants that, when
tested, show no flame propagation. The flammability classification “2” is given to
refrigerants that, when tested, exhibit flame propagation, have a heat of combustion less
than 19,000 kJ/kg (8,169 Btu/lb), and have a lower flammability limit (LFL) greater than
0.10 kg/m3. The flammability classification “2L” is given to refrigerants that, when

ASHRAE, 2022b. ANSI/ASHRAE Standard 34-2022: Designation and Safety Classification of
Refrigerants.
tested, exhibit flame propagation, have a heat of combustion less than 19,000 kJ/kg
(8,169 Btu/lb), have an LFL greater than 0.10 kg/m3, and have a maximum burning
velocity of 10 cm/s or lower when tested in dry air at 73.4 °F (23.0 °C) and 14.7 psi
(101.3 kPa). The flammability classification “3” is given to refrigerants that, when tested,
exhibit flame propagation and that either have a heat of combustion of 19,000 kJ/kg
(8,169 Btu/lb) or greater or have an LFL of 0.10 kg/m3 or lower.
For flammability classifications, refrigerant blends are designated based on the
worst case of formulation for flammability and the worst case of fractionation for
flammability determined for the blend.

Increasing Flammability

Figure 1. Refrigerant Safety Group Classification
Higher
Flammability
Flammable
Lower
Flammability
No Flame
Propagation

Safety Group
A3

B3

A2

B2

A2L
A1

B2L
B1

Lower
Higher
Toxicity
Toxicity
Increasing Toxicity

Using these safety group classifications, ASHRAE 34-2022 categorizes HFO1234yf, HFO-1234ze(E), HFC-32 and the refrigerant blends R-454A, R-454C, R-455A,
R-457A, and R-516A, which are discussed in this section of this rule, as being in the A2L
Safety Group, while R-290 is in the A3 Safety Group.
3. What are HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A and how do they compare to other refrigerants in the same
end-use?
HFO-1234yf and HFO-1234ze(E) are lower flammability single component
refrigerants, and R-454A, R-454C, R-455A, R-457A, and R-516A are lower flammability

refrigerant blends, all with an ASHRAE safety classification of A2L.10 The respective
Chemical Abstracts Service Registry Identification Numbers (CAS Reg. Nos.) of HFO1234yf, HFO-1234ze(E), and the components of the refrigerant blends are listed here.
HFO-1234yf, also known by the trade names “Solstice® yf” and “Opteon™ YF,”
is also known as 2,3,3,3-tetrafluoroprop-1-ene (CAS Reg. No. 754-12-1). HFO1234ze(E), also known by the trade names “Solstice® ze” and “Solstice® 1234ze,” is also
known as trans-1,3,3,3,tetrafluoroprop-1-ene (CAS Reg. No. 29118-24-9). R-516A, also
known by the trade name “Forane® 516A,” is a blend consisting of 77.5 percent HFO1234yf, 14 percent HFC-152a, and 8.5 percent HFC-134a. R-457A, also known by the
trade name “Forane® 457A,” is a blend consisting of 18 percent HFC-32, 12 percent
HFC-152a, and 70 percent HFO-1234yf. R-455A, also known by the trade name
“Solstice® L40X,” is a blend consisting of 21.5 percent HFC-32, 75.5 percent HFO1234yf, and three percent R-744 (CO2). R-454A, also known by the trade name
“Opteon™ XL 40,” is a blend consisting of 35 percent HFC-32 and 65 percent HFO1234yf. R-454C, also known by the trade name “Opteon™ XL 20,” is a blend consisting
of 21.5 percent HFC-32 and 78.5 percent HFO-1234yf.
Redacted submissions and supporting documentation for HFO-1234yf, HFO1234ze(E), R-454A, R-454C, R-455A, R-457A, and R-516A are provided in the docket
for this rule (EPA-HQ-OAR-2023-0043) at https://www.regulations.gov. EPA performed
a risk screening assessment to examine the health and environmental risks of each of
these refrigerants. These risk screens are available in the docket for this

EPA previously listed HFO-1234yf as acceptable, subject to use conditions, in motor vehicle AC in lightduty vehicles (74 FR 53445, October 19, 2009), in heavy-duty pickup trucks and complete heavy-duty vans
(81 FR 86778, December 1, 2016) and in nonroad vehicles and service fittings for small refrigerant cans
(87 FR 26276, May 4, 2022). EPA previously listed R-454A, R-454C, and R-457A as acceptable, subject
to use conditions, as a substitute in residential and light commercial AC and heat pumps (86 FR 24444,
May 6, 2021).
rule.11,12,13,14,15,16,17
Environmental information: HFO-1234yf, HFO-1234ze(E) and R-454A, R-454C,
R-455A, R-457A, and R-516A have ozone depletion potentials (ODPs) of zero.
HFO-1234yf and HFO-1234ze(E) both have a GWP of one.18, 19 The refrigerant
blends are made up of the components HFC-32, HFC-125, HFC-152a, CO2, and HFO1234yf, which have GWPs of 675, 3,500, 124, one, and one, respectively.20 If these
values are weighted by mass percentage, then R-454A, R-454C, R-455A, R-457A, and
R-516A have GWPs of about 237, 146, 146, 137, and 140, respectively.
HFO-1234yf, HFO-1234ze(E), and the other components of the refrigerant
blends, CO2, HFC-32, HFC-125, and HFC-152a, are excluded from EPA’s regulatory
definition of volatile organic compounds (VOC) (see 40 CFR 51.100(s)) addressing the
development of State Implementation Plans (SIPs) to attain and maintain the National
Ambient Air Quality Standards (NAAQS). That definition provides that “any compound
of carbon” which “participates in atmospheric photochemical reactions” is considered a

ICF, 2024a. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: HFO1234yf.
12 ICF, 2024b. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: HFO1234ze(E) (Solstice® ze, Solstice® 1234ze)
13 ICF, 2024c. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: R454A (Opteon® XL40).
14 ICF, 2024d. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: R454C (Opteonâ„¢ XL20).
15 ICF, 2024e. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: R455A (Solstice® L40X).
16 ICF, 2024f. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: R457A (Forane® 457A).
17 ICF, 2024g. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute: R516A (Forane® 516A).
18 World Meteorological Organization (WMO) (2022). Burkholder et al. Appendix A, Table A-5 in
Scientific Assessment of Ozone Depletion: 2022, GAW Report No. 278, 509 pp.; WMO, Geneva,
Switzerland, https://ozone.unep.org/science/assessment/sap. (WMO, 2022)
19 Hodnebrog Ø. et al., 2013. Hodnebrog Ø., Etminan, M., Fuglestvedt, J.S., Marston, G., Myhre, G.,
Nielsen, C.J., Shine, K.P., Wallington, T.J.: Global Warming Potentials and Radiative Efficiencies of
Halocarbons and Related Compounds: A Comprehensive Review, Reviews of Geophysics, 51, 300–378,
doi:10.1002/rog.20013, 2013.
20 Unless otherwise specified, GWP values are 100-year values from Intergovernmental Panel on Climate
Change (IPCC) (2007) Climate Change 2007: The Physical Science Basis. Contribution of Working Group
I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. S. Solomon, D. Qin,
M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.). Cambridge University
Press. Cambridge, United Kingdom 996 pp.
VOC unless expressly excluded in that provision based on a determination of “negligible
photochemical reactivity.”21
None of the exemptions to the venting prohibition under CAA 608(c)(2) listed in
82.154(a)(1) apply to HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, or R-516A.
Flammability information: HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R455A, R-457A, and R-516A have lower flammability, with an ASHRAE flammability
classification of 2L. EPA evaluated flammability risk by evaluating reasonable worstcase and more typical, yet conservative, scenarios to model the effects of releases of these
substitutes in the listed end-uses. These refrigerants are not expected to present a
flammability concern provided the use conditions are followed. The use conditions
provide additional safety measures and labeling requirements (e.g., visible warning
statement and red coloring on the pipes, hoses, and devices which contain refrigerant)
that make equipment owners, consumers, fire marshals, and emergency first responders
aware of the presence of a flammability hazard.
Toxicity and exposure data: HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R455A, R-457A, and R-516A have an ASHRAE toxicity classification of A (lower
toxicity). Potential health effects of exposure to these refrigerants include drowsiness or
dizziness. The refrigerants may also irritate the skin or eyes or cause frostbite. At
sufficiently high concentrations, the refrigerants may cause irregular heartbeat. The
refrigerants could cause asphyxiation if air is displaced by vapors in a confined space.
These potential health effects are common to many refrigerants.
OSHA has established a Permissible Exposure Limit (PEL) for CO2 of 5,000 ppm
as an 8-hr TWA. The American Industrial Hygiene Association (AIHA) has established

21 Definitions under title 40 chapter I subchapter C part 51 subpart F CFR 51.100 can be found at

https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-51/subpart-F/section-51.100.

Workplace Environmental Exposure Limits (WEELs) of 1,000 ppm as an 8-hr TWA for
HFC-32, HFC-125, and HFC-152a and 500 ppm as an 8-hr TWA for HFO-1234yf. The
manufacturer of HFO-1234ze(E) recommends 800 ppm as an 8-hr TWA for that
chemical, as does ASHRAE 34-2022. The manufacturers of R-454A, R-454C, R-455A,
R-457A, and R-516A recommend acceptable exposure limits (AELs) for the workplace,
respectively, of 690, 615, 650, 650, and 590 ppm on an 8-hr TWA for these blends.22
EPA anticipates that users will be able to meet the OSHA PEL, AIHA WEELs, and
manufacturers’ AELs and address potential health risks by following requirements and
recommendations in the manufacturers’ safety data sheets (SDSs), the final use
conditions (including adherence to UL 60335-2-89 and ASHRAE 15-2022), and other
safety precautions common to the refrigeration and AC industry.
Comparison to other substitutes in these end-uses: HFO-1234yf, HFO-1234ze(E),
R-454A, R-454C, R-455A, R-457A, and R-516A all have an ODP of zero, comparable to
or lower than some of the acceptable substitutes in these end-uses, such as CO2, with an
ODP of zero.
For new refrigerated food processing and dispensing equipment R-454C, R-455A,
R-457A, and R-516A have GWPs ranging from 140 to 150, higher than that of CO2, an
acceptable substitute in this end-use category, with a GWP of one, while HFO-1234yf
and HFO-1234ze(E) have comparable GWPs to CO2 of one. The GWPs of HFO-1234yf,
HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A are lower than those of other
acceptable HFC-134a, with GWPs of approximately 600, 630, and 1,430, respectively.
For new remote condensing units and supermarket systems, R-454A, R-454C, R455A, R-457A, and R-516A have GWPs ranging from 140 to 237, higher than that of
ammonia and CO2, acceptable substitutes in these end-use categories, with GWPs of zero

The 8-hr TWA AEL recommendations of these refrigerant blends are based upon a mass-weighting of
the PEL and WEELs of their components. ASHRAE 34-2022 also recommends these occupational
exposure limits.
and one, respectively, while HFO-1234yf and HFO-1234ze(E) have comparable GWPs to
CO2 of one. The GWPs of HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A are lower than those of some of the acceptable substitutes for new
remote condensing units and new supermarket systems, such as R-450A, R-513A, HFC134a, R-407A, and R-404A, with GWPs of approximately 601, 630, 1,430, 2,110, and
3,922, respectively.
For new stand-alone units R-454C, R-455A, R-457A, and R-516A have GWPs
ranging from 140 to 150, higher than some of the acceptable substitutes in this end-use
category such as CO2, R-290, and R-441A with GWPs of one, three, and less than five,
while HFO-1234yf and HFO-1234ze(E) have comparable GWPs to CO2, R-290, and R441A of one. The GWPs of HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A,
R-457A, and R-516A are lower than some of the acceptable substitutes for new standalone units, such as R-450A and R-513A, with GWPs of 601 and 630, respectively. As of
January 1, 2025, certain HFCs and HFC blends will be subject to restrictions in new
stand-alone units under the Technology Transitions Rule. In light of that upcoming
restriction, EPA is listing HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A to provide additional lower-GWP, refrigerants in this end-use. This
upcoming restriction, and the corresponding value of providing additional lower-GWP
refrigerants in this end-use, are additional considerations that informed EPA’s decision
on this listing.
Information regarding the toxicity of other available alternatives is provided in the
listing decisions previously made (see https://www.epa.gov/snap/retail-foodrefrigeration). Toxicity risks of use, determined by the likelihood of exceeding the
exposure limit, of HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A,
and R-516A in these end-uses are evaluated in the risk screens referenced previously. The
toxicity risks of using HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-

457A, and R-516A in retail food refrigeration equipment are comparable to or lower than
toxicity risks of other available substitutes in the same end-uses. Toxicity risks of the
refrigerants can be minimized by use consistent with UL 60335-2-89 and ASHRAE 152022–as required by the use conditions for these listings. EPA also anticipates that
service technicians working with these systems will adhere to recommendations in the
manufacturers’ SDS for these refrigerants and other safety precautions common in the
refrigeration and AC industry.
The flammability risks with HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R455A, R-457A, and R-516A in these end-uses, determined by the likelihood of exceeding
their respective LFLs, are evaluated in the risk screens referenced previously. Based on
those risk screens, EPA’s view is that while these refrigerants may pose greater
flammability risk than other available substitutes in the same end-uses, this risk can be
minimized by use consistent with UL 60335-2-89, ASHRAE 15-2022, as well as
recommendations in the manufacturers’ SDS and other safety precautions common in the
refrigeration and AC industry. EPA is finalizing use conditions to reduce the potential
risk associated with the flammability of these alternatives so that they will not pose
greater overall risk to human health and the environment than other acceptable substitutes
in this end-use category.
In addition, the refrigerants listed through this action have lower GWPs than most
other refrigerants currently in use today, though EPA notes that this is expected to shift in
the future as entities begin complying with the restrictions under the 2023 Technology
Transitions Rule for new equipment. These refrigerants provide additional lower-GWP
options for situations where other refrigerants with lower GWPs may not be suitable.
Given the wide range of applications for retail food refrigeration, not all refrigerants
listed as acceptable under SNAP will be suitable for the range of equipment in the retail
food refrigeration end-use or in the four end-use categories within retail food

refrigeration. In this context, listing additional refrigerants as acceptable under SNAP
provides additional options and increases the availability of substitutes for the full range
of retail food refrigeration equipment with lower-GWP refrigerants, which is anticipated
to lead to lower overall risk to human health and the environment. Accordingly, based on
EPA’s evaluation of the information discussed above and consideration of overall risk to
human health and the environment, EPA is listing HFO-1234yf, HFO-1234ze(E), R454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in
all types of retail food refrigeration equipment. In addition, to account for the challenges
for finding lower-GWP refrigerants with higher capacity for remote condensing units and
supermarket systems with moderate charge sizes and for cascade systems, EPA is listing
R-454A as acceptable, subject to use conditions, for use in remote condensing units and
supermarket systems with a charge size capacity less than 200 pounds or for use in the
high-temperature side of a cascade system.
4. Why is EPA finalizing these specific use conditions?
This final rule applies to end-uses covered by UL 60335-2-89. This standard
applies to commercial and industrial refrigeration equipment, including the SNAP enduses of retail food refrigeration, commercial ice machines, IPR, cold storage warehouses,
and ice skating rinks. ASHRAE 15-2022 also applies to these refrigeration systems.
UL 60335-2-89, as discussed in section II.H of this preamble, indicates that
refrigerant charges greater than a specific amount (called “m3” in the standard and based
on the refrigerant’s LFL) should be determined using national standards that apply, such
as ASHRAE 15-2022. Hence, EPA is requiring adherence to both standards, when
applicable, as use conditions for remote condensing units and supermarket systems.
EPA is incorporating by reference ASHRAE 15-2022 and UL 60335-2-89 in use
conditions that apply to use of the A2L refrigerants listed through this action in new
remote condensing units and supermarket systems. Where the requirements specified in

this final rule and ASHRAE 15-2022 differ, the requirements of this final rule apply.
A partial summary of ASHRAE 15-2022 is provided here for information only.
This is not meant to be a full explanation of the standard or how it is applied; for
additional detail, please consult the standard. ASHRAE 15-2022 specifies requirements
for refrigeration systems, based on the safety group classification of the refrigerant, the
type of occupancy where the system is located, and whether refrigerant-containing parts
of the system enter the space or ductwork such that leakage in the space is deemed
“probable.” “High-probability” installations are those such that leaks or failures will
result in refrigerant entering occupied space. Occupancies are divided into six
classifications: institutional, public assembly, residential, commercial, large mercantile,
and industrial. Examples of these include jails, theaters, apartment buildings, office
buildings, shopping malls, and chemical plants, respectively.
Sections 7.2 and 7.3 of ASHRAE 15-2022 determine the maximum amount of
refrigerant allowed in the system, while section 7.4 provides an option to locate
equipment outdoors or in a machinery room constructed and maintained under conditions
specified in the standard. Section 7.7 of ASHRAE 15-2022 addresses the A2L
refrigerants listed in this action when used in “high-probability” systems that are not for
human comfort, including requirements for nameplates, labels, refrigerant detectors
(under certain conditions), airflow initiation or other actions (if a rise in refrigerant
concentration is detected), and other restrictions.
ASHRAE 15-2022 is undergoing continuous maintenance with publication of
periodic addenda and is typically updated and republished every three years. Although
there were additional changes to ASHRAE 15-2022 between issuance of the proposed
rule and now, EPA was not able to review and seek comment on use conditions based on
those more recent changes after publication of the proposal. EPA is therefore not
including addenda or other changes made to ASHRAE 15-2022 after the date of the

proposed rule.
EPA is finalizing an additional use condition for R-454A in supermarkets and
remote condensing units. This refrigerant may only be used either in equipment with a
refrigerant charge capacity less than 200 pounds or in the high-temperature side of a
cascade system. The Agency is finalizing this use condition to allow use of R-454A less
broadly than for the other refrigerants being listed for use in remote condensing units and
supermarket systems because its GWP is higher than those of the other listings for these
end-use categories (about 237, compared to one to 150). EPA’s understanding is that
there are two particular situations where use of refrigerants is likely to be more
constrained to minimize risks to human health and the environment, and thus, additional
refrigerant options may be helpful.
The first of those situations is where ASHRAE 15-2022 identifies a refrigerating
system as having a “high probability” that leaked refrigerant from a failed connection,
seal, or component could enter an occupied area. ASHRAE 15-2022 and UL 60335-2-89
effectively set charge limits for A2L refrigerants to less than 260 times the LFL
(approximately 200 pounds for A2L refrigerants and ranging from roughly 120 to 250
pounds for the particular refrigerants listed in this rule) for applications inside a
supermarket or convenience store that are open to the general public. In contrast, larger
charge sizes could be used in “low-probability” locations where the general public is
unlikely to come in contact with the refrigerant, such as systems used in industrial
occupancies, outdoors, or in a machinery room with access restricted to store employees.
Where the general public is unlikely to come into contact with any leaked refrigerant,
there would be fewer space constraints and greater flexibility in equipment design, so
refrigeration system designers can accommodate a narrower set of refrigerants.
Conversely, where the general public is more likely to come into contact with any leaked
refrigerant in an interior space, which are not industrial occupancies, refrigerant charge

capacities of a system would be less than 200 pounds. In addition, in such public spaces
there would be more space constraints, less flexibility in equipment design, and
potentially stricter code requirements. EPA recognizes that these may be situations where
R-454A can be used where those other refrigerants cannot, especially where space is
constrained. Therefore, R-454A fills a gap in the stated end-uses where lower-GWP
refrigerant alternatives posing less of a risk to human health and the environment are not
as available, and R-454A’s GWP of approximately 240 and similar toxicity and
flammability profiles would pose lower overall risk to human health and the
environment. Listing R-454A for supermarket systems and remote condensing units with
smaller refrigerant charges provides an additional refrigerant to manage safety (in
particular, flammability and toxicity) while achieving adequate performance where there
may be more constraints. As some public commenters stated, R-454A has a higher
volumetric capacity than the other A2L refrigerants with lower GWPs being listed in this
rule, which means less refrigerant is needed and smaller refrigeration equipment can
achieve the same cooling effect. Therefore, EPA is listing R-454A as acceptable, subject
to use conditions, only for supermarket systems and remote condensing units with a use
condition that refrigerant charge capacity shall be less than 200 pounds in order to
mitigate risk to human health and the environment that could be associated with higher
GWPs.
The second situation where use of refrigerants is likely to be more constrained is
for use in the high-temperature side of cascade systems used for supermarket systems and
remote condensing units. As discussed in section II.A.1 of this preamble, “Background
on retail food refrigeration,” each side23 of a cascade system uses a different refrigerant
that is most suitable for the given temperature range. High-temperature systems, or the

23 Each side of the cascade system is a complete refrigeration system with a compressor, condenser, and

evaporator.

“high-temperature side,” have typically used HFCs as a refrigerant; however, it is
technologically achievable and has become more common to use ammonia in the hightemperature side. For lower temperature systems, or the “low-temperature side” of the
cascade system, refrigerants with low boiling points such as R-744 can be used.
Considerations for the choice of refrigerants on either side of cascade systems are
influenced by many factors including, but not limited to, a refrigerant’s toxicity and
flammability, its temperature glide, and its suitability for lower temperature applications.
Using flammable or toxic refrigerants, such as ammonia, on the high-temperature side of
a cascade system may be limited in certain circumstances (e.g., based on building codes
and/or industry safety standards). There are multiple substitutes available for the lowtemperature side of a cascade system with GWPs lower than that of R-454A, but there are
fewer options for the high-temperature side. Therefore, EPA is listing R-454A as
acceptable, subject to use conditions, when it is used in the high-temperature side of
cascade systems. This action expands the refrigerant options that can comply with local
building codes and industry safety standards while meeting the more challenging
application of the high-temperature side of a cascade system, and allowing for a
refrigerant that would pose lower overall risks to human health and the environment than
refrigerants that would otherwise be used.
5. What additional information is EPA including in these listings?
EPA is providing additional information related to these listings. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the refrigerant under the SNAP program. However,
EPA encourages users of substitutes to apply all statements in the “Further Information”
column in their use of these refrigerants. The additional information applies to multiple
end-uses covered in this final rule. See section II.H.2 of this preamble for discussion on
what additional information EPA is including in these listings.

6. How is EPA responding to comments on retail food refrigeration?
Comment: For the retail food refrigeration end-use, two commenters mentioned
the proposed limitation on the use of R-454A and requested greater flexibility for that
refrigerant and end-use. Both commenters indicated that R-454A is a higher capacity and
more efficient refrigerant compared to alternatives with GWPs less than 150. The
commenters stated that R-454A would provide greater flexibility to meet DOE efficiency
requirements and claimed thermodynamic similarities to other refrigerants (R-404A, R448A, and R-449A). One commenter requested that EPA not restrict R-454A in the high
side of a cascade system and that R-454A be approved for use in stand-alone units.
Another commenter requested that EPA list R-454A as acceptable in all retail food
refrigeration end-uses (stand-alone units, remote condensing units, supermarket systems,
and refrigerated food processing and dispensing equipment). This commenter stated that
EPA has sufficient information in the docket to allow EPA to add R-454A as acceptable
in stand-alone units and refrigerated food processing and dispensing equipment, pointing
to R-454A’s zero ozone depletion potential and A2L classification.
Response: EPA acknowledges the commenters’ request for greater flexibility to
use R-454A. As discussed in section II.A.4 of this preamble, under the listings finalized
in this rule, R-454A is acceptable, subject to use conditions, in the high side of a
supermarket cascade system. Concerning the suggestion that R-454A would provide
greater flexibility to meet DOE’s energy conservation standards, EPA notes that EPA’s
SNAP program and DOE’s program for energy conservation standards operate under
separate authorities. If EPA had information showing that commercial refrigeration
equipment manufactured using other refrigerants with lower GWPs were unable to be
used in this application, EPA might consider broader use of R-454A in the future given
there may not be other available or potentially available low-GWP substitutes for this
application; however, absent such information, EPA is retaining the use conditions for R-

454A in supermarket systems and remote condensing units in this final rule as proposed.
In response to comments supporting approval of R-454A in additional retail food
end-use categories beyond supermarket systems and remote condensing units, such as
stand-alone units and refrigerated food processing and dispensing equipment, EPA is not
taking that action in this final rule because EPA did not propose to list R-454A and has
not completed our consideration or analysis needed to reach a final decision whether to
list this refrigerant in these other retail food end-uses. In response to the commenters’
points about energy efficiency and capacity, these factors are not ones that are considered
in 40 CFR 82.180(a)(7). Moreover, EPA notes that under the final Technology
Transitions Rule (88 FR 73098; October 24, 2023), refrigerants containing HFCs used in
retail food refrigeration—stand-alone units are limited to those with a GWP less than 150
beginning January 1, 2025; thus, even if EPA were to list R-454A as acceptable under the
SNAP program, it still could not be used in stand-alone units after that date. EPA is
finalizing the listings for R-454A as proposed, including listings for retail food
refrigeration—supermarket systems and retail food refrigeration—remote condensing
units, as acceptable, subject to use conditions.
Comment: Two commenters suggested that allowing R-454A would smooth the
transition to low-GWP refrigerants in stand-alone units, enabling the industry to meet
timing goals of the Technology Transitions Rule. A different commenter urged EPA to
list R-454A for use in self-contained equipment. The third commenter stated that the
quantity used in self-contained equipment is less than that used in remote equipment,
thereby reducing the risk of any negative outcomes. This same commenter claimed that
small companies do not have sufficient design resources to meet deadlines for both selfcontained and remote equipment for different refrigerants. The commenter stated that
allowing the use of R-454A in both self-contained and remote equipment would greatly
reduce the time needed to transition to lower-GWP refrigerants.

Response: In response to the first two commenters’ suggestion that listing R454A as acceptable for stand-alone units would enable industry to meet the timing goals
of the Technology Transitions Rule, we do not agree that R-454A is needed for timely
compliance with that restriction. There are already substitutes that meet the 150 GWP
limit available on the market for stand-alone retail food refrigeration. For example, R-290
has been listed as acceptable and has been used in stand-alone units for more than a
decade. The Agency is aware of a number of substitutes, including R-290, which will be
more broadly allowed, with larger charge sizes, through this rulemaking. Therefore, the
Agency disagrees with the first two commenters that expanding the use of R-454A in this
end-use is needed to meet requirements of the Technology Transitions Rule because there
are already substitutes available in use for this purpose. EPA interprets the third
commenter’s request for use of R-454A in self-contained equipment to apply to retail
food refrigeration (stand-alone units) and to retail food refrigeration (refrigerated food
processing and dispensing equipment) that is self-contained, since EPA proposed that all
commercial ice machines could use R-454A, and other types of appliances covered by
this rule are not self-contained. EPA expects that such equipment in many cases could
use other refrigerants with a GWP lower than R-454A’s GWP of 237, such as R-290, R471A, R-454C, R-455A, or R-516A, with GWPs from three to less than 150. EPA also
notes that under the final Technology Transitions Rule (88 FR 73098; October 24, 2023),
refrigerants containing HFCs used in retail food refrigeration—stand-alone units are
limited to those with a GWP less than 150 beginning January 1, 2025; thus, even if EPA
were to list R-454A as acceptable for stand-alone units under the SNAP program, it still
could not be used after that date. EPA also notes that for larger self-contained
commercial ice machines with harvest capacities above certain levels, EPA is finalizing
R-454A as acceptable, subject to use conditions (see section II.C.6 of this preamble).
Comment: One commenter recommended that EPA list HFO-1234yf, HFO-

1234ze(E), R-454A, R-454C, R-455A, R-457A, and R-516A as acceptable for use in
packaged systems in retail food refrigeration (e.g., walk-in coolers and freezers) as it was
unclear if EPA intended the proposed listings to apply to packaged refrigeration systems.
The commenter also asserted that the definitions for packaged refrigerating units in
EPA’s proposed Technology Transitions Rule and UL 60335-2-89 match and that the
industry consensus standard that EPA proposed to incorporate by reference already
includes such equipment within its scope.
Response: In response to this comment, EPA is clarifying that packaged
refrigerating units fall within the same categories where the Agency is finalizing
acceptable listings for those refrigerants. UL 60335-2-89 defines a packaged refrigerating
unit as "a factory assembled unit for performing the complete refrigeration cycle
(compressing gas, condensation or gas cooling, and evaporation) comprising powerdriven refrigerant compressor(s) with motors, condensers or GAS COOLERS24, liquid
receivers, interconnection pipe work, and ancillary equipment, all mounted on a common
base." EPA classifies packaged refrigerating units for retail food refrigeration, such as
walk-in coolers or freezers, as belonging either to the end-use category ‘supermarket
system’ if the refrigerant is supplied on the same multi-compressor refrigerant circuit
used to cool food elsewhere in the store or within the end-use category ‘remote
condensing unit’ if only a one- or two-compressor system is used (generally dedicated to
just the individual walk-in cooler or freezer). (See also July 20, 2015; 80 FR 42901). If
the packaged refrigerating unit is completely self-contained with no remote condenser,
then it would belong to retail food refrigeration—stand-alone units. EPA proposed, and is
finalizing, listings for HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A as acceptable, subject to use conditions, in retail food refrigeration—
supermarket systems and retail food refrigeration—remote condensing units. In addition,

This term is capitalized in the original text of UL’s standard.

EPA proposed, and is finalizing, listings for HFO-1234yf, HFO-1234ze(E), R-454C, R455A, R-457A, and R-516A as acceptable, subject to use conditions, for retail food
refrigeration—stand-alone units.
Comment: One commenter provided detailed comments on ice cream makers,
requesting revisions to the proposal so they become an eligible end-use within the retail
food refrigeration sector for the newly listed refrigerants in the final rule. The commenter
noted that additional standards would need to be referenced in the final rule for ice cream
makers to be included. Specifically, ice cream makers fall under UL 621 in North
America and International Electrotechnical Commission (IEC) 60355-2-118
internationally; they are not in the scope of UL 60355-2-89. As such, the proposal would
prevent ice cream equipment from using certain flammable low-GWP refrigerants, even
when UL 621 and IEC 60335-2-118 have been updated to allow these substances. The
commenter requested that EPA expand the use conditions for the food processing and
dispensing equipment category to follow all relevant UL and IEC standards. The
commenter added that the proposed listings for the sector would increase the cost of
equipment due to the need to mitigate high-temperature discharges for refrigerants like R454C and R-455A using special valves and compressors.
Response: EPA agrees with the commenter that equipment for ice cream makers
is covered by UL 621 and not by UL 60335-2-89. EPA did not propose to require
adherence to UL 621 as a use condition and notes that this standard is currently under
development to address the safe use of flammable refrigerants. Therefore, the Agency is
not adding requirements in the final rule specific to ice cream makers. EPA will continue
to consider changes to relevant standards, and the Agency may consider whether any
revisions to the SNAP regulations should be proposed at a future date. In this final rule,
listings for refrigerated food processing and dispensing equipment do not apply to
equipment that is manufactured according to UL 621, i.e., commercial ice cream makers.

In response to comments related to the cost of equipment for some of the listed
refrigerants, EPA notes this rule does not require the use of any specific refrigerant;
rather, this rule establishes requirements that allow for the safe use of the listed
refrigerants, such that they do not pose overall greater risk to human health and the
environment.
Comment: Two commenters claimed that the proposed rule’s statement that the
smallest types of retail food refrigeration utilize either brazed or welded refrigerant
circuits was incorrect. The commenter stated that thread fittings are used in some cases
and requested that this be accounted for in the final rule. Another commenter added that
EPA had indicated that small units may be fully brazed and stated that some units may
have components with screw fittings like cast iron compressors. They commented that
regulations for A2L refrigerants should not require connections that are all brazed.
Response: EPA agrees with the comments regarding the incomplete and incorrect
statement that the smallest types of retail food refrigeration utilize either brazen or
welded refrigerant circuits. EPA did not intend the statement to imply that brazed
connections would be required. In response to these comments, the description in section
II.A.1 of this preamble also includes threaded fittings.
B. Retail Food Refrigeration—Listing R-290 as acceptable, subject to use
conditions, for use in new refrigerated food processing and dispensing equipment and
revision of the use conditions provided in the previous listings of R-290 as acceptable,
subject to use conditions, for use in new stand-alone units
This final rule lists R-290 as acceptable, subject to use conditions, as a substitute
for use in one additional end-use category under retail food refrigeration (i.e., new
refrigerated food processing and dispensing equipment). Further, EPA is also amending
existing use conditions in the listing of R-290 as acceptable, subject to use conditions, for
use in new stand-alone units. More specifically, EPA previously listed R-290 as

acceptable, subject to use conditions, in new stand-alone units in SNAP Rule 17 (76 FR
78832, December 20, 2011). One of the use conditions established in that rule was
adherence to an earlier standard, UL 471. In this final rule, we are revising those use
conditions to be consistent with the most recent U.S. national standard for retail food
refrigeration equipment, UL 60335-2-89. Among other things, these revisions will allow
safe use of larger charge sizes of R-290 than under UL 471, which will allow for broader
use of R-290 as an alternative in these end-uses. Similar use conditions apply to other
refrigerants with lower flammability in this SNAP action in section II.A of this preamble.
The final use conditions are allowed for such equipment manufactured on or after the
effective date of this final rule and do not apply to nor affect equipment manufactured
before that effective date.
This revision to the use conditions incorporates by reference a newer industry
standard, changing the reference from Supplement SB in the 10th edition of UL 471,
“Commercial Refrigerators and Freezers,” which was required in the earlier SNAP listing
for R-290, to UL 60335-2-89. EPA is providing a transition period from the effective date
of this final rule through September 29, 2024, during which stand-alone units
manufactured with R-290 may follow either the earlier UL 471 standard or UL 60335-289. After the transition period ends, new stand-alone units manufactured with R-290 must
follow UL 60335-2-89 for purposes of the SNAP program, unless the new stand-alone
units remain essentially unchanged from an earlier model or design that was already ULlisted to the earlier UL 471 standard. Under EPA’s understanding of these standards, if no
design, manufacture, or other change is made to equipment that was certified to UL 471
before the sunsetting date, then the equipment may continue to be produced and used. To
comply with the use condition, once a design change of any kind is made to equipment
that has already been certified under UL 471, the equipment is required to be updated to
UL 60335-2-89 requirements, including labeling.

Several use conditions finalized for these end-use categories are similar to those
finalized for other end-uses. Because of this similarity, EPA discusses the use conditions
that apply to all five end-uses in section II.H of this preamble. In summary, the common
use conditions are: restricting the use of each refrigerant to new equipment that is
specifically designed and clearly marked for that refrigerant; use consistent with
ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions), including testing,
charge sizes, ventilation, usage space requirements, and certain hazard warnings and
markings; and requirements for warning labels and markings on equipment to inform
consumers, technicians, and first responders of potential flammability hazards.
In this final action, EPA is revising the existing listing for R-290 in new standalone units in appendix R to 40 CFR part 82, subpart G, and adding the new listing for R290 in refrigerated food processing and dispensing units in appendix Y to 40 CFR part
82, subpart G. The regulatory text contains revised listing decisions for new stand-alone
units in appendix R, as well as certain other previous listings that EPA is republishing for
purposes of formatting for the Federal Register; EPA is not finalizing substantive
changes to those earlier decisions (e.g., listings for R-290, R-441A, and R-600a in
household refrigerators and freezers and in vending machines).
1. Background on retail food refrigeration
See section II.A.1 of this preamble for background on the retail food refrigeration
end-use and particularly for the stand-alone units and refrigerated food processing and
dispensing equipment end-use categories.
2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes R-290 as being in the A3 Safety Group. See
section II.A.2 of this preamble for further discussion on ASHRAE classifications.
3. What is R-290 and how does it compare to other refrigerants in the
refrigerated food processing and dispensing equipment end-use category?

R-290 is propane and has the formula C3H8 (CAS Reg. No. 74-98-6). Redacted
submissions and supporting documentation for R-290 in retail food refrigeration are
provided in the docket for this final rule (EPA-HQ-OAR-2023-0043) at
https://www.regulations.gov. EPA performed a risk screening assessment to examine the
health and environmental risks of this refrigerant. This risk screen is available in the
docket for this final rule.25
Environmental information: R-290 has an ODP of zero. R-290 has a GWP of
three. R-290 is regulated as a VOC under CAA regulations (40 CFR 51.100(s))
addressing the development of SIPs to attain and maintain the NAAQS. EPA previously
exempted R-290 in retail food refrigerators and freezers (stand-alone units only) from the
venting prohibition under CAA section 608(c)(2), finding that such venting, release, or
disposal does not pose a threat to the environment (79 FR 29682, May 23, 2014).
EPA evaluated potential impacts of R-290 and other HC refrigerants on local air
quality. R-290 is considered a VOC and is not excluded from EPA’s regulatory definition
of VOC (see 40 CFR 51.100(s)) addressing the development of SIPs to attain and
maintain the NAAQS. As described later, EPA estimates that potential emissions of
saturated HC refrigerants, such as R-290 and R-600a (isobutane), would not have a
greater overall negative impact on local air quality than other acceptable substitutes in
this end-use category.26
EPA has conducted multiple analyses of various scenarios to consider the
potential impacts on local air quality if HC refrigerants were used widely.27 The analyses
considered both worst-case and more realistic scenarios. In an analysis supporting the
listings of R-290, R-600a, and the HC blend R-441A in multiple refrigeration and air

ICF, 2023h. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment); Substitute:
Propane (R-290).
26 ICF, 2014a. Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground Level Ozone
Concentrations. February, 2014.
27 Ibid.
conditioning end-uses in SNAP Rule 19 (80 FR 19454, April 10, 2015), the worst-case
scenario assumed that the most reactive HC listed as acceptable as of the time of those
listings (R-600a) was used in all refrigeration and AC uses and that all refrigerant used
was emitted to the atmosphere rather than most being recovered. In that extreme scenario,
the model predicted that the maximum increase in any single 8-hour average ground-level
ozone concentration would be 0.72 parts per billion (ppb) in Los Angeles, which is the
area with the highest level of ozone pollution in the United States. At the time of the
analysis in 2014, 0.72 ppb was less than one percent of the NAAQS, and we stated at the
time that the use of R-600a consistent with the use conditions required in EPA’s
regulations would not result in greater risk to the environment than other alternatives.
Using the level of the current ozone NAAQS of 70 ppb, use of the most reactive saturated
HC, R-600a, with a 100 percent market penetration would just exceed a level that might
raise concerns for EPA. However, considering that R-290 is less reactive than R-600a28
and that R-290 would have a market penetration at least as high as that of R-600a,29 we
still consider use of saturated HC refrigerants not to result in greater overall risk to
human health and the environment.
In a less conservative analysis of potential impacts on ambient ozone levels, EPA
looked at a set of end-uses that would be more likely to use HC refrigerants between now
and 2030, including end-uses where they previously have been listed as acceptable and
where they are acceptable under this final rule. For example, we assumed use of R-290 in
refrigerated food processing and dispensing equipment30 and in end-uses where it is
already listed as acceptable, including retail food refrigeration—stand-alone units,

R-600a has a MIR of 1.34 g O3/g R-600a, while R-290 has a MIR of 0.56 g O3/g R-290. ICF, 2023h, Op.
cit.; Carter, 2010. “Development of the SAPRC-07 Chemical Mechanism and Updated Ozone Reactivity
Scales,” Report to the California Air Resources Board by William P. L. Carter. Revised January 27, 2010.
29 Ibid.
30 In the analysis, refrigerated food processing and dispensing equipment was evaluated under the category
of “small retail food” refrigeration equipment, along with stand-alone units, vending machines, and water
coolers.
vending machines, water coolers, self-contained commercial ice machines, room air
conditioners, and household refrigerators and freezers. We also assumed the use of other
HC refrigerants such as R-600a and R-441A in end-uses where they are listed as
acceptable, such as in retail food refrigeration—stand-alone units, vending machines, and
household refrigerators and freezers. For further information on the specific assumptions,
see the docket for this rulemaking.31 Based on this still conservative but more probable
assessment of refrigerant use, our assessment performed in 2014 found that even if all the
refrigerant in appliances in end-uses addressed in this final rule and in appliances in enduses for which other HCs are listed as acceptable were to be emitted, there would be a
worst-case impact of a 0.15 ppb increase in ozone for a single 8-hour average
concentration in the Los Angeles area, which is the area with the highest level of ozone
pollution in the United States. This value is roughly 0.2 percent of the level of the current
ozone NAAQS of 70 ppb on an 8-hour rolling average over a 6-month period between
April and September of 2030. In the other cities examined in the analysis, Houston and
Atlanta, impacts were smaller (no more than 0.03 and 0.01 ppb for a single 8-hour
average concentration, respectively).32 For areas in the analysis that were not violating
the 2008 ozone NAAQS, the impacts did not cause an exceedance of the 2008 ozone
NAAQS.
EPA also has performed more recent air quality analyses, considering additional
end-uses and HC refrigerants that have been listed acceptable more recently (e.g., R-1150
(ethylene) in very low temperature refrigeration) and using updated models.33 EPA found
that the revised air quality models showed slightly greater impacts compared to our 2014
analyses in all scenarios, but not enough to change our earlier conclusions in 2015 and
ICF, 2014a. Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground Level Ozone
Concentrations. February 2014.
32 Ibid.
33 ICF, 2022. Additional Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground Level
Ozone Concentrations. May 2020. Updated models included VM IO file_v5.1_10.01.19 and CMAQ 5.2.1
with carbon bond 06 (CB06) mechanism, as cited in ICF, 2022.
2016 that use of saturated HCs as refrigerants, including release of R-290, R-600a, and
R-441A during repairing, maintaining, servicing, or disposing of appliances, would not
result in a significant increase in ground-level ozone. Further, there would be no change
in the prior conclusion that use of the saturated HCs R-290, R-600a, and R-441A,
consistent with the SNAP listings, including their use conditions and the final use
conditions in this rule, would not result in greater overall risk to people’s health or the
environment than other alternatives available under SNAP for the same end-use,
refrigerated food processing and dispensing equipment.
Because of the relatively minimal air quality impacts of R-290 if it is released to
the atmosphere from the end-uses where it is listed as acceptable subject to use conditions
and from the refrigerated processing and dispensing equipment end-use category, even in
a worst-case scenario, we conclude that R-290 does not have a greater overall impact on
human health and the environment based on its effects on local air quality than other
refrigerants listed as acceptable in the same end-uses.
Flammability information: R-290 is a higher flammability refrigerant, with an
ASHRAE safety classification of A3. EPA evaluated flammability risk by evaluating
reasonable worst-case and more typical, yet conservative, scenarios to model the effects
of releases of R-290 in retail food refrigeration. This refrigerant is not expected to present
a flammability concern provided the use conditions are followed. The use conditions
provide additional safety measures and labeling requirements (e.g., visible warning
statement and red coloring on the pipes, hoses, and devices which contain refrigerant)
that make equipment owners, consumers, fire marshals, and emergency first responders
aware of the presence of a flammability hazard.
Toxicity and exposure data: R-290 has an ASHRAE toxicity classification of A
(lower toxicity). Potential health effects of exposure to this refrigerant include drowsiness
or dizziness. The refrigerant may also irritate the skin or eyes or cause frostbite. This

refrigerant could cause asphyxiation if air is displaced by vapors in a confined space.
These potential health effects are common to many refrigerants.
OSHA has established a PEL of 1,000 ppm as an 8-hr TWA for R-290. EPA
anticipates that users will be able to meet OSHA’s PEL and address potential health risks
by following requirements and recommendations in the manufacturers’ SDSs, the final
use conditions (including compliance with UL 60335-2-89), adherence to ASHRAE 152022, and other safety precautions common to the refrigeration and AC industry.
Comparison to other substitutes in the refrigerated food processing and
dispensing end-use category: R-290 has an ODP of zero, comparable to or lower than
some of the acceptable substitutes in new refrigerated food processing and dispensing
equipment, such as CO2, R-450A, and R-513A, with ODPs of zero.
R-290’s GWP of three is comparable to that of other acceptable substitutes for
new refrigerated food processing and dispensing equipment, including CO2, with a GWP
of one. The GWP of R-290 is lower than some of the acceptable substitutes for new
refrigerated food processing and dispensing equipment, such as R-450A, R-513A, R134a, and R-407H, with GWPs of approximately 600, 630, 1,430, and 1,500,
respectively.
EPA’s risk screen for R-290 in retail food refrigeration,34 including refrigerated
food processing and dispensing equipment, found that R-290 can be used without
exceeding its PEL of 1,000 ppm (8-hr TWA); thus, the toxicity risks of R-290 are
comparable to those of other acceptable substitutes in the refrigerated food processing
and dispensing equipment end-use category, which also are used without exceeding their
workplace exposure limits.
Although the flammability of R-290 may be greater than that of other available
refrigerants with an ASHRAE 1, 2, or 2L flammability classification in the same end-use,

ICF, 2023h. Op. cit.

we found its flammability risk to be comparable to those of other acceptable substitutes,
even under worst-case assumptions in this end-use category when following the final use
conditions.35 We note that flammability risk can be minimized by use consistent with
industry standards such as UL 60335-2-89–which applies under the use conditions–and
ASHRAE 15-2022–which also applies under the use conditions–as well as
recommendations in the manufacturers’ SDS and other safety precautions common in the
refrigeration and air conditioning industry. EPA is finalizing use conditions that reduce
the flammability risk associated with this alternative so that it will not pose greater
overall risk to human health and the environment than other acceptable substitutes in this
end-use category.
Based on the results of these analyses, EPA is listing R-290 as acceptable, subject
to use conditions, in refrigerated food processing and dispensing equipment. R-290 has a
GWP of three, lower than that of most other available alternatives for the same end-use
category with similarly low toxicity. R-290 provides an additional lower-GWP option for
situations where other refrigerants with lower GWPs are not viable, such as where
equipment using CO2 may not be able to meet DOE’s energy conservation standards. To
provide an additional, lower-GWP option with lower overall risk to human health and the
environment, EPA is listing R-290 as acceptable, subject to use conditions, for use in
refrigerated food processing and dispensing equipment.
4. Why is EPA finalizing these specific use conditions for refrigerated food
processing and dispensing equipment?
For refrigerated food processing and dispensing equipment, EPA is requiring
adherence to UL 60335-2-89 for equipment falling under the scope of that standard.
Several of the use conditions for refrigerated food processing and dispensing equipment
are common to those finalized for R-290 in the commercial ice machine end-use as

ICF, 2023h. Op. cit.

discussed in section II.D of this preamble. Other use conditions are common to all
refrigerants and all five end-uses in this final rule. Because of this similarity, EPA
discusses the use conditions that apply to all five end-uses in section II.H of this
preamble. In summary, the common use conditions for all five end-uses are: restricting
the use of each refrigerant to new equipment that is specifically designed and clearly
marked for that refrigerant; use consistent with ASHRAE 15-2022 and with UL 60335-289 (with certain exceptions), including testing, charge sizes, ventilation, usage space
requirements, and certain hazard warnings and markings; and requirements for warning
labels and markings on equipment to inform consumers, technicians, and first responders
of potential flammability hazards.
5. How does the listing for R-290 in refrigerated food processing and
dispensing equipment relate to regulations implementing the venting prohibition
under CAA section 608?
In section II.I of this preamble EPA is finalizing an exemption for R-290 used as a
refrigerant in refrigerated food processing and dispensing equipment from the prohibition
under CAA section 608(c)(2) on knowingly venting or otherwise knowingly releasing or
disposing of any substitute refrigerant in the course of maintaining, servicing, repairing,
or disposing of an appliance or IPR.
6. What existing use conditions apply to this refrigerant in the stand-alone
units end-use category?
EPA previously listed R-290 acceptable, subject to use conditions, in new standalone units in SNAP Rule 17 (76 FR 78832, December 20, 2011). Those requirements are
codified in appendix R to 40 CFR part 82, subpart G. EPA provided information on the
potential environmental and health risks of R-290 and the various refrigerants available at
that time for use in this end-use category. EPA's previous risk screen for this refrigerant
in this end-use category, based on the use conditions in that rule, is available in the

docket for that previous rulemaking (EPA-HQ-OAR-2009-0286).
R-290 has an ASHRAE classification of A3, indicating that it has low toxicity and
higher flammability. In the presence of an ignition source (e.g., static electricity, a spark
resulting from a closing door, or a cigarette), an explosion or a fire could occur if the
concentration of R-290 were to exceed the LFL of 21,000 ppm (2.1 percent) by volume.
The use conditions established in the SNAP Rule 17 for R-290 in new stand-alone
units addressed safe use of this flammable refrigerant based on information available at
that time and included the following: incorporation by reference of Supplement SB to the
10th edition (November 24, 2010) of UL 471 “Commercial Refrigerators and Freezers;”
refrigerant charge size limits based on cooling capacity and type of equipment; and
requirements for markings and warning labels on equipment using the refrigerant to
inform consumers, technicians, and first responders of potential flammability hazards.
EPA explained in that rulemaking that without appropriate use conditions, the
flammability risk posed by this refrigerant could be higher than non-flammable
refrigerants because individuals may not be aware that their actions could potentially
cause a fire, and because the refrigerant could be used in existing equipment that has not
been designed specifically to minimize flammability risks. Our assessment and listing
decisions in SNAP Rule 17 (76 FR 78832, December 20, 2011) found that with the use
conditions, the overall risk of R-290, including the risk due to flammability, was not
greater in the stand-alone units end-use than other substitutes that are currently or
potentially available for that same end-use.
7. What updates to existing use conditions for stand-alone units is EPA
finalizing?
EPA is finalizing the proposed use conditions that apply to R-290 in new standalone units manufactured on or after the effective date of this final rule. The updated use
conditions finalized for use of R-290 in stand-alone units are common to those finalized

for the commercial ice machine end-use in section II.D of this preamble, and others are
common to all five end-uses in this final rule. Because of this similarity, EPA discusses
the use conditions that apply to all five end-uses in section II.H of this preamble. For R290 in stand-alone units, these use conditions in sections II.D and II.H of this preamble
are the only revised use conditions EPA is finalizing—i.e., there are no use conditions
pertaining to refrigerant charge capacity or specific applications within stand-alone units.
In summary, with the updates finalized for the use conditions for stand-alone units, the
common use conditions are: restricting the use of each refrigerant to new equipment that
is specifically designed and clearly marked for that refrigerant; use consistent with
ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions), including testing,
charge sizes, ventilation, usage space requirements, and certain hazard warnings and
markings; and requirements for warning labels and markings on equipment to inform
consumers, technicians, and first responders of potential flammability hazards.
EPA is finalizing the use conditions in this action, which apply to new stand-alone
units on or after the effective date of this final rule. This final rule does not apply to nor
affect equipment manufactured before the effective date of this action. The final
regulatory text presents these different requirements as numbered listings in separate
table rows, where the end-use and the effective time period during which the equipment
is manufactured are in the left-most column, with the heading “End-use”; the specific
requirements are listed as use conditions in the fourth column, with the heading “Use
Conditions.” Under SNAP, EPA views equipment to be manufactured at the date upon
which the appliance’s refrigerant circuit is complete, the appliance can function, the
appliance holds a full refrigerant charge, and the appliance is ready for use for its
intended purposes. For stand-alone units (and most refrigerated food processing and
dispensing equipment), this occurs at the factory. New stand-alone units manufactured
between February 21, 2012, and the effective date of the final rule that use R-290 are

required to meet the use conditions in SNAP Rule 17 (which took effect February 21,
2012) and as listed in appendix R to 40 CFR part 82, subpart G (in listing 2), including
the use condition incorporating by reference Supplement SB to the 10th edition of UL
471. Such products are permitted to be warehoused and sold through normal channels,
even if they are sold after the effective date of this final rule. Stand-alone units using R290 manufactured on or after the effective date of this final rule are required to meet the
use conditions finalized and listed in the revisions to appendix R. Those use conditions
allow manufacturers of new stand-alone units using R-290 to follow either UL 471 or UL
60335-2-89 from the effective date of this final rule and through September 29, 2024,
which is the date when UL is sunsetting UL 471. On and after September 30, 2024, new
stand-alone units using R-290 for any new equipment designs or models must meet UL
60335-2-89; for an unchanged model or design that was already listed by UL—that is,
certified to meet the requirements of UL 471—the equipment can continue to be
manufactured according to that standard’s requirements.
EPA is finalizing use conditions allowing all new stand-alone units using R-290
to be manufactured consistent with Supplement SB of UL 471, up to and including
September 29, 2024. Therefore, during the time between the effective date of this final
rule and September 29, 2024, manufacturers may follow either UL 471, 10th edition or
UL 60335-2-89, 2nd edition, depending on which standard the equipment was designed
to. This transition date was in this rule’s proposal in order to align with the industry
standard sunsetting date for UL 471. It is EPA’s understanding that since proposal, UL
has discussed updating its effective date when UL 60335-2-89 replaces UL 471 to reflect
a later continuing certification date. EPA is allowing manufacturers to adhere to either
standard for this limited time because the Agency recognizes that manufacturers may
need time to make necessary changes including to their product labels. The period during
which manufacturers may follow either standard should provide sufficient time for

manufacturers to transition from UL 471 to UL 60335-2-89 while designing and testing
new models and designs. Beginning September 30, 2024, for the purposes of the SNAP
program, newly manufactured stand-alone units of new models and designs using R-290
must meet the requirements of UL 60335-2-89. Newly manufactured stand-alone units of
existing models and designs that are certified (e.g., UL-listed) using R-290 that remain
unchanged other than cosmetic changes (e.g., color changes) and that meet Supplement
SB of UL 471 prior to September 30, 2024, may continue to meet those requirements
after that date. In addition, we are requiring manufacturers to follow the set of use
conditions that correspond with a specific UL standard (e.g., we are including text in the
revisions to appendix R stating that when an entity is using UL 471, it is to follow all use
conditions in listing 2 and when using UL 60335-2-89, it is to follow all use conditions in
listing 4 in the final revisions to appendix R). See section II.H.1 of this preamble for
further discussion on the requirements of UL 60335-2-89, 2nd edition, which EPA is
incorporating by reference.
EPA also notes that we are continuing to apply without revision two existing use
conditions, nor did we take comment on those two existing use conditions. The use
conditions finalized in this rule that restrict the use of R-290 to new equipment
specifically designed for this refrigerant, and that require red-colored markings on service
ports, pipes, hoses, and other devices through which the refrigerant is serviced, repeat the
existing use conditions for R-290 in new stand-alone units.
8. How do the new use conditions for R-290 in stand-alone units differ
from the existing ones and why is EPA changing the use conditions?
The revised use conditions EPA is finalizing for R-290 in stand-alone units are
the same as or similar to the ones that exist today in appendix R to 40 CFR part 82,
subpart G, for R-290 in this end-use category. The final requirements that R-290 must be
used in new equipment only, and that new stand-alone units must include red markings at

service ports, pipes, hoses, and other devices through which the refrigerant is serviced,
are repeated in this final listing. The revised use conditions concern incorporating by
reference the most recent U.S. national industry safety standard and updated labeling
requirements consistent with that new standard. Stand-alone units using R-290
manufactured before the effective date of this final rule are not affected by the revised
use conditions.
Warning labels are required under EPA’s use restrictions for R-290 in stand-alone
units, and EPA is continuing to require them, although with some specific language
changes. The finalized warning labels are similar to those already established as use
conditions for the use of R-290 in stand-alone units. Using a common set of labels,
similar to those from UL 60335-2-89, will aid in compliance and reduce burden for the
industry, especially for a manufacturer that uses more than one refrigerant. EPA is
finalizing that the labels must be provided in letters no less than 6.4 millimeter (¼ inch)
high and must be permanent, which is identical to the existing requirement for R-290 in
stand-alone units.
EPA is incorporating by reference a newer industry standard in the use conditions,
including use of UL 60335-2-89, 2nd edition for equipment newly designed and
manufactured on or after the effective date of this final rule instead of continuing to
require Supplement SB of the 10th edition of UL 471. UL 60335-2-89 was developed in
an open and consensus-based approach, with the assistance of experts in the refrigeration
and AC industry as well as experts involved in assessing the safety of products. The
revision cycle for the 2nd edition, including final recirculation, concluded with its
publication on October 27, 2021. UL 60335-2-89 replaces the previously published
version of several standards, including UL 471, which had already been published as a
10th edition by that time. EPA was aware of the continuing progress of UL standards to
address flammable refrigerants. In SNAP Rule 23 (86 FR 24444, May 6, 2021), which

listed a number of A2L refrigerants for use in the residential and light commercial AC
and heat pumps end-use, we stated, “EPA understands that the standard we relied on in
[SNAP] Rule 19 might ‘sunset’ in the future. Therefore, we will continue to evaluate the
market for the equipment addressed in that rule, including R-290 in stand-alone units, and
whether to establish new or revised use conditions that reference UL 60335-2-89.”
Today, we are finalizing such a change knowing that the standard to which such
equipment is UL-listed will transition from UL 471 to the most recent standard, UL
60335-2-89, for newly designed and manufactured equipment as of September 30, 2024.
To allow time for manufacturers of stand-alone units to transition between the
existing use condition using the 10th edition of UL 471 and the new use condition using
UL 60335-2-89, EPA is allowing R-290 to be used in stand-alone units manufactured
either following UL 471 or UL 60335-2-89 during a transition period. That transition
period begins on the effective date of this final rule, [INSERT DATE 30 DAYS AFTER
DATE OF PUBLICATION IN THE FEDERAL REGISTER], and lasts through
September 29, 2024. It is EPA’s understanding that UL intends to sunset UL 471 on
September 29, 2024, and EPA is coordinating with that sunset date. Further, based on
public comments, EPA understands that UL allows newly manufactured equipment that
remains unchanged from its previous UL-listed (certified) design or model to continue to
follow an earlier standard such as UL 471 because the manufacturer has made no
changes. EPA intends to follow this practice, as well, in this final rule. Beginning
September 30, 2024, the use condition allows R-290 to be used in new stand-alone units
that follow UL 60335-2-89, or for newly manufactured stand-alone units that are
unchanged from the model or design previously UL-listed as meeting UL 471 10th
edition. In addition, manufacturers must follow the set of use conditions that correspond
with a specific UL standard (i.e., when using UL 471, follow all use conditions in listing
4 and when using UL 60335-2-89, follow all use conditions in listing 6 in the final

revisions to appendix R).
Another revision to the use conditions is the limit on charge sizes. The existing
use conditions from SNAP Rule 17 require the charge sizes to be calculated consistent
with UL 471, with a maximum charge of 150 g allowed. The final revised use conditions
for equipment newly designed and manufactured on or after the effective date of this final
rule allow charge sizes calculated based on UL 60335-2-89, which allows charges of up
to roughly 500 g of R-290 for open stand-alone units, or roughly 300 g for those with
doors and drawers. These changes allow the use of R-290 in larger equipment than
previously and provide more options for industry, while mitigating flammability or
exposure risk and maintaining safety within a comparative risk framework.
Because of the differences between UL 471 and UL 60335-2-89, EPA performed
a new risk screen for R-290 as a refrigerant in retail food refrigeration equipment,
including stand-alone units.36 In this risk screen, EPA adjusted charge sizes to be
consistent with the larger charge sizes of roughly 300 g and 500 g allowed for R-290
under UL 60335-2-89. The risk screen also considered the impact of mitigation methods
such as valves that would restrict the amount of refrigerant that could be released, with a
limit on “releasable charge.” The updated risk screen found that concentrations of R-290
still would not exceed the LFL when used according to the new use condition with
releasable charge and larger charge sizes and consistent with UL 60335-2-89, and thus
the new use conditions also address potential flammability risks of using R-290.37 In
addition, the risk screen modeled the reasonable worst-case scenario of short-term
exposure (15-minute TWA) due to a catastrophic release of the charge. Under this highly
conservative scenario, the worst-case exposure of 5,770 ppm was still significantly lower
than the Acute Toxicity Exposure Limit (ATEL) of 50,000 ppm.38 According to

ICF, 2023h. Op. cit.
Ibid.
38 The source of the ATEL is ASHRAE 34-2022, as cited in ICF, 2023h. Op cit.
36
ASHRAE 34, R-290 is listed under safety group A3 with an ATEL of 50,000 ppm.
ASHRAE 34 ATELs are intended to reduce the risks of acute toxicity, asphyxiation, and
flammability hazards in normally occupied, enclosed spaces during refrigerant use and
protect end-users from the potential dangers of a catastrophic leak from a refrigeration
unit. For further information, see the risk screen39 for R-290 in the docket for this
rulemaking.
9. What additional information is EPA including in these listings?
EPA is providing additional information related to this final listing for R-290 in
new refrigerated food processing and dispensing equipment and the final listing for R290 in new stand-alone units. Since this additional information is not part of the
regulatory decision under SNAP, these statements are not binding for use of the
refrigerant under the SNAP program. See section II.H.2 of this preamble for further
discussion on what additional information EPA is including in these listings. This
additional information is similar to, but not identical with, the additional information in
the listing for R-290 in stand-alone units in SNAP Rule 17, which included additional
information such as applicable OSHA requirements, need for proper ventilation, use of
personal protective equipment, fire extinguishers to keep nearby, use of spark-proof tools
and recovery equipment designed for flammable refrigerants, and suggestions for
technician training. EPA is finalizing additional information consistent with that included
in the final listings for other refrigerants in stand-alone units in this rule and consistent
with that included in the listings for R-290 as acceptable, subject to use conditions, in
stand-alone units in Rule 17, with additional information such as recommendations for
actions to take in case of an accidental release, additional recommended practices for
technicians, DOT requirements for transport of flammable gases, and statement that
disposed flammable refrigerant is likely to be hazardous waste under RCRA. While the

ICF, 2023h. Op. cit.

items listed are not legally binding under the SNAP program, EPA encourages users of
substitutes to apply all statements in the “Further Information” column in their use of
these refrigerants.
10. How is EPA responding to comments on listing R-290 in refrigerated
food processing and dispensing equipment and updating the use conditions for R290 in stand-alone units?
Several commenters provided input on listing R-290 as a substitute.
Comment: Two commenters referenced charge size considerations for R-290 and
asked that EPA align the final rule with industry standards to reduce confusion. One
commenter asked EPA to conform its description of R-290 charge sizes to those allowed
under UL 60335-2-89 and ASHRAE 15: 13 times the LFL for open appliances (494 g),
eight times the LFL for closed appliances with doors and drawers (304 g), and 3 times the
LFL in public corridors and lobbies (114 g). To avoid confusion, they cautioned EPA to
avoid noting that a charge limit of 500 g of R-290 is permitted. The same commenter
noted that larger charge sizes of R-290 are only permitted for products listed to UL
60335-2-89, and not UL 471. A different commenter added that the UL 60335-2-89
standard for stand-alone retail food refrigeration equipment with R-290 is thorough and
sufficient. They mentioned that conversion of self-contained refrigeration equipment
using R-290 is currently constrained by the use restrictions for stand-alone retail food
refrigeration (150 grams or less in UL 471). They added that work remains to properly
and safely convert products that require larger charges of R-290 to supply the cooling
capacity needed. Another commenter requested that EPA allow larger charges of R-290
in the high side of cascade systems or secondary systems in all applications. They stated
that R-290 can be paired with carbon dioxide to make an energy efficient system in
warmer climates. They added that the International Institute of Ammonia Refrigeration
(IIAR) is developing a standard specifically for the use of R-290.

Response: EPA agrees with the commenters concerning the description of charge
sizes for R-290 and the related requirements of UL 60335-2-89 and ASHRAE 15.
Specifically, UL 60335-2-89 limits charge sizes for R-290 to 13 times the LFL for open
appliances (494 g), eight times the LFL for closed appliances with doors and drawers
(304 g), and ASHRAE 15-2022 limits charges to 3 times the LFL in public corridors and
lobbies (114 g). As noted by the commenters, the charge size limit for R-290 is 150 g for
equipment following UL 471. EPA did not propose to list R-290 as acceptable, subject to
use conditions, for the high side of cascade systems or secondary loop systems in all
applications and did not receive information in a submission for such uses of R-290; thus,
EPA has not performed necessary analysis to make a listing decision nor provided an
opportunity for comment on that analysis. EPA also notes that the current edition (2nd
edition) of UL 60335-2-89 only allows use of A3 (higher flammability) refrigerants in
self-contained equipment, which applies to stand-alone units and to some refrigerated
food processing and dispensing equipment, not to supermarket systems or remote
condensing units. In response to the comments regarding IIAR standard development,
EPA would first need to review a final standard and propose it as a use condition before
requiring it in a final listing; thus, this comment is beyond the scope of this rulemaking.
EPA will continue to monitor development of and changes to relevant standards, and the
Agency may consider whether any additions to or revisions to the SNAP program
regulations should be proposed at a future date.
Comment: One commenter stated that expanding the use of R-290, with a low
GWP, will help minimize harmful climate impacts of refrigerant emissions while
maintaining safe systems.
Response: EPA agrees in general that allowing greater use of R-290 would allow
for lower climate impacts, and so long as R-290 is used according to the use conditions in

this final rule, we expect it will be used as safely as other available substitutes for the
same uses.
C. Commercial Ice Machines—Listing of HFC-32, HFO-1234yf, R-454A, R-454B,
R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in
new commercial ice machines
This final rule lists HFC-32, HFO-1234yf, and the refrigerant blends R-454A, R454B, R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions,
for use in new commercial ice machines. The listings for refrigerants HFC-32, R-454A,
and R-454B are being finalized in this rule only for larger equipment—specifically,
remote commercial ice machines, self-contained batch-type commercial ice machines
with a harvest rate greater than 1,000 lb ice per 24 hours, and self-contained continuoustype commercial ice machines with a harvest rate above 1,200 lb ice per 24 hours; EPA is
not finalizing listings for those three refrigerants for smaller commercial ice machines at
this time.
Several use conditions finalized for commercial ice machines are common to
those finalized for other end-uses. Because of this similarity, EPA discusses the use
conditions that apply to all five end-uses in section II.H of this preamble. For commercial
ice machines, those are the only use conditions EPA is finalizing. In summary, the
common use conditions are: restricting the use of each refrigerant to new equipment that
is specifically designed and clearly marked for that refrigerant; use consistent with
ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions), including testing,
charge sizes, ventilation, usage space requirements, and certain hazard warnings and
markings; and requirements for warning labels and markings on equipment to inform
consumers, technicians, and first responders of potential flammability hazards.
In this final action, EPA is revising the existing listing for R-290 in new selfcontained commercial ice machines in appendix V to 40 CFR part 82, subpart G. The

regulatory text contains listing decisions for the commercial ice machines end-use, as
well as certain other previous listings that EPA is republishing for purposes of formatting
for the Federal Register; EPA is not finalizing substantive changes to those earlier
decisions, e.g., listings for R-290 in new water coolers and in new very low temperature
refrigeration equipment.
1. Background on commercial ice machines
Commercial ice machines are used in commercial establishments (e.g., hotels,
restaurants, convenience stores) to produce ice for consumer use. Commercial ice
machines40 are another subset of commercial refrigeration and are considered a separate
end-use within the SNAP program from retail food refrigeration due to differences in
where such equipment is placed and the additional mechanical and electronic components
required to make and dispense ice. Ice machines produce ice in various sizes and shapes,
and with different retrieval mechanisms (e.g., dispensers or self-retrieval from bins).
Many commercial ice machines are self-contained units, while some have the condenser
separated from the portion of the machine making the ice and have refrigerated lines
running between the two (also known as remote condensing equipment). The listings
described in section II.C.4 of this preamble apply both to larger self-contained
commercial ice machines and to remote condensing commercial ice machines.
Commercial ice machines fall under the scope of UL 60335-2-89, “Household and
Similar Electrical Appliances - Safety - Part 2-89: Requirements for Commercial
Refrigerating Appliances and Ice-Makers with an Incorporated or Remote Refrigerant
Unit or Motor-Compressor.”
Commercial ice machines can also be divided between batch-type machines (e.g.,
providing cubed ice) and continuous-type machines (e.g., providing flaked ice). Batch-

Industry standards for this type of equipment, e.g., UL 563 and UL 60335-2-89, use the terms “ice
maker” or “ice-maker” rather than commercial ice machines. The terms may be used interchangeably and
refer to the same equipment.
type (also called cube type) ice machines harvest ice with alternating freezing and
harvesting periods. Batch-type commercial ice machines can be used in a variety of
applications but are generally used to generate ice for use in beverages. Batch-type
commercial ice machines are often employed in hotels, hospitals, and restaurants where
beverages are served. Continuous-type ice makers produce ice through a continuous
freeze and harvest process and include flake and nugget ice machines. Flake ice is used
primarily in food displays, such as seafood grocery store displays or salad bars, whereas
nugget ice (also known as chewable ice) is primarily used in beverage applications such
as smoothies and blended cocktails. DOE sets energy conservation standards for
commercial ice machines and distinguishes these based in part on their harvest rate,41
defined as “as the amount of ice (at 32 degrees F) in pounds produced per 24 hours.’’ 10
CFR 431.132.
R–404A has commonly been used in remote condensing commercial ice
machines, while both R–404A and R–410A have been commonly used in self-contained
commercial ice machines. Recently, there has been the introduction of smaller selfcontained commercial ice machines that use R-290.
2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes the refrigerants for commercial ice machines in
this section as being in the A2L Safety Group. See section II.A.2 of this preamble for
further discussion on ASHRAE classifications of these refrigerants.
3. What are HFC-32, HFO-1234yf, R-454A, R-454B, R-454C, R-455A, R457A, and R-516A and how do they compare to other refrigerants in the same
end-use?
See section II.A.3 of this preamble for further discussion on the identity,

For purposes of this rule, the harvest rate shall be determined in accordance with 10 CFR 431.134.

environmental, flammability, toxicity, and exposure information for HFO-1234yf, R454A, R-454C, R-455A, R-457A, and R-516A.42
HFC-32 is also known as R-32 or difluoromethane (CAS Reg. No. 75-10-5). R454B, also known by the trade names “Opteon™ XL 41” and “Puron Advance™,” is a
blend consisting of 68.9 percent HFC-32 and 31.1 percent HFO-1234yf. Redacted
submissions and supporting documentation for HFC-32, HFO-1234yf, and the refrigerant
blends are provided in the docket for this rule (EPA-HQ-OAR-2023-0043) at
https://www.regulations.gov. EPA performed a risk screening assessment to examine the
health and environmental risks of each of these refrigerants. These risk screens are
available in the docket for this rule.43,44,45,46,47,48,49,50
Environmental information: HFC-32 and R-454B, as well as the other refrigerants
being listed in this end-use, have ODPs of zero.
HFC-32 has a GWP of 675. If the GWPs for the components of R-454B, HFC-32
and HFO-1234yf (GWP of one), are weighted by mass percentage, then the blend R454B has a GWP of about 465.

EPA previously listed HFO-1234yf as acceptable, subject to use conditions, in motor vehicle AC in lightduty vehicles (74 FR 53445, October 19, 2009), in heavy-duty pickup trucks and complete heavy-duty vans
(81 FR 86778, December 1, 2016) and in nonroad vehicles and service fittings for small refrigerant cans
(87 FR 26276, May 4, 2022). EPA previously listed R-454A, R-454B, R-454C, and R-457A as acceptable,
subject to use conditions, as substitutes in residential and light commercial AC and heat pumps (86 FR
24444, May 6, 2021). EPA previously listed HFC-32 as acceptable, subject to use conditions, in selfcontained room air conditioners (80 FR 19453, April 10, 2015) and listed HFC-32 as acceptable, subject to
use conditions, in the remaining types of residential and light commercial air conditioning and heat pumps.
43 ICF, 2024i. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: HFC32.
44 ICF, 2024j. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: HFO1234yf.
45 ICF, 2024k. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R454A (Opteon® XL40).
46 ICF, 2024l. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R454B.
47 ICF, 2024m. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R454C (Opteonâ„¢ XL20).
48 ICF, 2024n. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R455A (Solstice® L40X).
49 ICF, 2024o. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R457A (Forane® 457A).
50 ICF, 2024p. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: R516A (Forane® 516A).
Both of the components of R-454B, HFC-32 and HFO-1234yf, are excluded from
EPA’s regulatory definition of VOC (see 40 CFR 51.100(s)) for the purpose of
addressing the development of SIPs to attain and maintain the NAAQS.
Under section 608(c)(2) of the CAA and EPA’s regulations at 40 CFR
82.154(a)(1), it is unlawful for any person, in the course of maintaining, servicing,
repairing, or disposing of an appliance or IPR, to knowingly vent or otherwise knowingly
release or dispose of any substitute substance for a class I or class II substance used as a
refrigerant in such appliance (or IPR) in a manner which permits such substance to enter
the environment. EPA has established certain limited exemptions to this venting
prohibition, as listed in 40 CFR 82.154(a)(1), but none of those exemptions apply to
HFC-32 or R-454B.
Flammability information: HFC-32 and R-454B are both classified as 2L
refrigerants under ASHRAE Standards reflecting that these compounds are flammable
but have lower burning velocity than compounds listed as 2 or 3 under the ASHRAE
standard. EPA evaluated flammability risk by evaluating reasonable worst-case and more
typical, yet conservative, scenarios to model the effects of releases of HFC-32 and R454B, respectively, in the listed end-uses. These refrigerants are not expected to present a
flammability concern provided the use conditions are followed. The use conditions
provide additional safety measures and labeling requirements (e.g., visible warning
statement and red coloring on the pipes, hoses, and devices which contain refrigerant)
that make equipment owners, consumers, fire marshals, and emergency first responders
aware of the presence of a flammability hazard.
Toxicity and exposure data: HFC-32 and R-454B have an ASHRAE toxicity
classification of A. Potential health effects of exposure to these refrigerants include
drowsiness or dizziness. The refrigerants may also irritate the skin or eyes or cause
frostbite. At sufficiently high concentrations, the refrigerants may cause irregular

heartbeat. The refrigerants could cause asphyxiation if air is displaced by vapors in a
confined space. These potential health effects are common to many refrigerants.
AIHA has established a WEEL of 1,000 ppm (8-hr TWA) for HFC-32 and a
WEEL of 500 ppm as an 8-hr TWA for HFO-1234yf, the components of R-454B. The
manufacturer of R-454B recommends an AEL for the workplace of 854 ppm on an 8-hr
TWA for this blend, as does ASHRAE 34-2022. EPA anticipates that users will be able to
meet the AIHA WEELs and the manufacturer’s AEL and address potential health risks
by following requirements and recommendations in the manufacturers’ SDS, the final use
conditions (including adherence to UL 60335-2-89 and ASHRAE Standard 15), and other
safety precautions common to the refrigeration and AC industry.
Comparison to other substitutes in this end-use: HFC-32, HFO-1234yf, and the
refrigerant blends R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A all have an
ODP of zero, comparable to or lower than some of the acceptable substitutes in new
commercial ice machines, such as HFC-134a, R-410A, and R-513A, with ODPs of zero.
HFO-1234yf has a GWP of one, comparable to that of R-290 and ammonia with
GWPs of three and zero. R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A have
GWPs ranging from 140 to 465, higher than some of the acceptable substitutes for new
commercial ice machines and lower than those of other substitutes such as R-450A and
R-513A, with GWPs of about 600 and 630. HFC-32 has a GWP of 675, higher than some
of the acceptable substitutes including R-290, R-450A, and R-513A; however, the GWP
of HFC-32 is lower than those of R-410A and R-404A, with GWPs of approximately
2,090 to 3,920, which are refrigerants that have typically been employed in larger
systems. Our evaluation is that the characteristics of HFC-32, R-454A, and R-454B meet
the technical needs of larger commercial ice machines, providing larger charge sizes,
greater capacity and no glide, allowing for even formation of ice, while lower-GWP
alternatives do not. For instance, R-513A and R-450A have lower capacity than HFC-32,

and R-290 is restricted to smaller charge sizes (see section II.D of this preamble for
further information). Remote appliances using A2L refrigerants, including remote
condensers, may be either self-contained or field erected and may be factory or field
charged.
Information regarding the toxicity of other available alternatives is provided in the
previous listing decisions for new commercial ice machines
(https://www.epa.gov/snap/substitutes-commercial-ice-machines). Toxicity risks of use,
determined by the likelihood of exceeding the exposure limit of HFC-32, HFO-1234yf,
and the refrigerant blends in these end-uses are evaluated in the risk screens referenced
previously. The toxicity risks of using HFC-32, HFO-1234yf, and the refrigerant blends
in new commercial ice machines are comparable to or lower than toxicity risks of other
available substitutes in the same end-use. Toxicity risks of the listed refrigerants can be
mitigated by use consistent with UL 60335-2-89 and ASHRAE 15-2022–which are
required by our final use conditions–and other industry standards; recommendations in
the manufacturers’ SDS; and other safety precautions common in the refrigeration and
AC industry.
The flammability risks of HFC-32, HFO-1234yf, and the refrigerant blends R454A, R-454B, R-454C, R-455A, R-457A, and R-516A in the new commercial ice
machine end-use, determined by the likelihood of exceeding their respective LFLs, are
evaluated in the risk screens referenced previously in this section. While these
refrigerants pose greater flammability risk than other available, non-flammable
substitutes in the new commercial ice machines end-use, this risk can be mitigated by use
consistent with ASHRAE 15-2022 and UL 60335-2-89, required as use conditions in this
rule, as well as recommendations in the manufacturers’ SDS and other safety precautions
common in the refrigeration and AC industry. EPA is requiring use conditions to reduce
the potential risk associated with the flammability of these alternatives so that they will

not pose greater overall risk to human health and the environment than other acceptable
substitutes in the new commercial ice machines end-use.
In addition, the listed refrigerants have lower GWPs than most other available
alternatives for new commercial ice machines. The listing of these refrigerants provides
additional lower-GWP options for situations where other refrigerants with lower GWPs
are not viable, such as for use of HCs in systems with remote compressors or equipment
requiring larger charge sizes, where equipment using CO2 may not be able to meet energy
conservation standards from the DOE, or where a refrigerant must have minimal glide to
ensure consistent freezing while manufacturing ice. Given the wide range of applications
and exacting performance requirements for commercial ice machines, not all refrigerants
listed as acceptable under SNAP will be suitable for the range of equipment in new
commercial ice machines. To provide additional options to ensure the availability of
refrigerants with lower GWPs for the full range of new commercial ice machines and,
therefore, lower overall risk to human health and the environment, EPA is listing HFO1234yf and the refrigerant blends R-454C, R-455A, R-457A, and R-516A as acceptable,
subject to use conditions, for use in all types of new commercial ice machines. Further,
EPA is listing HFC-32, R-454A, and R-454B as acceptable, subject to use conditions, in
larger commercial ice machines: specifically, remote commercial ice machines, selfcontained batch-type commercial ice machines with a harvest rate greater than 1,000 lb
ice per 24 hours, and self-contained continuous-type commercial ice machines with a
harvest rate above 1,200 lb ice per 24 hours. EPA is not finalizing listings for those three
refrigerants for smaller self-contained commercial ice machines at this time, as lowerGWP refrigerants, such as R-290, perform adequately. Further, EPA notes that in the
final Technology Transitions Rule under the AIM Act, smaller self-contained commercial
ice machines, namely, batch-type self-contained units with a harvest rate at or below
1,000 lb ice per 24 hours and continuous-type self-contained units with a harvest rate at

or below 1,200 lb ice per 24 hours, are restricted to using refrigerants with a GWP less
than 150.
4. Why is EPA finalizing these specific use conditions?
The use conditions identified in these final listings are explained in section II.H.1
of this preamble in greater detail.
5. What additional information is EPA including in these listings?
EPA is providing additional information related to these listings. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the substitute under the SNAP program. While the
items listed are not legally binding under the SNAP program, EPA encourages users of
substitutes to apply all statements in the “Further Information” column in their use of
these refrigerants. See section II.H.2 of this preamble for further discussion on what
additional information EPA is including in these listings.
6. How is EPA responding to comments on commercial ice machines?
Comment: One commenter recommended that EPA restrict acceptable substitutes
in commercial ice machines to those below a 150 GWP limit. The reason for this
commenter’s request was to align with GWP limits in the proposed Technology
Transition rulemaking, which, as proposed, would set a January 1, 2025, compliance date
limiting refrigerants over a GWP of 150 for self-contained commercial ice machines with
a charge of 500 grams or less. They noted the proposed SNAP Rule 26’s inclusion of
HFC-32, R-454A, and R-454B for use in commercial ice machines would conflict with
the proposed Technology Transitions Rule, which would restrict the GWP of refrigerants
below 150 in self-contained commercial ice machines with a charge size less than 500 g.
The commenter pointed out that low-GWP refrigerants like carbon dioxide and R-717
would still be available for use in this subsector. The commenter opposed the addition of
any refrigerants with a GWP of greater than 150, as required under the proposed

Technology Transitions Rule, including R-454A in self-contained equipment.
Response: In this final rule, EPA is listing HFC-32, R-454A, and R-454Bx as
acceptable, subject to use conditions, for remote condensing and larger self-contained
commercial ice machines and is listing HFO-1234yf, R-454C, R-455A, R-457A, and R516A as acceptable, subject to use conditions, for all commercial ice machines. The
Agency is aware that commercial ice machine manufacturers have found it difficult to
design for the use of alternative refrigerants with a GWP less than 150 (like carbon
dioxide and R-717) that have adequate performance properties (e.g., sufficiently high
pressure and volumetric capacity and a lower boiling point) for use with larger equipment
(i.e., with a larger ice harvest rate) or with a remote condenser; thus, EPA is listing three
refrigerants as acceptable in this rule that have a GWP of greater than 150 that equipment
manufacturers have been testing for use in commercial ice machines (i.e., HFC-32, R454A, and R-454B). These three refrigerants have GWPs of 237 for R-454A, 465 for R454B, and 675 for HFC-32, which are still lower than or comparable to refrigerants such
as R-450A or R-513A, with GWPs of approximately 600 and 630. Further, their GWPs
are significantly lower than commonly used HFC blends such as R-410A with a GWP of
2,090 and R-404A with a GWP of 3,920.
In response to comments related to the Technology Transitions Rule, as noted
previously in this preamble, EPA agrees that there may be circumstances where there is
little practical value in finalizing an acceptable listing for an alternative where the
Technology Transitions Rule would restrict its use. However, that is not the situation here
for this listing for R-454A with a GWP of 237, R-454B with a GWP of 465, and HFC-32
with a GWP of 675, for use in remote condensing and larger self-contained commercial
ice machines. The Agency notes that the final Technology Transitions Rule categorizes
self-contained commercial ice machines differently than in the proposed Technology
Transitions Rule. EPA restricted refrigerants to those with a GWP of less than 150 for

self-contained commercial ice machines with a harvest rate less than or equal to 1,000 or
1,200 pounds of ice per 24 hours (depending on whether the equipment was batch-type or
continuous-type). Self-contained commercial ice machines with greater harvest rates are
restricted from using certain higher-GWP HFC blends under that rule, but the refrigerants
being listed in this final SNAP rule are not otherwise prohibited under the final
Technology Transitions Rule. EPA did not propose, and is not finalizing in this action, a
use condition restricting the use of those refrigerants that have a GWP of 150 or greater
(i.e., HFC-32, R-454A, and R-454B). While EPA is not finalizing such a restriction in
this action, in the future, EPA may consider further whether such a restriction would be
appropriate under SNAP. EPA additionally notes, however, those refrigerants are still
prohibited under the final Technology Transition rule for self-contained commercial ice
machines with harvest rates less than or equal to 1,000 or 1,200 pounds per day.
D. Commercial Ice Machines—Revision of the use conditions in the previous
listing of R-290 as acceptable, subject to use conditions, for use in new self-contained
commercial ice machines
EPA is revising use conditions in the existing listing of R-290 as acceptable,
subject to use conditions, for use in new elf-contained commercial ice machines
established in SNAP Rule 21 (81 FR 86779, December 1, 2016). In this final rule, we are
updating those use conditions to be consistent with the most recent U.S. national industry
safety standard for commercial refrigeration equipment, including self-contained
commercial ice machines, UL 60335-2-89. Among other things, these revisions will
allow safe use of larger charge sizes of R-290 than under the previous use condition
requiring an earlier standard, UL 563, which will allow for broader use of R-290 as an
alternative in this end-use. Similar use conditions apply to other refrigerants with lower
flammability in this SNAP action in section II.C of this preamble. The final use
conditions are allowed for such equipment manufactured on or after the effective date of

this final rule and do not apply to nor affect equipment manufactured before that effective
date.
This revision to the use conditions incorporates by reference a newer industry
standard, changing the reference from Supplement SA to the 8th edition, dated July 31,
2009, of UL 563, “Ice Makers” to UL 60335-2-89. EPA is providing a transition period
during which self-contained commercial ice machines manufactured with R-290 may
follow either UL 563 or UL 60335-2-89. After the transition period ends, new selfcontained commercial ice machines manufactured with R-290 must follow UL 60335-289 for purposes of the SNAP program, except as noted below for models that remain
essentially unchanged from their earlier UL certification to UL 563.
Several use conditions finalized for this end-use are similar to those finalized for
other end-uses. Because of this similarity, EPA discusses the use conditions that apply to
all five end-uses in section II.H of this preamble. In summary, the common use
conditions are: restricting the use of the refrigerant to new equipment that is specifically
designed and clearly marked for that refrigerant; use consistent with ASHRAE 15-2022
and with UL 60335-2-89 including testing, charge sizes, ventilation, usage space
requirements, and certain hazard warnings and markings; and requirements for warning
labels and markings on equipment to inform consumers, technicians, and first responders
of potential flammability hazards. The regulatory text of the use conditions appears in
tables at the end of this document.
In this final action, EPA is revising the existing listing for R-290 in new selfcontained commercial ice machines in appendix V to 40 CFR part 82, subpart G. The
revised regulatory text contains listing decisions for new self-contained commercial ice
machines in appendix V. EPA is also republishing certain other previous listings for
purposes of formatting for the Federal Register; EPA is not finalizing substantive
changes to those earlier decisions (e.g., listings for R-290 in new water coolers and in

new very low temperature refrigeration equipment).
1. Background on commercial ice machines
See section II.C.1 of this preamble for background on this end-use.
2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes R-290 as being in the A3 Safety Group. See
section II.A.2 of this preamble for further discussion on ASHRAE classifications.
3. What is R-290 and where is there information on its use in this end-use?
See section II.B.3 of this preamble for further discussion on the identity,
environmental, flammability, toxicity, and exposure information for R-290.
Redacted submissions and supporting documentation for R-290 are provided in
the docket for this final rule (EPA-HQ-OAR-2023-0043) at https://www.regulations.gov.
EPA performed a risk screening assessment to examine the health and environmental
risks of this refrigerant in self-contained commercial ice machines. The risk screen is
available in the docket for this final rule.51
4. What existing use conditions apply to this refrigerant in this end-use?
EPA previously listed R-290 acceptable, subject to use conditions, in new selfcontained commercial ice machines in SNAP Rule 21 (81 FR 86779, December 1, 2016).
Those requirements are codified in appendix V to 40 CFR part 82, subpart G. EPA
provided information on the environmental and health risks of R-290 and the various
substitutes available at that time for use in this end-use. Additionally, EPA's previous risk
screen for this refrigerant, based on the use conditions in that rule, is available in the
docket for that previous rulemaking (EPA-HQ-OAR-2015-0663).
R-290 has an ASHRAE classification of A3, indicating that it has low toxicity and
higher flammability. In the presence of an ignition source (e.g., static electricity, a spark

ICF, 2023q. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment); Substitute: (R290).
resulting from a closing door, or a cigarette), an explosion or a fire could occur if the
concentration of R-290 were to exceed the LFL of 21,000 ppm (2.1 percent) by volume.
The use conditions established in the 2016 listing for R-290 in new self-contained
commercial ice machines addressed safe use of this flammable refrigerant and included
the following: incorporation by reference of Supplement SA to the 8th edition (July 31,
2009, including revisions through November 29, 2013) of UL 563, “Ice Makers;”
refrigerant charge size limits based on cooling capacity and type of equipment; and
requirements for markings and warning labels on equipment using the refrigerant to
inform consumers, technicians, and first responders of potential flammability hazards.
Our assessment and listing decisions in SNAP Rule 21 (81 FR 86779, December 1, 2016)
found that with the use conditions, the overall risk of this refrigerant, including the risk
due to flammability, was not greater in this end-use than other substitutes that are
currently or potentially available for that same end-use.
5. What updates to existing use conditions for commercial ice machines is
EPA finalizing?
EPA is finalizing the proposed use conditions that apply to R-290 in new selfcontained commercial ice machines manufactured on or after the effective date of this
final rule. Several of the updated use conditions finalized for use of R-290 in selfcontained commercial ice machines are common to those finalized for the stand-alone
units end-use in section II.B of this preamble. Other use conditions are common to all
refrigerants and all five end-uses in this final rule. Because of this similarity, EPA
discusses the use conditions that apply to all five end-uses in section II.H of this
preamble. For R-290 in self-contained commercial ice machines, these are the only
revised use conditions EPA is finalizing. In summary, the common use conditions for all
five end-uses are: restricting the use of the refrigerant to new equipment that is
specifically designed and clearly marked for that refrigerant; use consistent with

ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions), including testing,
charge sizes, ventilation, usage space requirements, and certain hazard warnings and
markings; and requirements for warning labels and markings on equipment to inform
consumers, technicians, and first responders of potential flammability hazards.
EPA is finalizing the use conditions in this action, which apply to new selfcontained commercial ice machines manufactured on or after the effective date of this
final rule. This final rule does not apply to nor affect equipment manufactured before that
effective date. The final regulatory text presents these different requirements as numbered
listings in separate table rows, where the end-use and the effective time period during
which the equipment is manufactured are in the left-most column, with the heading “Enduse”; the specific requirements are listed as use conditions in the fourth column, with the
heading “Use Conditions.” Under SNAP, EPA views equipment to be manufactured at
the date upon which the appliance’s refrigerant circuit is complete, the appliance can
function, the appliance holds a full refrigerant charge, and the appliance is ready for use
for its intended purposes. For new self-contained commercial ice machines, this occurs at
the factory. New self-contained commercial ice machines manufactured using R-290
between January 3, 2017, and the effective date of this final rule are required to meet the
use conditions in SNAP Rule 21 (which took effect January 3, 2017) and as listed in
appendix V to 40 CFR part 82, subpart G (in listing 1), including the use condition
incorporating by reference Supplement SA to the 8th edition of UL 563. Such products
are permitted to be warehoused and sold through normal channels, even if they are sold
after the effective date of this final rule. Self-contained ice machines using R-290
manufactured on or after the effective date of this final rule are required to meet the use
conditions finalized and listed in the revisions to appendix V. Those use conditions allow
manufacturers of new self-contained commercial ice machines using R-290 to follow
either UL 563 or UL 60335-2-89, dependent upon which standard the equipment was

manufactured, from the effective date of this final rule and will last through September
29, 2024, which is the date when UL is sunsetting UL 563. On and after September 30,
2024, new self-contained commercial ice machines using R-290 for any new equipment
designs or models must meet UL 60335-2-89; for an unchanged model or design that was
already listed by UL—that is, already certified to meet the requirements of UL 563—it
could continue to meet those requirements.
EPA is finalizing use conditions allowing all new self-contained commercial ice
machines using R-290 to be manufactured consistent with Supplement SA of UL 563, up
to and including September 29, 2024. Therefore, during the time between the effective
date of this final rule and September 29, 2024, manufacturers may follow either UL 563,
8th edition or UL 60335-2-89, 2nd edition, depending on which standard the equipment
was designed to. This transition date was in this rule’s proposal in order to align with the
industry standard sunsetting date for UL 563. It is EPA’s understanding that since
proposal, UL has discussed updating its effective date when UL 60335-2-89 replaces UL
563 to reflect a later continuing certification date. EPA is allowing manufacturers to
adhere to either standard for this limited time because the Agency recognizes that
manufacturers may need time to make necessary changes including to their product
labels. The period during which manufacturers may follow either standard should provide
sufficient time for manufacturers to transition from UL 563 to UL 60335-2-89 while
designing and testing new models and designs. Beginning September 30, 2024, for the
purposes of the SNAP program, newly manufactured self-contained commercial ice
machines of new models and designs using R-290 must meet the requirements of UL
60335-2-89. Newly manufactured self-contained commercial ice machines of existing
models and designs that are certified (e.g., UL-listed) using R-290 that remain unchanged
other than cosmetic changes (e.g., color changes) and that meet Supplement SA of UL
563 prior to September 30, 2024, may continue to meet those requirements after that date.

In addition, EPA is requiring manufacturers to follow the set of use conditions that
correspond with a specific UL standard (e.g., EPA included text in the revisions to
appendix V stating that when an entity is using UL 563, it is to follow all use conditions
in listing 1 and when using UL 60335-2-89, it is to follow all use conditions in listing 3 in
the final revisions to appendix V). See section II.H.1of this preamble for further
discussion on the requirements of UL 60335-2-89, 2nd edition, which EPA is
incorporating by reference.
EPA also notes that we are continuing to apply without revision two existing use
conditions, nor did we take comment on those two existing use conditions. The use
conditions that restrict the use of R-290 to new equipment specifically designed for this
refrigerant, and that require red-colored markings at service ports, pipes, hoses, and other
devices through which the refrigerant is serviced, are existing use conditions for R-290 in
new self-contained commercial ice machines.
6. How do the new use conditions for commercial ice machines differ from the
existing ones and why is EPA changing the use conditions?
The revised use conditions EPA is finalizing for self-contained commercial ice
machines are similar to the ones that exist today in appendix V to 40 CFR part 82,
subpart G, for R-290 in this end-use. The existing requirements that R-290 must be used
in new equipment only and that new self-contained commercial ice machines must
include red markings at service ports, pipes, hoses, and other devices through which the
refrigerant is serviced, are repeated in this final listing. The revised use conditions
concern incorporating by reference the most recent U.S. industry standard for commercial
ice machines and labeling requirements consistent with that new standard. Self-contained
commercial ice machines using R-290 manufactured before the effective date of this final
rule are not affected by the revised use conditions.
Warning labels are required under EPA’s existing regulations, and EPA is

continuing to require them, although with some specific language changes. The finalized
warning labels are identical to those previously required as use conditions for the use of
R-290 in self-contained commercial ice machines. Using a common set of labels, like
those in UL 60335-2-89, aids in compliance and could reduce burden for the industry,
especially for a manufacturer that uses more than one refrigerant. EPA is finalizing that
the labels must be provided in letters no less than 6.4 millimeter (¼ inch) high and must
be permanent, which is identical to the existing requirement for R-290 in self-contained
commercial ice machines.
EPA is incorporating by reference a newer industry standard in the use conditions,
including use of UL 60335-2-89, 2nd edition, instead of continuing to require the standard
Supplement SA of the 8th edition of UL 563 for equipment manufactured on or after the
effective date of this final rule. UL 60335-2-89 was developed in an open and consensusbased approach, with the assistance of experts in the refrigeration and AC industry as
well as experts involved in assessing the safety of products. The revision cycle for the 2nd
edition, including final recirculation, concluded with its publication on October 27, 2021.
The 2021 standard UL 60335-2-89 replaces the previously published version of several
standards, including UL 563, which had already been revised into an 8th edition by that
time. EPA is aware of the continuing progress of UL standards to address flammable
refrigerants. Today, we are finalizing such a change knowing that UL is replacing the
standard to which such equipment is UL-listed from UL 563 to the newer UL 60335-2-89
as of September 30, 2024.
To allow time for manufacturers of self-contained commercial ice machines to
transition between the existing use condition using the 8th edition of UL 563 and the new
use condition using UL 60335-2-89, EPA is allowing R-290 to be used in self-contained
commercial ice machines manufactured either following UL 563 or UL 60335-2-89
during a transition period. That transition period begins on the effective date of this final

rule and lasts through September 29, 2024. It is EPA’s understanding that UL intends to
sunset UL 563 on September 29, 2024, and EPA is coordinating with that sunset date.
Further, based on public comments, EPA understands that UL allows newly
manufactured equipment that remains unchanged from its previous UL-listed (certified)
design or model to continue to follow an earlier standard such as UL 563 because the
manufacturer has made no changes. EPA is adopting a similar approach, as well, in this
final rule. Beginning September 30, 2024, the use condition allows R-290 to be used in
new self-contained commercial ice machines that follow UL 60335-2-89 or in newly
manufactured stand-alone units that are unchanged from the model or design previously
UL-listed as meeting UL 563, 8th edition. In addition, manufacturers must follow the set
of use conditions that correspond with a specific UL standard (i.e., when using UL 563,
follow all use conditions in listing 1 and when using UL 60335-2-89, follow all use
conditions in listing 3 in the final revisions to appendix V of part 82, subpart G).
Another revision to the use conditions is the limit on charge sizes. The existing
use conditions from SNAP Rule 21 require charge sizes to be calculated consistent with
UL 563, with a maximum charge size of 150 g allowed. The final revised use conditions
for equipment manufactured on or after the effective date of this final rule allow charge
sizes calculated based on UL 60335-2-89, which allows charge sizes of R-290 up to
approximately 500 g for open equipment, 300 g for equipment with doors or drawers, or
115 g for equipment near a pathway for egress. These changes allow the use of R-290 in
larger equipment than previously and provide more options for industry, while
maintaining environmental health and human safety.
Because of the differences between UL 563 and UL 60335-2-89, EPA performed
a new risk screen for R-290 as a refrigerant in self-contained commercial ice machines.52
In this risk screen, EPA adjusted charge sizes to be consistent with the larger charge sizes

ICF, 2024q. Op. cit.

allowed for R-290 under UL 60335-2-89. The risk screen also considered the impact of
mitigation methods such as valves that would restrict the amount of refrigerant that could
be released. The updated risk screen found that concentrations of R-290 still would not
exceed the LFL when used according to the new use condition with releasable charges
and larger charge limits and consistent with UL 60335-2-89, and thus the new use
conditions also address flammability risks of using R-290.53 In addition, the risk screen
modeled the reasonable worst-case scenario of short-term exposure (15-minute TWA)
due to a catastrophic release of the charge. Under this highly conservative scenario, the
worst-case exposure was still significantly lower than the ATEL of 50,000 ppm.54 For
further information, see the risk screen55 for R-290 in self-contained commercial ice
machines in the docket for this rulemaking.
7. What additional information is EPA including in this listing?
EPA is providing additional information related to this final listing. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the substitute under the SNAP program. While the
items listed are not legally binding under the SNAP program, EPA encourages users of
substitutes to apply all statements in the “Further Information” column in their use of
these refrigerants. See section II.H.2 of this preamble for further discussion on what
additional information EPA is including in these listings. EPA notes that the additional
information is similar to, but not identical with, the additional information in the listing
for R-290 in self-contained commercial ice machines in SNAP Rule 21. EPA is finalizing
additional information to that included in the listings for R-290 in self-contained
commercial ice machines in SNAP Rule 21.
8. How is EPA responding to comments on listing R-290 and updating the
Ibid.
Ibid.
55 Ibid.
53
use conditions for R-290 in self-contained commercial ice machines?
Comment: One commenter expressed that EPA should not allow for the use of R290 in commercial ice machines with remote compressors that are not self-contained due
to flammability concerns. Specifically, the commenter stated that the use of R-290 is
restricted in UL 60335-2-89 to self-contained equipment to lessen the risks associated
with higher flammability refrigerants.
Response: EPA agrees with the commenter that R-290 should not be allowed in
commercial ice machines with remote compressors that are not self-contained due to
flammability concerns. The 2nd edition of UL 60335-2-89 limits the use of R-290 to selfcontained commercial ice machines, and that standard does not allow for use the use of
R-290 in commercial ice machines with remote compressors. EPA is finalizing use
conditions for R-290 in this final rule that are consistent with using R-290 only in selfcontained commercial ice machines and is not listing R-290 as acceptable in commercial
ice machines with remote compressors.
Comment: Two commenters suggested clarifications surrounding manufacturers’
use of R-290 in self-contained products (150 grams or less). They noted that UL will
allow manufacturers to continue under UL 563 requirements until a significant product
change is made or the manufacturer withdraws their file. The commenters stated that only
at that time will R-290 equipment become subject to 60335-2-89. They asked for EPA to
clarify this in the final rule.
Response: EPA addressed a similar comment with respect to refrigerated food
processing and dispensing equipment end-uses in section II.B.10 of this preamble. Those
reasons are also applicable to this end-use and for the same reasons, EPA is finalizing an
end-use description and use conditions for R-290 in this final rule that are consistent with
using R-290 only in self-contained commercial ice machines and not in commercial ice
machines with remote compressors.

E. Industrial Process Refrigeration—Listing of HFC-32, HFO-1234yf, HFO1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A as acceptable,
subject to use conditions, for use in new industrial process refrigeration
This final rule lists HFC-32, HFO-1234yf, HFO-1234ze(E), and the refrigerant
blends R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A as acceptable, subject
to use conditions, for use in new IPR equipment. HFO-1234yf, HFO-1234ze(E), and the
refrigerant blends R-454C, R-455A, R-457A, and R-516A are being listed for all IPR
equipment including both chillers and non-chiller—e.g., direct expansion (DX)—IPR
equipment. The listings for refrigerants HFC-32, R-454A, and R-454B are being finalized
in this rule only for chillers for IPR and for DX IPR equipment where the temperature of
the refrigerant entering the evaporator is less than or equal to -30 °C and for R-454A, also
may be used in DX IPR equipment with a refrigerant charge capacity less than 200
pounds or in the high-temperature side of a cascade system with the refrigerant
temperature entering the evaporator higher than -30 °C. EPA is not finalizing listings for
those three refrigerants for other IPR uses at this time. EPA is modifying the proposed
use conditions for R-454A, R-454B, and HFC-32 to also allow these substitutes in direct
expansion IPR equipment with refrigerant entering the evaporator at temperatures less
than or equal to -30 °C, based on public comment regarding the limited availability of
substitutes for this particular temperature range and based upon our comparative risk
analysis concluding that these substitutes for these specific uses and use conditions are
not expected to pose greater risk to overall health or the environment. EPA is not
reaching a final decision in this rule on these refrigerants for other IPR uses for HFC-32
and R-454B (i.e., for DX IPR equipment with the refrigerant temperature entering the
evaporator higher than -30 °C).
Most of the use conditions finalized for the A2L refrigerants when used in IPR are
the same as those finalized for other end-uses. Because of this similarity, EPA discusses

the use conditions that apply to all five end-uses in section II.H of this preamble. In
summary, the common use conditions are: restricting the use of each refrigerant to new
equipment that is specifically designed and clearly marked for that refrigerant; use
consistent with ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions),
including testing, charge sizes, ventilation, usage space requirements, and certain hazard
warnings and markings; and requirements for warning labels and markings on equipment
to inform consumers, technicians, and first responders of potential flammability hazards.
In addition to the common use conditions discussed in section II.H of this
preamble, the following use condition also applies to HFC-32 and R-454B in IPR: these
refrigerants may only be used in IPR: 1) For chillers or 2) for equipment that is not a
chiller withe the refrigerant temperature entering the evaporator is less than or equal to 30 °C.
The following use condition also applies for R-454A in IPR: this substitute may
only be used in IPR 1) for chillers, 2) equipment with the refrigerant temperature entering
the evaporator less than or equal to -30 °C, 3) equipment with a refrigerant charge
capacity less than 200 pounds and with the refrigerant temperature entering the
evaporator higher than −30 °C (−22 °F), and 4) in the high-temperature side of a cascade
system with the refrigerant temperature entering the evaporator higher than -30 °C.
The regulatory text of the final decisions appears in tables at the end of this
document and is being codified in appendix Y to 40 CFR part 82, subpart G. The final
regulatory text contains listing decisions for the end-use discussed in this section. EPA
notes that there may be other legal obligations pertaining to the manufacture, use,
handling, and disposal of these refrigerants that are not included in the information listed
in the tables (e.g., the CAA section 608(c)(2) venting prohibition or DOT requirements
for transport of flammable gases). Flammable refrigerants being recovered or otherwise
disposed of from IPR equipment are likely to be hazardous waste under RCRA (see 40

CFR parts 260 through 270).
1. Background on industrial process refrigeration
IPR systems cool process streams in industrial applications, for example,
machining of metal products, fermentation of beer, or operation of hydraulic circuits. The
choice of refrigerant for specific applications depends on ambient and required operating
temperatures and pressures. It is EPA’s understanding that this type of equipment may
fall under the scope of ASHRAE 15-2022. This type of equipment also typically falls
under the scope of UL 60335-2-89, “Requirements for Commercial Refrigerating
Appliances and Ice-Makers with an Incorporated or Remote Refrigerant Unit or MotorCompressor” if it is not used in an industrial occupancy56 and that it always falls under
ASHRAE 15. In contrast, industrial process air conditioning primarily cools people,
although it may also cool processes, and follows a different UL standard (UL 60335-240). When chillers are used primarily to cool process streams, rather than for comfort
cooling, SNAP describes this application as “chillers in IPR.”
2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes the refrigerants listed for IPR in this section as
being in the A2L Safety Group. See section II.A.2 of this preamble for further discussion
on ASHRAE classifications.
3. What are HFC-32, HFO-1234yf, HFO-1234ze(E), R-454A, R-454B, R454C, R-455A, R-457A, and R-516A and how do they compare to other
refrigerants in the same end-use?
See sections II.A.3 and II.C.3 of this preamble for further discussion on the
environmental, flammability, toxicity, and exposure information for these refrigerants.
The redacted submission and supporting documentation for HFC-32, HFO-

ASHRAE 15-2022 defines industrial occupancy as, “a premise or that portion of a premise that is not
open to the public, where access by authorized persons is controlled, and that is used to manufacture,
process, or store goods such as chemicals, food, ice, meat, or petroleum.”
1234yf, HFO-1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A is
provided in the docket for this rule (EPA-HQ-OAR-2023-0043) at
https://www.regulations.gov. EPA performed risk screening assessments to examine the
health and environmental risks of these refrigerants. These risk screens are available in
the docket for this rule.57,58,59,60,61,62,63,64,65
Comparison to other substitutes in this end-use: HFC-32, HFO-1234yf, HFO1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A all have an ODP of
zero, comparable to or lower than some of the acceptable substitutes in new IPR
equipment, such as HFC-134a, R-410A, and R-513A with ODPs of zero and
hydrochlorofluoroolefin (HCFO)-1233zd(E) with an ODP less than 0.0004.66
HFO-1234yf and HFO-1234ze(E) both have a GWP of one, comparable to that of
R-290 and ammonia with GWPs of three and zero. R-454A, R-454B, R-454C, R-455A,
R-457A, and R-516A have GWPs ranging from 140 to 470, higher than some of the
acceptable substitutes for new IPR equipment, including R-290 and ammonia, and lower
than those of other substitutes such as R-450A and R-513A with GWPs of about 600 and
630. HFC-32, which EPA is restricting to use in chillers for IPR or in IPR equipment
with the refrigerant temperature entering the evaporator is less than or equal to -30 °C,

ICF, 2023r. Risk Screen on Substitutes in Industrial Process Refrigeration (New Equipment); Substitute:
HFC-32 (Difluoromethane).
58 ICF, 2023s. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: HFO-1234yf.
59 ICF, 2023t. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: HFO-1234ze(E) (Solstice® ze, Solstice® 1234ze).
60 ICF, 2023u. Risk Screen on Substitutes in Industrial Process Refrigeration and Cold Storage Warehouses
(New Equipment); Substitute: R-454A (Opteon® XL40).
61 ICF, 2023v. Risk Screen on Substitutes in Industrial Process Refrigeration (New Equipment); Substitute:
R-454B (Opteon® XL41).
62 ICF, 2023w. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: R-454C (Opteonâ„¢ XL20).
63 ICF, 2023x. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: R-455A (Solstice® L40X).
64 ICF, 2023y. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: R-457A.
65 ICF, 2023z. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage Warehouses,
and Ice Skating Rinks (New Equipment); Substitute: R-516A.
66 WMO, 2022.
has a GWP of 675, which is higher than some of the acceptable substitutes including R290, R-450A, and R-513A; however, the GWP of HFC-32 is lower than those of R-410A
and R-404A, with GWPs of approximately 2,090 to 3,920, which are refrigerants that
have typically been employed in chillers for IPR, but as of January 1, 2026 or January 1,
2028, depending on the temperature range, will be subject to restrictions in new IPR
systems under the Technology Transitions Rule. In light of that upcoming restriction,
EPA is listing HFC-32 and R-454B to provide additional lower-GWP, low-temperature
refrigerants in these end-uses. This upcoming restriction, and the corresponding value of
providing additional lower-GWP, low temperature refrigerants in these end-uses, are
additional considerations that informed EPA’s decision on this listing.
Information regarding the toxicity of other available alternatives is provided in the
previous listing decisions for new IPR equipment (https://www.epa.gov/snap/substitutesindustrial-process-refrigeration). Toxicity risks of use, determined by the likelihood of
exceeding the exposure limits of HFC-32, HFO-1234yf, HFO-1234ze(E), R-454A, R454B, R-454C, R-455A, R-457A, and R-516A in this end-use, are evaluated in the risk
screens referenced previously. The toxicity risks of using HFO-1234yf and the refrigerant
blends in IPR, and of using all nine refrigerants in chillers for IPR, are comparable to or
lower than toxicity risks of other available substitutes in the same end-use. Toxicity risks
of these refrigerants can be mitigated by use consistent with ASHRAE 15-2022 and other
industry standards, recommendations in the manufacturers’ SDS, and other safety
precautions common in the refrigeration and AC industry.
The flammability risks with HFC-32, HFO-1234yf, HFO-1234ze(E), R-454A, R454B, R-454C, R-455A, R-457A, and R-516A in the IPR end-use, determined by the
likelihood of exceeding their respective LFLs, are evaluated in the risk screens referenced
in this section. While these refrigerants may pose greater flammability risk than available
substitutes in the new IPR end-use that are non-flammable, this risk can be mitigated by

use consistent with ASHRAE 15-2022 and, if applicable, UL 60335-2-89, as required by
our use conditions, as well as recommendations in the manufacturers’ SDS and other
safety precautions common in the refrigeration and AC industry. We also note that other
acceptable refrigerants in the IPR end-use have higher flammability and are classified in
the A3 Safety Group, such as R-290, butane (R-600), and propylene (R-1270). EPA is
finalizing use conditions to reduce the potential risk associated with the flammability of
the alternatives so that they will not pose greater overall risk to human health and the
environment than other acceptable substitutes for new equipment in the IPR end-use.
In addition, the listed substitutes have lower GWPs than most other available
alternatives for the same uses. The listed refrigerants may provide additional lower-GWP
options for situations where other refrigerants with lower GWPs are not viable, such as
situations where sparks or flame might occur such that HCs are not suitable for use, or for
systems with remote compressors or equipment requiring larger charge sizes, where
refrigerant leaks are more likely to create greater flammability risk. Given the wide range
of applications for IPR, not all refrigerants listed as acceptable under SNAP will be
suitable for the range of equipment in the IPR end-use. To provide additional options to
ensure the availability of refrigerants with lower GWPs for the full range of IPR
equipment and, therefore, lower overall risk to human health and the environment, EPA
is listing HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A as
acceptable, subject to use conditions, for use in IPR.
EPA is also listing the refrigerants HFC-32 and R-454B with a use condition
restricting their use to chillers in IPR or in IPR equipment with the refrigerant
temperature entering the evaporator is less than or equal to -30 °C. These refrigerants
have higher GWPs than the other refrigerants EPA is listing as acceptable, subject to use
conditions, but lower GWPs than many refrigerants typically used today in chillers for
IPR, such as R-410A and R-404A, with GWPs of 2,090 and 3,290 respectively (but will

be restricted as soon as January 1, 2026). These refrigerants also have lower flammability
than HC refrigerants currently listed as acceptable in IPR. In light of upcoming
restrictions under the Technology Transitions Rule, EPA is listing additional substitutes
for use in these end-uses. The Agency expects that these refrigerants may provide
additional, lower-GWP options for chillers for IPR, where greater volumetric capacity
and higher operating pressures may be required to operate properly than for other types of
IPR equipment (e.g., direct expansion systems), to address applications where other
substitutes with lower GWPs may not be technically feasible, safe to human health, or
environmentally suitable. In addition, these refrigerants may provide additional, lowerGWP options for IPR equipment where the temperature of the refrigerant needs to attain
temperatures less than or equal to -30 °C; fewer refrigerants have boiling points low
enough to achieve these lower temperatures, and thus, EPA is also finalizing listings for
HFC-32 and for R-454B, with boiling points of -51.9 °C and -51 °C, respectively, to
provide additional options.
EPA is also listing the refrigerant R-454A with a use condition that this substitute
may only be used either in chillers for IPR, in equipment with a refrigerant charge
capacity less than 200 pounds, in the high-temperature side of a cascade system, or in
IPR equipment with the refrigerant entering the evaporator is less than or equal to -30 °C.
This refrigerant may provide additional, lower-GWP options for chillers for IPR, where
greater volumetric capacity and higher operating pressures may be required to operate
properly than for other types of IPR equipment. R-454A may also address the additional
challenges for finding lower-GWP refrigerants with higher capacity for non-chiller IPR
equipment with moderate charge sizes and for cascade systems; hence, EPA is listing R454A as acceptable, subject to use conditions, for use in new non-chiller IPR equipment
with a charge size capacity less than 200 pounds or for use in the high-temperature side
of a cascade system. In addition, these refrigerants may provide additional, lower-GWP

options for IPR equipment where the temperature of the refrigerant needs to attain
temperatures less than or equal to -30 °C; fewer refrigerants have boiling points low
enough to achieve these lower temperatures, and thus, EPA is also finalizing a listing for
R-454A in IPR equipment with the refrigerant temperature entering the evaporator is less
than or equal to -30 °C (with a boiling point of -48 °C) to provide additional options.
4. Why is EPA finalizing these specific use conditions?
The final use conditions identified in the listings for all nine refrigerants are
explained in the proceeding paragraphs and in section II.H.1 of this preamble.
EPA is finalizing the use conditions for HFC-32 and R-454B restricting their use
to chillers for IPR or in IPR equipment with the refrigerant temperature entering the
evaporator is less than or equal to -30 °C because these refrigerants have higher GWPs
than many of the available substitutes in IPR (e.g., HCs, HFOs); however, because
chillers may require greater volumetric capacity than other types of IPR equipment (e.g.,
DX systems), and because some IPR applications require temperatures below -30 °C,
EPA is listing these two additional refrigerants to provide additional lower-GWP options
that pose lower overall risk to human health and the environment than other available
substances and to address a broader range of equipment and applications. EPA also is
finalizing a use condition for R-454A that allows its use in chillers for IPR or in IPR
equipment with the refrigerant temperature entering the evaporator is less than or equal to
-30 °C, as well as other certain other applications, as described in this section. In
addition, EPA is listing HFC-32, R-454A, and R-454B as acceptable, subject to use
conditions, for chillers because of technical limitations, such as volumetric capacity,
operating pressure, and temperature range, which restrict the technical viability of some
other safe and environmentally suitable alternatives for some applications. The Agency
previously listed these three refrigerants as acceptable, subject to use conditions, in
centrifugal and positive displacement chillers for comfort cooling in SNAP Rule 25

because of the same technical concerns and with the same use conditions as EPA is
finalizing here. In addition, these use conditions are consistent with restrictions on
refrigerants that contain HFCs under the final Technology Transitions Rule, allowing for
greater consistency and reducing potential confusion for the regulated community.
EPA is finalizing the use condition for R-454A, restricting its use to chillers for
IPR, equipment with a refrigerant charge capacity less than 200 pounds, the hightemperature side of a cascade system, or IPR equipment with the refrigerant temperature
entering the evaporator is less than or equal to -30 °C. EPA is listing R-454A for use in
chillers for IPR and in IPR equipment with the refrigerant temperature entering the
evaporator is less than or equal to -30 °C for the same reasons as for HFC-32 and R454B. The Agency is also finalizing this use condition to allow use of R-454A less
broadly than for the refrigerants HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R457A, and R-516A because its GWP is higher than those other listed refrigerants for nonchiller IPR equipment (R-454A has a GWP of about 237, compared to one to 150).
EPA’s understanding is that, in addition to the technical constraints for refrigerant
in chillers for IPR, there are two more situations where use of refrigerants is likely to be
more constrained, and thus, additional refrigerant options that reduce overall risk to
human health and the environment may be helpful. The first of those situations is where
ASHRAE 15-2022 identifies a refrigerating system as having a “high probability” that
leaked refrigerant from a failed connection, seal, or component could enter an occupied
area. UL 60335-2-89 effectively sets charge limits for A2L refrigerants to 260 times the
LFL for applications inside an occupied space where people might be located. This
amount is approximately 200 pounds, depending on the LFL of the particular refrigerant.
In contrast, larger charge sizes in equipment meeting the requirements of ASHRAE 15
could be used in “low-probability” locations where the general public is unlikely to come
in contact with the refrigerant, such as systems used in industrial occupancies, outdoors,

or in a machinery room with access restricted to facility employees. Where the general
public is unlikely to come into contact with any leaked refrigerant, there would be fewer
space constraints and greater flexibility in equipment design, so refrigeration system
designers can accommodate a narrower set of refrigerants. Conversely, where people are
more likely to come into contact with any leaked refrigerant in an interior space, which
are not industrial occupancies, refrigerant charge capacities of a system would be less
than 200 pounds. In addition, in such public spaces there would be more space
constraints, less flexibility in equipment design, and potentially stricter code
requirements. EPA recognizes that these may be situations where R-454A can be used
where those other refrigerants cannot, especially where space is constrained. Therefore,
R-454A fills a gap in the stated end-uses where lower-GWP refrigerant alternatives are
not as available, and R-454A’s GWP of approximately 237 and similar toxicity and
flammability profiles would pose lower overall risk to human health and the environment
than other available refrigerants. Therefore, EPA is listing R-454A as acceptable, subject
to use conditions, for non-chiller IPR equipment with a refrigerant charge capacity less
than 200 pounds (and with the refrigerant temperature entering the evaporator higher than
-30 °C).
The second situation where use of refrigerants is likely to be more constrained,
and therefore where EPA is listing R-454A, is for use in the high-temperature side of
cascade systems used for non-chiller IPR equipment (and with the refrigerant temperature
entering the evaporator higher than -30 °C). As discussed in section II.A.1 of this
preamble, “Background on retail food refrigeration,” each side of a cascade system uses a
different refrigerant that is most suitable for the given temperature range. Higher
temperature systems, or the “high-temperature side,” have typically used HFCs as a
refrigerant; however, it is technologically achievable and has become more common to
use ammonia in the high-temperature side. For lower temperature systems, or the “low

temperature side” of the cascade system, refrigerants with low boiling points such as R744 can be used. Considerations for the choice of refrigerant on the high or low
temperature side of cascade systems are influenced by many factors including, but not
limited to, a refrigerant’s toxicity and flammability, its temperature glide, and its
suitability to lower temperature applications. There are a number of substitutes available
for the low temperature side of a cascade system with GWPs lower than that of R-454A.
However, using flammable or toxic refrigerants, such as ammonia, on the hightemperature side of a cascade system may be limited in certain circumstances (e.g., based
on building codes and/or industry safety standards). Therefore, EPA is listing R-454A as
acceptable, subject to use conditions, when it is used in the high-temperature side of
cascade systems (and with the refrigerant temperature entering the evaporator higher than
-30 °C). This action expands the lower-GWP refrigerant options that reduce overall risks
to human health and the environment and that can comply with local building codes and
industry safety standards while meeting the more challenging application of the hightemperature side of a cascade system.
5. What additional information is EPA including in these listings?
EPA is providing additional information related to these listings. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the substitute under the SNAP program. However,
EPA encourages users of substitutes to apply all statements in the “Further Information”
column in their use of these refrigerants. See section II.H.2 of this preamble for further
discussion on what additional information EPA is including in these listings.
6. How is EPA responding to comments on industrial process
refrigeration?
Comment: Three commenters addressed the use of R-454B and HFC-32 in the
IPR end-use. These commenters claimed that R-454B and HFC-32 are needed for IPR

beyond chillers and requested that EPA approve them for all IPR applications such as
industrial, medical, and laboratory applications. They provided additional details that
these refrigerants have lower boiling points than other proposed alternatives, which
allows for lower evaporator temperatures needed for certain applications (e.g., blood and
vaccine storage below -40 °C). The commenters also stated that these refrigerants have
low or no glide, which is important for lower-temperature IPR systems using flooded
evaporators (not all of which are chillers). The commenters specified that such
specialized equipment may not have other refrigerants with lower GWPs that are
technically feasible. They also said that requiring high pressure low GWP substitutes,
such as the other refrigerants under consideration in this action, may damage systems.
Therefore, they asserted that HFC-32 and R-454B are the only two low GWP refrigerants
that will perform at the required conditions and above atmospheric pressure in certain
applications. One commenter added that limiting R-454B and HFC-32 refrigerants to
chillers for IPR would amount to imposing use conditions that are contrary to reducing
the “overall risk to human health and the environment” as required under CAA section
612(c). The commenter noted that R-454B and HFC-32 have lower GWPs than many
currently acceptable substances, and suggested approving these two refrigerants broadly
for the IPR sector would help lower environmental impact compared to incumbent
refrigerants in wide use. The commenter also claimed that EPA had not clearly described
how it accounted for the benefits of HFC-32 and R-454B relative to incumbent
refrigerants.
Response: While EPA is not granting the commenters’ request for listing
R-454B and HFC-32 broadly for all IPR, including industrial, medical, and
laboratory applications in IPR, we acknowledge that these refrigerants present
advantages in performance for IPR operating at low temperatures. Therefore,
based on comments received about the technological requirements for IPR to

reach very cold temperatures, EPA is listing HFC-32 and R-454B as acceptable,
subject to use conditions, for IPR, as proposed, with a use condition that provides
for use in IPR chillers. EPA is also making a modification to the proposed use
condition for HFC-32 and R-454B in IPR that would allow for use in non-chiller
IPR with the refrigerant temperature entering the evaporator less than or equal to 30 °C. EPA is achieving this by modifying the use condition for HFC-32 and R454B in IPR, so that it provides for use of HFC-32 and R-454B in both chillers
for industrial process refrigeration and in equipment with the refrigerant
temperature entering the evaporator less than or equal to -30 °C. While R-454B
and HFC-32 have higher GWPs than the other refrigerants being listed as
acceptable in this action, listing these two refrigerants as acceptable with use
conditions that provide for use at lower temperatures still leads to lower risk to the
environment and human health because these refrigerants are lower risk than what
is currently in use.
The Agency is not at this time listing R-454B and HFC-32 as acceptable
in all other IPR uses. We do not agree that commenters have demonstrated that
other lower-risk, lower-GWP options are not available for other non-chiller IPR
uses outside of the lower temperature applications described in their comments.
We also note that upcoming restrictions under the AIM Act’s Technology
Transitions Rule will restrict the GWP of refrigerants used for non-chiller IPR to
150 to 700, depending on the temperature of the refrigerant entering the
evaporator, the refrigerant charge capacity, and whether the refrigerant is used in
the high-temperature side of a cascade system. Thus, regardless of EPA’s
consideration under the CAA SNAP program, R-454B and HFC-32 could not be
used in all IPR applications; their use would be restricted in certain applications
under the AIM Act’s Technology Transitions Rule (88 FR 73098; October 24,

2023).
As noted, in response to comments, EPA is finalizing R-454B and HFC32 as acceptable, subject to use conditions, in non-chiller IPR low temperature
applications, specifically, equipment with the refrigerant temperature entering the
evaporator is less than or equal to -30 °C. These refrigerants have lower boiling
points, as discussed previously in the comparison to other substitutes in this enduse, than the other refrigerants listed in this rule. The Agency recognizes that IPR
equipment is often highly specialized and designed specifically for cooling a
particular industrial process, and that certain specialized applications may require
refrigerants operating at evaporator temperatures of -40 °C or lower. Other,
lower-GWP refrigerants may not be feasible for use in such lower-temperature
applications. EPA further notes that the final Technology Transitions Rule
similarly accommodated lower-temperature IPR applications by establishing a
higher GWP limit for IPR systems with the refrigerant temperature entering the
evaporator less than or equal to -30 °C. 88 FR at 73143.
In response to the comment comparing HFC-32 and R-454B to incumbent
refrigerants, EPA notes that there are other acceptable refrigerants that reduce overall
risks more than both HFC-32 and R-454B and the incumbent refrigerants in most DX
IPR uses, such as ammonia, HCFO-1233zd(E), R-1224yd(Z), R-290, R-471A, and R744. Thus, EPA does not agree with the commenter’s assertion that the use restriction for
this listing for R-454B and HFC-32 increases overall risk to human health and the
environment. Several of these substitutes are non-flammable or are comparable in
flammability to HFC-32 and R-454B, such as ammonia, HCFO-1233zd(E), R-1224yd(Z),
R-471A, and R-744. Most of those refrigerants contain compounds that are not VOC or
are excluded from EPA’s regulatory definition of VOC (see 40 CFR 51.100(s))
addressing the development of SIPs to attain and maintain the NAAQS. Most have an

ozone depletion potential of zero, comparable to HFC-32 and R-454B, with HCFO1233zd(E) and R-1224yd having ODPs of less than 0.0004, and all have a GWP less than
150, compared to R-454B's GWP of 470 and HFC-32's GWP of 675. However, these
lower-GWP refrigerants have boiling points that are too high to use in DX IPR equipment
with the refrigerant temperature entering the evaporator less than or equal to -30 °C (-22
°F), as discussed above in this response.
Comment: One commenter supported EPA’s proposed approval of HFC-32, HFO1234yf, HFO-1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A for
new IPR equipment. The commenter stated that HFC-32, R-454A, and R-454B should be
approved for use in IPR chillers to preserve as many refrigerant options as possible while
navigating changes in equipment design and technology, despite their higher GWPs than
other listed alternatives.
Response: EPA acknowledges the commenter’s support for listing HFC-32, HFO1234yf, HFO-1234ze(E), R-454A, R-454B, R-454C, R-455A, R-57A, and R-516A in this
rulemaking. EPA agrees with the commenter that listing HFC-32, R-454A, and R-454B
will provide more refrigerant options for chillers for IPR while industry navigates
changes in equipment design and technology. EPA is listing HFC-32, HFO-1234yf,
HFO-1234ze(E), R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A for use in
chillers for IPR as proposed, among other things.
Comment: Two commenters suggested changes to the proposal to align with
existing standards for the IPR sector. One commenter stated that very large systems
located in industrial occupancies, refrigeration rooms, or machinery rooms do not fall
under the listing nor installation requirements of UL 60335-2-89. Another commenter
noted that manufacturers adhere to ASHRAE 15, American Society of Mechanical
Engineers (ASME) b31.5, ASME b31.1, or IIAR standards within the IPR sector
depending on the specific application. The commenter requested that EPA consider for

IPR, IPR chillers, and industrial occupancies and allow such alternative standards to
satisfy proposed use conditions where UL 60335-2-89 is not applicable.
Response: EPA agrees with commenters that UL standard 60335-2-89 may not be
appropriate to apply to all equipment in the end-uses listed under this rule in all
situations; EPA has adopted the commenters’ suggestions to reevaluate the applicability
of UL 60335-2-89 for this rulemaking and is finalizing that manufacturers must use
ASHRAE Standard 15 for all occupancies listed in this rule. In cases where UL 60335-289 applies, manufacturers must also follow that standard. It is EPA’s understanding that
UL 60335-2-89 does not apply in machinery rooms, outdoors, or in industrial
occupancies, whereas ASHRAE 15 does apply. Within this rule, industrial occupancies
may apply to IPR or cold storage warehouses Otherwise, we expect manufacturers to do
the due diligence required to reasonably determine whether equipment falls under
categories which are or are not covered by UL 60335-2-89.
Comment: One commenter requested that EPA not finalize a charge size limit use
condition of less than 200 pounds for the listing of R-454A. The commenter stated that
R-454A is a higher capacity and more efficient option than the alternatives with GWPs
less than 150. The commenter stated that energy efficiency is a critical aspect of very
large systems, which may be located in industrial occupancies, refrigeration rooms, or
machinery rooms. The commenter added that EPA’s apparent rationale for the 200
pounds charge capacity use condition was based on a higher GWP than other alternatives.
The commenter felt EPA failed to adequately describe how it evaluated GWP concerns
with other considerations in section 612(c) of the CAA, which requires identification of
alternatives based on an overall reduction in risk to human health and the environment
and an assessment of potentially available technology.
Response: See response in section II.A.6 of this preamble concerning the use
condition limiting use of R-454A to equipment with charge sizes less than 200 pounds.

With regard to EPA’s evaluation of CAA requirements for alternatives to be considered
in light of overall risk reduction and the availability of alternatives, sections II.A.6, II.F.6,
and II.H.3 of this preamble explain the Agency’s evaluation and selection of alternatives.
F. Cold Storage Warehouses—Listing of HFO-1234yf, HFO-1234ze(E), R-454A,
R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in
new cold storage warehouses
This final rule lists HFO-1234yf, HFO-1234ze(E), and the refrigerant blends R454A, R-454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions,
for use in new cold storage warehouses.
Several use conditions required for cold storage warehouses are common to those
required for the other end-uses in this rule. Because of this similarity, EPA discusses the
use conditions that apply to all five end-uses in section II.H of this preamble. In
summary, the common use conditions are: restricting the use of each refrigerant to new
equipment that is specifically designed and clearly marked for that refrigerant; use
consistent with ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions),
including testing, charge sizes, ventilation, usage space requirements, and certain hazard
warnings and markings; and requirements for warning labels and markings on equipment
to inform consumers, technicians, and first responders of potential flammability hazards.
In addition to the common use conditions in section II.H of this preamble, the
following use condition also applies to R-454A in cold storage warehouses: this
substitute may only be used either in equipment with a refrigerant charge capacity less
than 200 pounds or in the high-temperature side of a cascade system.
The regulatory text of the final decisions appears in tables at the end of this
document and is codified in appendix Y to 40 CFR part 82, subpart G. The regulatory
text contains listing decisions for the end-use discussed in this section. EPA notes that
there may be other legal obligations pertaining to the manufacture, use, handling, and

disposal of the refrigerants that are not included in the information listed in the tables
(e.g., the CAA section 608(c)(2) venting prohibition or DOT requirements for transport
of flammable gases). Flammable refrigerants being recovered or otherwise disposed of
from cold storage warehouses are likely to be hazardous waste under RCRA (see 40 CFR
parts 260 through 270).
1. Background on cold storage warehouses
Cold storage warehouses, an end-use within the SNAP program, are refrigerated
warehousing and are used to preserve meat, produce, dairy products, and other perishable
goods prior to their distribution and sale.
Refrigerant choices depend on the refrigerant charge, ambient temperatures and
the temperature required, system performance, energy efficiency, and health, safety and
environmental considerations, among other things. The majority of cold storage
warehouses in the United States use ammonia as the refrigerant in a vapor compression
cycle, although some rely on other refrigerants. In addition to regulations pursuant to the
SNAP program, other Federal or local regulations may also affect refrigerant choice. For
instance, regulations from OSHA may restrict or place requirements on the use of some
refrigerants, such as ammonia. Building codes from local and State agencies may also
incorporate limits on the charge size of particular refrigerants. EPA understands that this
type of equipment may fall under the scope of UL 60335-2-89, “Household and Similar
Electrical Appliances - Safety - Part 2-89: Requirements for Commercial Refrigerating
Appliances and Ice-Makers with an Incorporated or Remote Refrigerant Unit or MotorCompressor” if it is not used in an industrial occupancy and that it always falls under
ASHRAE 15.
EPA is listing HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A as acceptable, subject to use conditions, in new cold storage
warehouses.

2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes the refrigerants for cold storage warehouses in this
section as being in the A2L Safety Group. See section II.A.2 of this preamble for further
discussion on ASHRAE classifications of these refrigerants.
3. What are HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R457A, and R-516A and how do they compare to other refrigerants in the same
end-use?
See section II.A.3 of this preamble for further discussion on the environmental,
flammability, toxicity, and exposure information for HFO-1234yf, HFO-1234ze(E), R454A, R-454C, R-455A, R-457A, and R-516A.67
Redacted submissions and supporting documentation for HFO-1234yf, HFO1234ze(E), and the refrigerant blends are provided in the docket for this rule (EPA-HQOAR-2023-0043) at https://www.regulations.gov. EPA performed risk screening
assessments to examine the health and environmental risks of each of these refrigerants.
These risk screens are available in the docket for this rule.68,69,70,71,72,73,74
Comparison to other substitutes in this end-use: HFO-1234yf, HFO-1234ze(E),
and R-454A, R-454C, R-455A, R-457A, and R-516A all have an ODP of zero,
comparable to or lower than some of the acceptable substitutes in this end-use, such as
ammonia with an ODP of zero and HCFO-1233zd(E) with an ODP less than 0.0004.
HFO-1234yf and HFO-1234ze(E) both have a GWP of one, comparable to that of
EPA previously listed HFO-1234yf as acceptable, subject to use conditions, in motor vehicle AC in lightduty vehicles (74 FR 53445, October 19, 2009), in heavy-duty pickup trucks and complete heavy-duty vans
(81 FR 86778, December 1, 2016) and in nonroad vehicles and service fittings for small refrigerant cans
(87 FR 26276, May 4, 2022). EPA previously listed R-454A, R-454C, and R-457A as acceptable subject to
use conditions as substitutes in residential and light commercial AC and heat pumps (86 FR 24444, May 6,
2021).
68 ICF, 2023s. Op. cit.
69 ICF, 2023t. Op. cit.
70 ICF, 2023u. Op. cit.
71 ICF, 2023w. Op. cit.
72 ICF, 2023x. Op. cit.
73 ICF, 2023y. Op. cit.
74 ICF, 2023z. Op. cit.
HCFO-1233zd(E), CO2, and ammonia with GWPs of 3.7, one, and zero respectively. R454A, R-454C, R-455A, R-457A, and R-516A have GWPs ranging from 140 to 270,
higher than some of the acceptable substitutes for new cold storage warehouses,
including HCFO-1233zd(E), CO2, and ammonia with GWPs of 3.7, one, and zero,
respectively, and lower than those of other acceptable substitutes such as R-450A, R513A, and R-407F with GWPs of about 600, 630, and 1,820, respectively.
Information regarding the toxicity of other available alternatives is provided in the
listing decisions previously made (see https://www.epa.gov/snap/substitutes-coldstorage-warehouses). Toxicity risks of use, determined by the likelihood of exceeding the
exposure limit of HFO-1234yf, HFO-1234ze(E), and the refrigerant blends in these enduses, are evaluated in the risk screens referenced previously. The toxicity risks of using
HFO-1234yf, HFO-1234ze(E), and the refrigerant blends in commercial refrigeration are
comparable to or lower than toxicity risks of other available substitutes in the same enduse. Toxicity risks of the listed refrigerants can be minimized by use consistent with UL
60335-2-89 and ASHRAE 15-2022–which are required by our final use conditions–and
other industry standards, recommendations in the manufacturers’ SDS, and other safety
precautions common in the refrigeration and AC industry.
The flammability risks with HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R455A, R-457A, and R-516A in this end-use, determined by the likelihood of exceeding
their respective LFLs, are evaluated in the risk screens referenced previously. In
conclusion, while these refrigerants may pose greater flammability risk than other
available, non-flammable substitutes in the same end-use, this risk can be minimized by
use consistent with ASHRAE 15-2022 and other industry standards such as UL 60335-289–which is required by the use conditions in this rule– as well as recommendations in
the manufacturers’ SDS and other safety precautions common in the refrigeration and AC
industry. EPA is requiring use conditions to reduce the potential risk associated with the

flammability of these alternatives so that they will not pose greater overall risk to human
health and the environment than other acceptable substitutes in this end-use.
The listed refrigerants provide additional lower-GWP options for situations where
other refrigerants with lower GWPs are not viable, such as for use of ammonia in systems
with remote compressors or in locations where local regulations restrict its use, or where
a lower pressure refrigerant like HCFO-1233zd(E) is not technically viable. Not all
refrigerants listed as acceptable under SNAP will be suitable for the range of equipment
in the cold storage warehouse end-use. To provide additional options to ensure the
availability of refrigerants with lower GWPs for the full range of cold storage warehouses
and, therefore, lower overall risk to human health and the environment, EPA is listing
HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A as acceptable,
subject to use conditions, for use in all types of cold storage warehouses. In addition, to
account for the additional challenges for finding lower-GWP refrigerants for cold storage
warehouses with moderate charge sizes and for cascade systems, EPA is listing R-454A
as acceptable, subject to use conditions, for use in cold storage warehouses with a charge
size capacity less than 200 pounds or for use in the high-temperature side of a cascade
system.
4. Why is EPA finalizing these specific use conditions?
The use conditions in the listings are explained in the preceding paragraphs and in
section II.H.1 of this preamble.
This final rule applies to end-uses covered by UL 60335-2-89, including some
applications in the SNAP cold storage warehouses end-use, e.g., use that is not in
industrial occupancies. In addition, ASHRAE 15-2022 applies to these refrigeration
systems.
UL 60335-2-89 discussed in section II.H of this preamble indicates that
refrigerant charges greater than a specific amount (called “m3” in the standard and based

on the refrigerant’s LFL) should instead be determined using national standards that
apply, such as ASHRAE 15-2022. Hence, EPA is requiring adherence to both standards
as use conditions for cold storage warehouses, with certain exceptions.
EPA is incorporating by reference ASHRAE 15-2022, including all addenda
published by the date of the proposed rule (May 24, 2023), in use conditions that apply to
use of the listed A2L refrigerants in new cold storage warehouses. Where the
requirements specified in this final rule and ASHRAE 15-2022 differ, the requirements of
this final rule apply.
ASHRAE 15-2022 is undergoing continuous maintenance with publication of
periodic addenda and is typically updated and republished every three years. Although
there were additional changes to ASHRAE 15-2022 between issuance of the proposed
rule and now, EPA was not able to review and seek comment on use conditions based on
those more recent changes after publication of the proposal. EPA is therefore not
including addenda or other changes made to ASHRAE 15-2022 after the date of the
proposed rule.
EPA is finalizing as a use condition for the listing of R-454A in cold storage
warehouses that this substitute may only be used either in equipment with a refrigerant
charge capacity less than 200 pounds or in the high-temperature side of a cascade system.
The Agency is finalizing this use condition to allow use of R-454A less broadly than for
the other refrigerants being listed for use in cold storage warehouses because its GWP is
higher than those of the other refrigerants (about 237, compared to one to 150). EPA’s
understanding is that there are two particular situations where use of refrigerants could be
more constrained, and thus, additional refrigerant options that mitigate overall risk to
human health and the environment may be helpful. The first of those situations is in what
the industry standard ASHRAE 15-2022 identifies as a refrigerating system having a
“high probability” that leaked refrigerant from a failed connection, seal, or component

could enter an occupied area. An example of such a constraint is that ASHRAE 15-2022
and UL 60335-2-89 effectively set charge limits for A2L refrigerants to less than 260
times the LFL (approximately 200 pounds for A2L refrigerants and ranging from roughly
120 to 250 pounds for the refrigerants listed in this rule) for applications inside occupied
areas. In contrast, larger charge sizes could be used in “low-probability” locations where
people are unlikely to come in contact with the refrigerant, such as systems used in
industrial occupancies, outdoors or in a machinery room with access restricted to
employees. Where people are unlikely to come into contact with any leaked refrigerant,
there would be fewer space constraints and greater flexibility in equipment design, so
refrigeration system designers can accommodate a narrower set of refrigerants.
Conversely, where people are more likely to come into contact with any leaked
refrigerant in an interior space, which are not industrial occupancies, refrigerant charge
capacities of a system would be less than 200 pounds. In addition, in such public spaces,
there would be more space constraints, less flexibility in equipment design, and
potentially stricter code requirements. EPA recognizes that these may be situations where
R-454A can be used where those other refrigerants cannot, especially where space is
constrained. Therefore, R-454A fills a gap in the stated end-uses where lower-GWP
refrigerant alternatives posing less of a risk to human health and the environment are not
as available, and R-454A’s GWP of approximately 240 and similar toxicity and
flammability profiles would pose lower overall risk to human health and the
environment. Therefore, EPA is listing R-454A as acceptable, subject to use conditions,
only for cold storage warehouses with a refrigerant charge capacity less than 200 pounds.
The second situation where use of refrigerants is likely to be more constrained is
for use in the high-temperature side of cascade systems used for cold storage warehouses.
As discussed in section II.A.1 of this preamble, “Background on retail food
refrigeration,” each side of a cascade system uses a different refrigerant that is most

suitable for the given temperature range. Higher temperature systems, or the “hightemperature side,” have typically used HFCs as a refrigerant; however, it is
technologically achievable and has become more common to use ammonia in the hightemperature side. For lower temperature systems, or the “low temperature side” of the
cascade system, refrigerants with low boiling points such as R-744 can be used.
Considerations for the choice of refrigerant on the high or low temperature side of
cascade systems are influenced by many factors including, but not limited to, a
refrigerant’s toxicity and flammability, its temperature glide, and its suitability to lower
temperature applications. EPA understands that use of flammable or toxic refrigerants,
such as ammonia, on the high-temperature side of a cascade may be limited in certain
circumstances (e.g., based on building codes and/or industry safety standards). EPA notes
that there are multiple substitutes available for the low temperature side of the cascade
system with GWPs lower than that of R-454A. Therefore, EPA is listing R-454A as
acceptable, subject to use conditions, when it is used in the high-temperature side of
cascade systems; this would expand the refrigerant options that can comply with local
building codes and industry safety standards while meeting the more challenging
application of the high-temperature side of a cascade system and satisfying SNAP
considerations of overall risk to human health and the environment.
5. What additional information is EPA including in these listings?
EPA is providing additional information related to these listings. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the substitute under the SNAP program. EPA
encourages users of substitutes to apply all statements in the “Further Information”
column in their use of these refrigerants. See section II.H.2 of this preamble for further
discussion on what additional information EPA is including in these listings.
6. How is EPA responding to comments on cold storage warehouses?

Comment: One commenter supported listing R-454A as acceptable in cold storage
warehouses but recommended that EPA not finalize a charge size limit use condition of
less than 200 pounds for three reasons. First, the commenter stated that R-454A is a
higher capacity and more efficient option than alternatives with GWPs of less than 150.
They stated that given the large energy requirements of cold storage warehouses, energy
efficiency is a critical aspect of these systems. Second, the commenter claimed that many
of these systems are in industrial occupancies, refrigeration rooms, or machinery rooms
and not restricted to the charge limits, listing, and installation requirements defined by
UL 60335-2-89. Third, the commenter stated that EPA failed to adequately describe how
it balanced concerns regarding the GWP of R-454A versus other considerations in section
612(c) of the CAA, which requires identification of alternatives based on an overall
reduction in risk to human health and the environment as well as an assessment of
potentially available technology.
Response: With regard to commenters’ input on a refrigerant charge limit for R454A, see responses in sections II.A.6 and II.H.3 of this preamble concerning the
Agency’s rationale for the condition limiting use of R-454A to equipment with charge
sizes less than 200 pounds. Concerning the energy efficiency of refrigerants for use in
cold storage warehouses, EPA typically does not compare the energy efficiency of
substitutes against each other unless there is a concern that equipment might not be able
to meet DOE’s energy conservation standards with certain substitutes. EPA is not aware
of such concerns for cold storage warehouses. For instance, R-717 is an energy efficient
refrigerant that is commonly used in new cold storage warehouses.
EPA agrees with the commenter that CAA section 612(c) involves considering
the overall risk to human health and the environment of a substitute compared to the
overall risk of other available or potentially available alternatives. In the case of R-454A,
the Agency considered that there are a number of refrigerants also being listed for the

same end-uses, such as HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R516A, and that there are other acceptable refrigerants already listed in the same end-uses,
such as R-717 and R-744, that pose comparable risk to overall human health and the
environment, including similar ODP, low photochemical and insignificant smog impacts
in the lower atmosphere, similar or lower flammability, and exposure levels evaluated to
be below relevant toxicity thresholds, when compared to R-454A. R-454A has a slightly
higher GWP than the other refrigerants listed above. EPA recognizes that there may be
situations where R-454A can be used where those other refrigerants cannot, especially
where space is constrained. Therefore, R-454A fills a gap in the stated end-uses where
lower-GWP refrigerant alternatives posing less of a risk to human health and the
environment are not as available. The situations mentioned by the commenter where the
charge limits of UL 60335-2-89 do not apply are situations where space is not
constrained, such as outdoors or in a machinery room, and therefore, where it is less
critical to use a refrigerant with higher volumetric capacity, such as R-454A. Therefore,
taking into account our overall evaluation of comparative risks, it is appropriate to list R454A for certain equipment, where it is of comparable or lower risk compared to the
currently or potentially available substitutes for that particular equipment and end-use.
Also, concerning comparisons to incumbent refrigerants with higher GWPs than R-454A,
see the responses in sections II.E.6 and II.H.2 of this preamble concerning R-454A in
situations where other refrigerants may not be appropriate for the needs of equipment.
EPA also notes that the 200-pound limit on R-454A in cold storage warehouses is
consistent with a requirement in the final Technology Transitions Rule.
G. Ice Skating Rinks—Listing of HFO-1234yf, HFO-1234ze(E), R-454C, R-455A,
R-457A, and R-516A as acceptable, subject to use conditions, for use in new ice skating
rinks with a remote compressor
This final rule lists HFO-1234yf, HFO-1234ze(E), and the refrigerant blends R-

454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in
new ice skating rinks with a remote compressor.
Several use conditions being finalized for ice skating rinks with a remote
compressor in this rule are common to those finalized for other end-uses in this rule.
Because of this similarity, EPA discusses the use conditions that apply to all five enduses in section II.H of this preamble. For ice skating rinks with remote compressors,
those are the only use conditions EPA is requiring. In summary, the common use
conditions are: restricting the use of each refrigerant to new equipment that is specifically
designed and clearly marked for that refrigerant; use consistent with ASHRAE 15-2022
and with UL 60335-2-89 (with certain exceptions), including testing, charge sizes,
ventilation, usage space requirements, and certain hazard warnings and markings; and
requirements for warning labels and markings on equipment to inform consumers,
technicians, and first responders of potential flammability hazards.
The regulatory text of the decisions appears in tables at the end of this document
and is being codified in appendix Y to 40 CFR part 82, subpart G. The regulatory text
contains listing decisions for the end-use discussed in this section. EPA notes that there
may be other legal obligations pertaining to the manufacture, use, handling, and disposal
of the refrigerants that are not included in the information listed in the tables (e.g., the
CAA section 608(c)(2) venting prohibition or DOT requirements for transport of
flammable gases). Flammable refrigerants being recovered or otherwise disposed of from
ice skating rinks are likely to be hazardous waste under RCRA (see 40 CFR parts 260
through 270).
1. Background on ice skating rinks
Ice skating rinks, an end-use within the SNAP program, include those used by the
general public for recreational purposes and also those for amateur and professional use
(e.g., by professional hockey teams). These systems frequently use secondary loop

refrigeration systems, where a primary loop containing a refrigerant uses a remote
compressor that is in a location away from the public, such as a machinery room, and a
secondary loop, containing propylene glycol, water, or another innocuous fluid, is used to
directly cool the ice. Other types of refrigeration systems for ice skating rinks use a direct
heat exchange system, where the refrigerant moves directly under the rink. The listings
apply only to ice skating rinks that have a remote compressor.
For ice skating rinks, refrigerant choice depends on the refrigerant charge;
ambient temperatures and the temperature required; system performance; energy
efficiency; and health, safety, and environmental considerations, among other things. In
addition to regulations pursuant to the SNAP program, other Federal or local regulations
may also affect refrigerant choice. For instance, regulations from OSHA may restrict or
place requirements on the use of some refrigerants, such as ammonia. Building codes
from local and State agencies may also incorporate limits on the amount of particular
refrigerants used. Acceptable substitutes in use today for new ice skating rinks include
ammonia, CO2, HCFO-1233zd(E) as well as HFCs and HFC/HFO blends. These can be
used alone or in combination with other refrigerants in other parts of the equipment,
depending on the equipment and its design (e.g., a secondary loop contains one
refrigerant while the primary loop contains a different refrigerant). It is EPA’s
understanding that this type of equipment may fall under the scope of UL 60335-2-89,
“Requirements for Commercial Refrigerating Appliances and Ice-Makers with an
Incorporated or Remote Refrigerant Unit or Motor-Compressor” if it is not used in an
industrial occupancy and that it always falls under ASHRAE 15.
2. What are the ASHRAE classifications for refrigerant flammability?
ASHRAE 34-2022 categorizes the refrigerants listed for ice skating rinks in this
section as being in the A2L Safety Group. See section II.A.2 of this preamble for further
discussion on ASHRAE classifications of these refrigerants.

3. What are HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and
R-516A and how do they compare to other refrigerants in the same end-use?
See section II.A.3 of this preamble for further discussion on the environmental,
flammability, toxicity, and exposure information for these refrigerants.
Redacted submissions and supporting documentation for HFO-1234yf, HFO1234ze(E) and the blends R-454C, R-455A, R-457A and R-516A are provided in the
docket for this rule (EPA-HQ-OAR-2023-0043) at https://www.regulations.gov. EPA
performed a risk screening assessment to examine the health and environmental risks of
each of these refrigerants. These risk screens are available in the docket for this
rule.75,76,77,78,79,80
Comparison to other substitutes in this end-use: HFO-1234yf, HFO-1234ze(E),
R-454C, R-455A, R-457A, and R-516A all have an ODP of zero, comparable to or lower
than some of the acceptable substitutes in this end-use, such as ammonia with an ODP of
zero and HCFO-1233zd(E) with an ODP of less than 0.0004.
HFO-1234yf and HFO-1234ze(E) both have a GWP of one, comparable to or
lower than that of other acceptable substitutes for new ice skating rinks, such as
ammonia, CO2, and HCFO-1233zd(E) with GWPs of zero, one, and 3.7, respectively.
R-454C, R-455A, R-457A, and R-516A have GWPs ranging from about 140 to
150 which are higher than that of other acceptable substitutes for ice skating rinks,
including ammonia, CO2, and HCFO-1233zd(E) with GWPs of zero, one, and 3.7,
respectively. The GWPs of HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A,
and R-516A are lower than some of the substitutes acceptable under SNAP for new ice
skating rinks, such as R-450A, and some substitutes currently in use but do not meet the
ICF, 2023s. Op. cit.
ICF, 2023t. Op. cit.
77 ICF, 2023w. Op. cit.
78 ICF, 2023x. Op. cit.
79 ICF, 2023y. Op. cit.
80 ICF, 2023z. Op. cit.
75
GWP limits for use in new ice skating rinks under the Technology Transitions Rule such
as R-449A and R-507A with GWPs of approximately 600, 1,400, and 3,990, respectively.
Information regarding the toxicity of other available alternatives is provided in the
listing decisions previously made (see https://www.epa.gov/snap/substitutes-ice-skatingrinks). Toxicity risks of use, determined by the likelihood of exceeding the exposure limit
of HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A in these enduses, are evaluated in the risk screens referenced previously. The toxicity risks of using
HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A in ice skating
rinks with remote compressors are comparable to or lower than toxicity risks of other
available substitutes in the same end-use. Toxicity risks of the listed refrigerants can be
minimized by use consistent with UL 60335-2-89 and ASHRAE 15-2022–which are
required by our final use conditions–and other industry standards, recommendations in
the manufacturers’ SDS, and other safety precautions common in the refrigeration and
AC industry.
The potential flammability risks of HFO-1234yf, HFO-1234ze(E), R-454C, R455A, R-457A, and R-516A in this end-use, determined by the likelihood of exceeding
their respective LFLs, are evaluated in the risk screens referenced previously. These risk
screens determined that because ice skating rink systems would be installed in locations
with adequate space and/or ventilation in accordance with EPA recommendations and
requirements, industry standards, and the installation and maintenance manuals for
equipment using these refrigerants, significant flammability risk to end-users, personnel,
or the general population is unlikely. In conclusion, while these refrigerants may pose
greater flammability risk than other available substitutes in the same end-use, this risk
can be minimized by use consistent with ASHRAE 15-2022 and other industry standards
such as UL 60335-2-89–which is required by our use conditions–as well as
recommendations in the manufacturers’ SDS and other safety precautions common in the

refrigeration and AC industry. EPA is requiring use conditions to reduce the risk
associated with the flammability of these alternatives so that they will not pose greater
overall risk to human health and the environment than other acceptable substitutes in this
end-use. In addition, EPA is limiting these listings to equipment with a remote
compressor. Such equipment reduces the chances of fire and of exposure to the general
public compared to refrigerants that are piped directly under an ice skating rink.
In addition, the listed substitutes have lower GWPs than most other available
alternatives for the same end-use. The listed refrigerants may provide additional lowerGWP options for situations where other refrigerants with lower GWPs are not viable,
such as in locations where local regulations restrict use of ammonia. Not all refrigerants
listed as acceptable under SNAP will be suitable for the range of equipment in the ice
skating rinks end-use. To provide additional options to ensure the availability of
refrigerants with lower GWPs for ice skating rinks and, therefore, lower overall risk to
human health and the environment, EPA is listing HFO-1234yf, HFO-1234ze(E), R454C, R-455A, R-457A, and R-516A as acceptable, subject to use conditions, for use in
new ice skating rinks.
4. Why is EPA finalizing these specific use conditions?
The final use conditions identified in the listings are explained in section II.H.1 of
this preamble.
This final rule applies to end-uses covered by UL 60335-2-89, including some
applications in the SNAP ice skating rink end-use, e.g., use that is not in industrial
occupancies. In addition, ASHRAE 15-2022 applies to these refrigeration systems.
EPA is incorporating by reference UL 60335-2-89. This standard, as discussed in
section II.H of this preamble, states that refrigerant charges greater than a specific
amount (called “m3” in the standard and based on the refrigerant’s LFL) should instead be
determined using national standards that apply, such as ASHRAE 15-2022. Hence, EPA

is requiring adherence to both standards as use conditions for ice skating rinks, with
certain exceptions.
EPA is incorporating by reference UL 60335-2-89 and ASHRAE 15-2022 in use
conditions that apply to use of the listed A2L refrigerants in new ice skating rinks. Where
the requirements specified in this final rule and ASHRAE 15-2022 differ, the
requirements of this final rule apply.
ASHRAE 15-2022 is undergoing continuous maintenance with publication of
periodic addenda and is typically updated and republished every three years. Although
there were additional changes to ASHRAE 15-2022 between issuance of the proposed
rule and now, EPA was not able to review and seek comment on use conditions based on
those more recent changes after publication of the proposal. EPA is therefore not
including addenda or other changes made to ASHRAE 15-2022 after the date of the
proposed rule.
EPA is finalizing a use condition that the six A2L refrigerants included in this
listing may only be used in new equipment that includes a remote compressor. This is
intended to ensure that these flammable refrigerants are only used away from the
presence of ice skaters and other members of the general public. This would reduce the
likelihood of exposure or leaks of the refrigerant near the general public and instead
allow facility employees and trained technicians to control access to the refrigerant.
5. What additional information is EPA including in these listings?
EPA is providing additional information related to these listings. Since this
additional information is not part of the regulatory decision under SNAP, these
statements are not binding for use of the substitute under the SNAP program. While the
items listed are not legally binding under the SNAP program, EPA encourages users of
substitutes to apply all statements in the “Further Information” column in their use of
these refrigerants. See section II.H.2 of this preamble for further discussion on what

additional information EPA is including in these listings.
6. How is EPA responding to comments on ice skating rinks?
Comment: One commenter requested that EPA include R-454A as an acceptable
refrigerant for ice skating rinks without a 200-pound charge size limit, in alignment with
the proposal’s listing for IPR and cold storage warehouses. The commenter also claimed
that EPA did not provide sufficient explanation why R-454A was unacceptable in this
end-use or why EPA did not to proceed with a filed SNAP petition to find R-454A
acceptable. The commenter stated that EPA must consider all effects contemplated by
CAA section 612(c) and may not only focus on relative GWP in making decisions. The
commenter noted that additional rationale for this determination appears in the docket.
Response: With respect to the comment that EPA must take into account all the
effects contemplated by CAA section 612(c), the Agency responds that it has
appropriately considered these listing decisions, as required by CAA section 612(c) and
EPA’s implementing regulations, including in its consideration of overall risk to human
health and the environment compared to overall risk posed by other available or
potentially available substitutes in the same uses. EPA evaluates not only relative GWP
but all of the criteria for review that are required under the SNAP regulations at 40 CFR
82.180(a)(7) for our comparative risk analysis, including atmospheric effects; general
population risks from ambient exposure to increased ground-level ozone (e.g., volatile
organic compound assessment) or due to direct toxicity of compounds; ecosystem effects
(e.g.; analysis of impacts of breakdown products on aquatic life); flammability risks,
occupational risks (e.g., toxicity of direct exposure to workers or asphyxiation risks), and
consumer risks (e.g., toxicity of exposure to consumers at end-use). These considerations
are reflected in the risk screens found in the docket for this rule and in the discussion
supporting the listing decisions for the listings finalized in this rule. With respect to the
commenter’s reference to a filed SNAP petition to find R-454A acceptable, the Agency

notes that we received a SNAP submission from a manufacturer but is not aware of a
formal petition regarding this refrigerant. EPA did not propose to list R-454A for use in
ice skating rinks, either as acceptable or unacceptable, and is not making a final decision
in the rule regarding whether to list R-454A in this end-use. EPA may consider listing R454A in this or other end-uses in future SNAP listing rules.
H. Use conditions and further information for retail food refrigeration,
commercial ice machines, industrial process refrigeration, cold storage warehouses, and
ice skating rinks with a remote compressor.
1. What use conditions is EPA finalizing and why?
As previously described, EPA is listing:
•

HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A
as acceptable, subject to use conditions, for use in new equipment in
stand-alone units, retail food remote condensing units, supermarket
systems, and refrigerated food processing and dispensing equipment;

•

R-454A as acceptable, subject to use conditions, for use in new
equipment in retail food remote condensing units and supermarket
systems;

•

R-290 as acceptable, subject to use conditions, for use in new refrigerated
food processing and dispensing equipment;

•

HFC-32, HFO-1234yf, R-454A, R-454B, R-454C, R-455A, R-457A, and
R-516A as acceptable, subject to use conditions, for use in new
commercial ice machines;

•

HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, and
R-516A as acceptable, subject to use conditions, for used in new IPR
equipment and HFC-32 and R-454B, as acceptable, subject to use
conditions, for use in new chillers for IPR and in IPR equipment with the

refrigerant temperature entering the evaporator or the temperature of the
exiting fluid less than or equal to -30° C;
•

HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, and
R-516A as acceptable, subject to use conditions, for use in new cold
storage warehouses; and

•

HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A
as acceptable, subject to use conditions, for use in new ice skating rinks
with remote compressors.

In addition, EPA is revising the use conditions that apply to the existing listings
of:
•

R-290 as acceptable, subject to use conditions, for use in new retail food
refrigeration stand-alone units; and

•

R-290 as acceptable, subject to use conditions, for use in new selfcontained commercial ice machines.

The use conditions (either as new listings or revisions to an existing listing)
common to all listing decisions in this rule are: restricting the use of each refrigerant to
new equipment that is specifically designed and clearly marked for the refrigerant; use
consistent with ASHRAE 15-2022 and with UL 60335-2-89 (with certain exceptions),
including testing, charge sizes, ventilation, usage space requirements, and certain hazard
warnings and markings; and requirements for warning labels and markings on equipment
to inform consumers, technicians, and first responders of potential flammability hazards.
Additional specific use conditions are intended to allow for the use of these flammable
refrigerants in a manner that will ensure they do not pose a greater overall risk to human
health and the environment than other substitutes in these end-uses.
New Equipment Only; Not Intended for Use as a Retrofit Alternative
EPA is requiring that these refrigerants be used only in new equipment which has

been designed to address concerns unique to flammable refrigerants. In other words, none
of these refrigerants are being listed as acceptable to be used as a conversion or “retrofit”
refrigerant for existing equipment. EPA is unaware of information on how to address
hazards if these flammable refrigerants were to be used in equipment that was designed
for non-flammable refrigerants. Given the flammable nature of these refrigerants, the fact
that EPA is unaware of information to assess the risk if such retrofits were allowed, and
because the refrigerants were not submitted to the SNAP program for retrofits, EPA has
not reviewed them for retrofit applications and is requiring that they be used only in new
equipment which has been properly designed for their use. This use condition does not
affect the ability to service a system using one of these refrigerants once installed,
including the adding of refrigerant or replacing components.
Standards
To ensure safe use of the listed refrigerants, EPA is incorporating by reference
certain industry consensus safety standards in a use condition. Specifically, the Agency is
requiring that the flammable refrigerants may be used only in equipment that meets
requirements in ASHRAE 15-2022 and in UL 60335-2-89, 2nd edition (with certain
exceptions). Exceptions include equipment that is outside the scope of UL 60335-2-89;
equipment installed in situations where UL 60335-2-89 refers to “national standards”
(e.g., where equipment is installed in a machinery room or outdoors); and equipment
installed in "industrial occupancies," as defined in ASHRAE 15-2022. In the latter
situation, these refrigerants must be used in equipment installed consistent with the
requirements of ASHRAE 15-2022 without meeting the requirements of UL 60335-2-89.
Section 1 of UL 60335-2-89 defines the scope of that standard. It lists both
specific types of equipment that fall under the standard and equipment that falls outside
the scope of the standard. Examples of equipment that are included within the scope of
UL 60335-2-89 include refrigerated display and storage cabinets, refrigerated trolley

cabinets, service counters, factory-assembled walk-in coolers and freezers, refrigerated
food processing and dispensing equipment, commercial refrigeration products with rated
voltage up to 15,000 V, and commercial ice machines. Examples of equipment that fall
outside the scope of UL 60335-2-89 include appliances using flammable refrigerant in
transcritical refrigeration systems, commercial refrigeration products with rated voltage
of 15,000 V or greater, motor compressors, household refrigerating appliances that fall
under the scope of UL 60335-2-24, vending machines, and professional or commercial
ice-cream machines. This final rule does not apply to these types of commercial
refrigeration equipment that fall outside the scope of UL 60335-2-89. Commercial
refrigeration equipment that falls outside the scope of UL 60335-2-89 in situations where
UL 60335-2-89 refers to “national standards” is still required to meet ASHRAE 15-2022
under this final rule. ASHRAE 15-2022 enforces, rather than replaces, UL 60335-2-89,
by providing instructions for installation of equipment and requirements for situations
beyond the scope of UL 60335-2-89, e.g., for use in refrigeration systems with large
charge sizes in a machinery room or outdoors.
Under the existing SNAP listings, new stand-alone units using R-290 have been
subject to a use condition to meet the requirements of Appendix SB of the 10th edition of
UL 471. In this final action, stand-alone units using R-290 manufactured before the
effective date may continue to be used under SNAP and will remain in compliance with
the existing SNAP use conditions as long as they meet the applicable use conditions
when they were manufactured. New stand-alone units using R-290 manufactured from
the effective date of this final rule through September 29, 2024, must meet the
requirements of either Appendix SB of the 10th edition of UL 471 or UL 60335-2-89,
dependent upon which standard they were certified, to comply with the use conditions
established in this final action. Similarly, new stand-alone units using R-290 that are
manufactured on or after September 30, 2024, must meet the requirements of UL 60335-

2-89, rather than the earlier UL standards, unless the new stand-alone units remain
essentially unchanged from an earlier model or design that was already UL-listed to the
earlier UL 471 standard.
Similarly, under the use conditions in the existing SNAP listings, new selfcontained commercial ice machines using R-290 have been subject to the requirements of
Appendix SA of the 8th edition of UL 563. In this final action, commercial ice machines
using R-290 manufactured before the effective date of this final rule may continue to be
used under SNAP and will remain in compliance with the SNAP use conditions as long
as they met the applicable use conditions when they were manufactured. New selfcontained commercial ice machines using R-290 that are manufactured from the effective
date of this final rule through September 29, 2024, must meet the requirements of either
Appendix SA of the 8th edition of UL 563 or UL 60335-2-89, contingent upon which
standard the equipment was designed, to comply with the use conditions established in
this final action. Similarly, new self-contained commercial ice machines using R-290 that
are manufactured on or after September 30, 2024, must meet the requirements of UL
60335-2-89, rather than the earlier UL standards, unless the new stand-alone units remain
essentially unchanged from an earlier model or design that was already UL-listed to the
earlier UL 563 standard.
UL 60335-2-89 includes requirements for construction and system design, for
markings, and for performance tests concerning refrigerant leakage, ignition of switching
components, surface temperature of parts, and component strength after being scratched.
UL 60335-2-89 was developed through an open and consensus-based approach, with the
assistance of experts in the AC and refrigeration industry as well as experts involved in
assessing the safety of products. Those participating in the UL 60335-2-89 consensus
standards process have tested equipment for flammability risk and evaluated the relevant
scientific studies. While similar standards exist from other bodies such as the

International Electrotechnical Commission (IEC), we are relying on specific UL
standards that are most applicable and recognized by the U.S. market. This approach is
the same as that in our previous listing determinations for flammable refrigerants (e.g., 76
FR 78832, December 20, 2011; 80 FR 19454, April 10, 2015; 86 FR 24444, May 6,
2021; and 87 FR 45508, July 28, 2022).
A summary of the requirements of the 2nd edition of UL 60335-2-89 as they affect
the listed refrigerants and end-uses is offered here for information only and does not
provide a complete review of the requirements in this standard. Please consult the
standard itself for additional information.
The requirements in UL 60335-2-89 reduce the risk to workers and consumers
posed by flammable refrigerants. UL 60335-2-89 limits the amount of refrigerant allowed
in each type of appliance based on several factors explained in that standard. The
standard specifies requirements for installation space of an appliance (e.g., room floor
area) and/or ventilation or other requirements that are determined according to the
refrigerant charge used in the appliance, the installation location, and the type of
ventilation of the location or of the appliance. UL 60335-2-89 contains provisions for
safety mitigation when using larger charges of A2L refrigerants or when using A2L
refrigerants in equipment with a remote compressor. These mitigation requirements were
developed to ensure the safe use of flammable refrigerants over a range of appliances. In
general, as larger charge sizes are used, more stringent mitigation measures are required.
In certain applications, refrigerant detection systems (as described in Annex 101.DVP,
Refrigerant detection systems for A2L refrigerants); means of mitigation (as described in
Annex 101.DVU, including air circulation, ventilation, shut off valves, etc.); and
refrigerant sensors (as described in 101.DVP, Refrigerant sensor for REFRIGERANT
DETECTION SYSTEMS) are required. Where air circulation (e.g., fans) is required in
accordance with Annex 101.DVU, it must be initiated by a separate refrigerant detection

system either as part of the appliance or installed separately. In a room with no
mechanical ventilation, Annex 101.DVU1.7 provides requirements for openings to rooms
based on several factors, including the charge size and the room area. The minimum
opening is intended to be sufficient so that natural ventilation would reduce the risk of
using a flammable refrigerant. The standard also includes specific requirements covering
construction, instruction manuals, allowable charge sizes, mechanical ventilation, safety
alarms, and shut off valves for A2L refrigerants.
In addition to Annex 101.DVU, UL 60335-2-89 has a requirement for the
maximum charge for an appliance using a flammable refrigerant, including A2L, A2, and
A3 refrigerants. Additional requirements exist for charge sizes exceeding three times the
LFL.
Systems with refrigerant charges exceeding certain amounts are outside the scope
of UL 60335-2-89; however, national standards apply instead, namely, ASHRAE 152022. Specifically, for a field-charged system, if the refrigerant circuit with the greatest
mass of an A2L refrigerant contains more than 260 times the LFL (in kg/m3), such a
refrigerant circuit can only be used outdoors or in a machinery room where the
requirements of ASHRAE 15-2022 apply. For example, HFC-32 has an LFL of
approximately 0.307 kg/m3 (0.0192 lb/ft3); therefore, a single refrigerant circuit
exceeding 79.82 kg (176.0 lb) would fall outside the scope of UL 60335-2-89. In such
situations, the refrigerant circuit would need to be used in outdoor equipment or in a
machinery room and the installation would need to meet the requirements of ASHRAE
15-2022. For self-contained equipment using an A3 refrigerant, the maximum charge size
is 13 times the LFL (approximately 500 g of R-290) for equipment that is open and
contains no doors or drawers and eight times the LFL (approximately 300 g of R-290) for
equipment with doors or drawers. EPA expects that many types of retail refrigeration
equipment could exceed these charge thresholds and therefore is finalizing that an

additional safety standard, ASHRAE 15-2022, apply to commercial refrigeration
equipment using flammable refrigerants, as discussed in section II.A of this preamble.
ASHRAE 15-2022 supplements, rather than replaces, UL 60335-2-89, by providing
instructions for installation of equipment and requirements for situations beyond the
scope of UL 60335-2-89. In addition, ASHRAE 15-2022 refers to some spaces as
“industrial occupancies,” in which refrigerating systems must follow ASHRAE 15-2022
and businesses may have custom-designed refrigeration equipment that has not typically
been designed to meet UL standards for products. ASHRAE 15-2022 defines “industrial
occupancies” as “a premise or that portion of a premise that is not open to the public,
where access by authorized persons is controlled, and that is used to manufacture,
process, or store goods such as chemicals, food, ice, meat, or petroleum.” Many, but not
all, spaces where IPR equipment, cold storage warehouses, and ice skating rink systems
are used qualify as industrial occupancies.
Under the existing SNAP listings, new stand-alone units using R-290 have been
subject to a use condition to meet the requirements of Appendix SB of the 10th edition of
UL 471. In this final action, stand-alone units using R-290 manufactured before the
effective date may continue to be used under SNAP and will remain in compliance with
the existing SNAP use conditions as long as they meet the applicable use conditions
when they were manufactured. New stand-alone units using R-290 manufactured from
the effective date of this final rule through September 29, 2024, must meet the
requirements of either Appendix SB of the 10th edition of UL 471 or UL 60335-2-89 to
comply with the use conditions established in this final action. Similarly, new stand-alone
units using R-290 that are manufactured on or after September 30, 2024, must meet the
requirements of UL 60335-2-89, rather than the earlier UL standards, unless the new
stand-alone units remain essentially unchanged from an earlier model or design that was
already UL-listed to the earlier UL 471 standard.

Similarly, under the existing SNAP listings, new self-contained commercial ice
machines using R-290 have been subject to the requirements of Appendix SA of the 8th
edition of UL 563. In this final action, commercial ice machines using R-290
manufactured before the effective date of this final rule may continue to be used under
SNAP and will remain in compliance with the SNAP use conditions as long as they met
the applicable use conditions when they were manufactured. New self-contained
commercial ice machines using R-290 that are manufactured from the effective date of
this final rule through September 29, 2024, must meet the requirements of either
Appendix SA of the 8th edition of UL 563 or UL 60335-2-89 to comply with the use
conditions established in this final action. Similarly, new self-contained commercial ice
machines using R-290 that are manufactured on or after September 30, 2024, must meet
the requirements of UL 60335-2-89, rather than the earlier UL standards, unless the new
stand-alone units remain essentially unchanged from an earlier model or design that was
already UL-listed to the earlier UL 471 standard.

Warning Labels—Equipment with A2L refrigerants
EPA is requiring labeling of refrigerating systems used in retail food refrigeration
equipment, commercial ice machines, IPR equipment, cold storage warehouses, and ice
skating rinks (“equipment”) containing the listed lower flammability (A2L) refrigerants.
The text of these labels can also be found in Annex 101.DVV of UL 60335-2-89.
References to “the UL standard” below are to UL 60335-2-89, 2nd edition. The following
labels, or the equivalent, must be provided in letters no less than 6.4 mm (¼ inch) high
and must be permanent:
1. On the outside of the unit: “WARNING—Risk Of Fire. Flammable Refrigerant Used.
To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant
Tubing”
2. On the outside of the equipment: “WARNING—Risk of Fire. Dispose of Properly In

Accordance With Federal Or Local Regulations. Flammable Refrigerant Used”
3. On the inside of the equipment near the compressor: “WARNING—Risk of Fire.
Flammable Refrigerant Used. Consult Repair Manual/Owner’s Guide Before Attempting
to Service This Product. All Safety Precautions Must Be Followed”
4. For any equipment pre-charged at the factory, on the equipment packaging or on the
outside of the equipment: “WARNING—Risk of Fire due to Flammable Refrigerant
Used. Follow Handling Instructions Carefully in Compliance with National Regulations”
a. If the equipment is delivered packaged, this label shall be applied on the
packaging
b. If the equipment is not delivered packaged, this label shall be applied on the
outside of the appliance.
EPA expects that all stand-alone units, self-contained commercial ice machines, and
self-contained refrigerated food processing and dispensing equipment would be
packaged, and hence this label would be placed as stipulated in item a above. EPA
expects that other types of commercial refrigeration equipment could be provided
packaged or not, and this label would be placed as stipulated in item a or b, respectively.
5. On indoor unit near the nameplate:
a. At the top of the marking: “Minimum installation height, X m (W ft)”. This
marking is only required if the similar marking is required by UL 60335-2-89. The terms
“X” and “W” shall be replaced by the numeric height as calculated per the UL Standard.
Note that the formatting here is slightly different than the UL Standard; specifically, the
height in Inch-Pound units is placed in parentheses and the word “and” has been replaced
by the opening parenthesis.
b. Immediately below 5.a or at the top of the marking if 5.a is not required:
“Minimum room area (operating or storage), Y m2 (Z ft2)”. The terms “Y” and “Z” shall
be replaced by the numeric floor area as calculated per the UL Standard. Note that the

formatting here is slightly different than the UL Standard; specifically, the area in InchPound units is placed in parentheses and the word “and” has been replaced by the
opening parenthesis.
6. For non-fixed equipment, including on the outside of the appliance: “WARNING—
Risk of Fire or Explosion—Store in a well-ventilated room without continuously
operating flames or other potential ignition.”
7. For fixed equipment that is ducted, near the nameplate: “WARNING—Risk of Fire—
Auxiliary devices which may be ignition sources shall not be installed in the ductwork,
other than auxiliary devices listed for use with the specific appliance. See instructions.”
Labeling requirements 1, 2, and 3 apply to all refrigeration equipment; labeling
requirement 4 applies only to self-contained equipment that is pre-charged by the
manufacturer (e.g., stand-alone units or self-contained commercial ice machines);
labeling requirement 5 applies to equipment with a remote compressor, also called a
“split” or “remote” system (e.g., remote condensing unit, supermarket system, or
refrigerating system for an ice skating rink with a remote compressor). A piece of
refrigeration equipment that may be moved from one location to another and is typically
self-contained is referred to as “non-fixed” in labeling requirement 6 (e.g., stand-alone
units).
EPA notes that Annex 101.DVV of UL 60335-2-89 specifies that the labels must
include text with a font size that is no less than 3.2 mm (1/8 inch) high for A2L
refrigerants, while the Agency is requiring a larger, more visible font size of 6.4 mm (1/4
inch). The Agency is concerned that it is difficult to see warning labels with the minimum
lettering height requirement of 1⁄8 inch in UL 60335-2-89. Therefore, as in the
requirements in our previous rules for use of A2L refrigerants in residential and light
commercial air conditioning and heat pumps (80 FR 19453, April 10, 2015; 86 FR
24444, May 6, 2021), as well as our previous rules for HC refrigerants (76 FR 78832,

December 20, 2011; 80 FR 19453, April 10, 2015; 81 FR 86778, December 1, 2016),
EPA is requiring that the minimum height for lettering be 1⁄4 inch as opposed to 1⁄8 inch.
This will make it easier for technicians, consumers, retail storeowners, and first
responders to view the warning labels.
Warning Labels—Equipment with A3 refrigerants, including R-290
As a final use condition for refrigerated food processing and dispensing
equipment and a revision to existing use conditions for stand-alone units and commercial
ice machines, EPA is requiring labeling of such equipment containing R-290. The text of
these labels can also be found in Annex 101.DVV of UL 60335-2-89. References to “the
UL standard” below are to UL 60335-2-89. The following markings, or the equivalent,
must be provided in letters no less than 6.4 mm (¼ inch) high and must be permanent:
1. On the outside of the unit: “DANGER”—Risk Of Fire Or Explosion. Flammable
Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture
Refrigerant Tubing”
2. On the outside of the equipment: “WARNING—Risk of Fire or Explosion. Dispose of
Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant
Used”
3. On the inside of the equipment near the compressor: “DANGER—Risk Of Fire or
Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner’s Guide Before
Attempting to Service This Product. All Safety Precautions Must Be Followed”
4. For any equipment pre-charged at the factory, on the equipment packaging or on the
outside of the equipment: “DANGER—Risk of Fire or Explosion due to Flammable
Refrigerant Used. Follow Handling Instructions Carefully in Compliance with National
Regulations”
a. If the equipment is delivered packaged, this label shall be applied on the
packaging

b. If the equipment is not delivered packaged, this label shall be applied on the
outside of the appliance
EPA expects that all stand-alone units and self-contained commercial ice machines
and self-contained refrigerated food processing and dispensing equipment would be
packaged, and hence this label would be placed as stipulated in item a above. EPA
expects that other types of commercial refrigeration equipment could be provided
packaged or not, and this label would be placed as stipulated in item a or b, respectively.
5. On indoor unit near the nameplate:
a. At the top of the marking: “Minimum installation height, X m (W ft)”. This
marking is only required if the similar marking is required by UL 60335-2-89. The terms
“X” and “W” shall be replaced by the numeric height as calculated per the UL Standard.
Note that the formatting here is slightly different than the UL Standard; specifically, the
height in Inch-Pound units is placed in parentheses and the word “and” has been replaced
by the opening parenthesis.
b. Immediately below 5.a or at the top of the marking if 5.a is not required:
“Minimum room area (operating or storage), Y m2 (Z ft2)”. The terms “Y” and “Z” shall
be replaced by the numeric area as calculated per the UL Standard. Note that the
formatting here is slightly different than the UL Standard; specifically, the area in InchPound units is placed in parentheses and the word “and” has been replaced by the
opening parenthesis.
6. For non-fixed equipment, including on the outside of the appliance: “WARNING—
Risk of Fire or Explosion—Store in a well-ventilated room without continuously
operating flames or other potential ignition.”
7. For fixed equipment that is ducted, near the nameplate: “WARNING—Risk of Fire or
Explosion—Auxiliary devices which may be ignition sources shall not be installed in the
ductwork, other than auxiliary devices listed for use with the specific appliance. See

instructions.”
The text of the warning labels is exactly the same as that required in UL 60335-289, with the exception of the label identified in 5, which is similar to but slightly different
from that in UL 60335-2-89. The text for A3 refrigerants differs slightly from that for
A2L refrigerants, sometimes using the word “DANGER” instead of “WARNING,” and
sometimes referring to “Risk of Fire or Explosion” instead of “Risk of Fire.” For R-290
and other A3 refrigerants, UL 60335-2-89 requires the labels to be no less than 6.4 mm
(1/4 inch) high in the standard, the same as EPA is requiring in this action.
Markings
EPA is requiring as a use condition that the refrigerants must be used in
refrigerating equipment that has red, Pantone® Matching System (PMS) #185 or RAL
3020 marked pipes, hoses, and other devices through which the refrigerant is serviced,
typically known as the service port, to indicate the use of a flammable refrigerant. This
color must be present at all service ports and where service puncturing or otherwise
creating an opening from the refrigerant circuit to the atmosphere might be expected
(e.g., process tubes). The color mark must extend at least 2.5 centimeters (1 inch) from
the compressor and must be replaced if removed. EPA has applied this same use
condition in past actions for flammable refrigerants (76 FR 78832, December 20, 2011;
80 FR 19454, April 10, 2015; 81 FR 86778, December 1, 2016; 86 FR 24444, May 6,
2021; and 87 FR 45508, July 28, 2022). Our understanding of UL 60335-2-89 is that red
markings similar to those finalized are required by UL 60335-2-89 for all flammable
refrigerants. EPA is requiring that such markings apply through the SNAP use conditions
as well to establish a common, familiar, and standard means of identifying the use of a
flammable refrigerant.
These red markings allow technicians to immediately identify the use of a
flammable refrigerant, thereby reducing the risk of using sparking equipment or

otherwise having an ignition source nearby. It also provides adequate notification of the
presence of flammable refrigerants for personnel disposing of appliances containing
flammable refrigerants. The AC and refrigeration industry currently uses red-colored
hoses and piping as means for identifying the use of a flammable refrigerant based on
previous SNAP listings and some industry standards. Likewise, distinguishing coloring
has been used elsewhere to indicate an unusual and potentially dangerous situation, for
example in the use of orange-insulated wires in hybrid and electric vehicles. Currently in
SNAP listings, color-coded hoses or pipes must be used for ethane, HFC-32, R-452B, R454A, R-454B, R-454C, R-457A, R-600a, R-290, and R-441A in equipment wherever
these are listed acceptable, subject to use conditions. All such tubing must be colored red
PMS #185 or RAL 3020. As explained in SNAP Rule 19, one mechanism to distinguish
hoses and pipes is to add a colored plastic sleeve or cap to the service tube (80 FR 19465,
April 10, 2015). Other methods, such as a red-colored tape, may be used. The colored
plastic sleeve, cap, or tape must have to be forcibly removed to access the service tube
and must be replaced if removed. This sleeve, cap, or tape would be of the same red color
(PMS #185 or RAL 3020) and could also be boldly marked with a graphic to indicate the
refrigerant was flammable. This could be a cost-effective alternative to painting or dyeing
the hose or pipe.
EPA is requiring the use of color-coded hoses or piping in addition to requiring
the use of warning labels discussed previously. Having two warning methods is
reasonable and consistent with other general industry practices. This approach is the same
as that adopted in our previous rules on flammable refrigerants (e.g., 76 FR 78832,
December 20, 2011; 80 FR 19454, April 10, 2015; 86 FR 24444, May 6, 2021; and 87 FR
45508, July 28, 2022).
EPA proposed a diamond symbol for “Caution, risk of fire” that would be used in
addition to the red triangle in Clause 7.6DV D1 of UL 60335-2-89. After considering

public comments, EPA is not finalizing a requirement for the diamond symbol in this rule
(see section II.H.3 of this preamble). However, manufacturers will be required to place
either the red triangle symbol described in UL 60335-2-89, 2nd edition, or the red
diamond symbol that was proposed (for more information, see section II.H.3 of this
preamble), or both.
For those that choose to comply with fire hazard marking in this rule by using the
red-bordered diamond, refer to the symbol which has been finalized for hazard category 1
flammable gases in the docket for this rulemaking under the title, “Final Flammability
Hazard Symbol.” This symbol is included as the warning symbol for hazard category 1
flammable gases in the 9th edition of the GHS for communicating risks of chemicals. This
symbol for hazard category 1 flammable gases is included in the 4th edition of UL 60335–
2–40 (December 2022), UL's most recent safety standard for air conditioning equipment,
heat pumps, and humidifiers, and is being considered for adoption in the future 3rd edition
of UL 60335–2–89. It is found in section 1.2 of Annex 1 of the 9th edition of the GHS.
For those that choose to comply with fire hazard markings in this rule by using
the red-bordered diamond, this marking shall be placed near the service port or other
location where charging occurs; on the label on the outside of the unit; and either on the
appliance packaging, if the refrigeration equipment is charged at the factory or on the
nameplate or control panel for the refrigeration equipment that is charged in place. These
locations correspond with the locations for red markings and for labels 1 and 4 mentioned
above on the outside of the refrigerating unit, and either on the packaging or on the
nameplate or control panel. If used, the diamond symbol for hazard category 1 flammable
gases needs to be at least 15 mm (9/16 inches high). The Agency notes that it may
propose to require the adoption of this symbol in a future rulemaking when a new edition
of UL 2-89 is released.
2. What additional information is EPA including in these listings?

For retail food refrigeration, commercial ice machines, IPR, cold storage
warehouses, and ice skating rinks with remote compressors, EPA is including
recommendations, found in the “Further Information” column of the regulatory text, to
protect personnel from the risks of using flammable refrigerants. Similar to our previous
listings of flammable refrigerants, EPA is including information on the OSHA
requirements at 29 CFR part 1910, proper ventilation, personal protective equipment, fire
extinguishers, use of spark-proof tools and equipment designed for flammable
refrigerants, and training. Since this additional information is not part of the regulatory
decision under SNAP, these statements are not binding for use of the substitute under the
SNAP program. While the items listed are not legally binding under the SNAP program,
EPA encourages users of substitutes to apply all statements in the “Further Information”
column in their use of these refrigerants.
3. How is EPA responding to comments on use conditions?
Comment: Four commenters suggested clarifications surrounding manufacturers’
use of R-290 in self-contained products (150 grams or less). The commenters stated that
the proposal references a sunset of UL 471. They noted that UL will allow manufacturers
to continue under UL 471 and UL 563 requirements until a significant product change is
made or the manufacturer withdraws their file. The commenters stated that only at that
time will R-290 equipment become subject to 60335-2-89. They asked for EPA to clarify
this in the final rule.
Response: EPA thanks the commenters for bringing to our attention that UL
allows manufacturers to continue manufacturing equipment under UL 471 or UL 563
requirements until a significant product change is made or the manufacturer withdraws
their UL listing file. As discussed above, certain listings in this final rule include an
option for new equipment using R-290 to be manufactured according to UL 471 and UL
563 if certain criteria are met. Further, we note that UL 471, UL 563, and UL 60335-2-89

all address the potential hazards of using flammable refrigerants. Thus, these listings
include options for new equipment to meet any of these standards, provided that, for UL
471 or 563, the equipment or model was designed and UL-listed according to one of
those standards before the sunset date of UL 471 or UL 563.
Comment: Six commenters requested that EPA align its proposal with regard to
existing safety standards for A2Ls and other flammable refrigerants. These commenters
noted that for the end-uses in the proposal ASHRAE 15 is the appropriate standard, with
UL 60335-2-89 only applicable in certain end-uses. They noted that equipment is built to
ASHRAE 15, B31.5 or B31.3, National Electrical Code (NEC) and possibly IIAR
standards; therefore, compliance with UL 60335-2-89 for these end-uses could create
conflict within the industry.
Several commenters stated there was misalignment in standards and the proposal
for specific end-uses. Three commenters noted that for systems located in industrial
occupancies, ASHRAE 15 states these locations do not have to be listed to UL 60335-289 and charge limits do not apply. These commenters stated that some IPR, IPR chiller,
cold storage warehouse, and ice skating rink applications located in industrial
occupancies would fall outside the scope of UL 60335-2-89. For IPR chillers, a different
commenter stated that the application of UL 60335-2-89 is sufficient to mitigate the risks
posed by the use of A2L refrigerants because of the requirements for preventing ignition
of A2L refrigerants from electrical parts/devices and hot surfaces, the detection system
for A2L refrigerants, the manual of operation, service, and installation, the warning labels
and markings, and the competence of personnel. Four commenters noted that professional
ice cream appliances are specifically excluded from the scope of UL 60335-2-89, and that
this equipment follows UL 621, which has not been updated to allow for use of
flammable refrigerants. One commenter added that for SNAP 26 to apply to ice cream
machines the use conditions must include UL 621 and 60335-2-89.

Response: EPA agrees with the commenters that ASHRAE 15 is an applicable
standard to all the end-uses in this rule, with UL 60335-2-89 applicable to certain
applications in the end-uses of this rule. UL 60335-2-89 should be followed where
applicable in addition to the standard requirements under ASHRAE 15. Based on EPA’s
review of UL 60335-2-89 and conversations with UL, it is EPA’s understanding that
some IPR, IPR chiller, cold storage warehouse, and ice skating rink applications located
in industrial occupancies have not followed UL 60335-2-89 and instead have followed
ASHRAE 15. After considering all the public comments on the proposal, we are
finalizing use conditions requiring ASHRAE 2022-15 for all substitutes listed in this rule
and UL 60335-2-89 where it applies, as use conditions for refrigerants in the end-uses
covered by this rulemaking, with modifications in response to the comments received. In
particular, the final regulatory text requires that 1) ASHRAE 15-2022 applies in all cases
and 2) UL 60335-2-89 applies, with exceptions for equipment that is outside the scope of
UL 60335-2-89, equipment installed in situations where that standard refers to “national
standards,” (i.e., ASHRAE 15), and for the flammability marking identified in in Clause
7.6DV D1 of UL 60335-2-89 (where the equipment must display either or both of the red
triangle or red bordered diamond symbol). To allow for better alignment with the two
industry standards, EPA has revised the regulatory text concerning UL 60335-2-89 to
state, “These refrigerants may only be used in refrigeration equipment that meets all
requirements in UL 60335-2-89, except as provided otherwise in UL 60335-2-89, in
ASHRAE 15, or in this listing.” EPA agrees with the commenters that equipment for
professional (i.e., not household or consumer) ice cream appliances is not covered by UL
60335-2-89 and instead follows UL 621, Ice Cream Makers; and as such, ice cream
appliances are not covered by this rulemaking. EPA has revised the regulatory text to
state that the listings for refrigerated processing and dispensing equipment do not apply
to refrigerated processing and dispensing equipment that is within the scope of UL 621

(Ice Cream Makers).
Determining the coverage of UL standards to applications not covered in this rule
is outside the scope of this rulemaking. New equipment covered by the end-uses in this
rule must comply with ASHRAE 15 in all instances, and with UL 60335-2-89 where
applicable. Further, EPA is allowing for exceptions from the requirement to meet UL
60335-2-89 for equipment that falls outside that standard’s scope, which means that
commercial or professional ice cream makers are not required to meet that standard. As
described in NOTE 103 in UL 60335-2-89, “This standard does not apply to…
–Appliances using flammable refrigerant in transcritical refrigeration systems;
– domestic refrigerating appliances (IEC 60335-2-24);
– motor-compressors (IEC 60335-2-34);
– vending machines (IEC 60335-2-75);
– professional ice-cream appliances (IEC 60335-2-118);
– laboratory refrigerators and freezers (for Canada only. In Canada, the applicable
standard for laboratory refrigerators and freezers is CSA C22.2 No. 61010-2-011.)”
Comment: Three commenters requested that EPA clarify the terminology in the
proposal, noting that both ASHRAE 15 and UL 60335-2-89 use the term “releasable
charge” where EPA used the term “refrigerant charge.” To ensure alignment and
minimize confusion, they asked EPA to amend the appropriate terminology used in
ASHRAE 15 and UL 60335-2-89 standards. One commenter elaborated that the
“releasable charge” is how much refrigerant can be leaked into the space, which could be
all of the charge for small systems or the remaining refrigerant after a refrigerant detector
identifies a leak and causes safety solenoids to close and isolate refrigerant in larger
systems. Similarly, two of these commenters noted that ASHRAE and EPA rely on a
different definition of “independent circuit” and asked EPA to align its proposal with the
ASHRAE definition.

Response: EPA has clarified the term “releasable charge” in the final risk screens
supporting this rule, including amended scenarios with this measure where appropriate.
EPA notes that the releasable charge may be used to calculate the maximum allowable
charge for each unit or system to which UL 60335-2-89 and/or ASHRAE 15 applies.
EPA agrees with the commenter that the releasable charge is the maximum quantity of
refrigerant that could be released or leaked into the space. However, we are retaining the
proposed term “refrigerant charge capacity” in this rule when referring to charge size
limits in the use conditions for R-454A. The charge size capacity is easily determined by
looking at the nameplate for refrigeration equipment, allowing for ease of determining
compliance and of enforcing regulations. Further, this allows for consistency with
limitations in the 2023 Technology Transitions Rule, reducing confusion for the regulated
community.
Regarding the comment on the definition of “independent circuit,” EPA used the
term “refrigerant circuit” in the proposed rule and did not use the term “independent
circuit.” The Agency has used the term “refrigerant circuit” in previous SNAP
regulations concerning flammable refrigerants, as well. ASHRAE’s definition of
“independent circuit” is “a closed refrigeration circuit that is arranged in such a manner
that, in the event of a single point of failure, the release of refrigerant is limited to only
the quantity contained within the refrigeration circuit.” EPA recognizes that the definition
of “independent circuit” is consistent with the concept of releasable charge. It is not clear
from the comments in which situations the commenters thought that the Agency should
be using ASHRAE’s term “independent circuit.” However, in response, in this preamble
to the final rule, EPA is clarifying that the charge size or releasable charge requirements
apply to each independent circuit. For example, for a cascade system, each of the circuits
is independent of the others, and the charge limits apply to individual circuits, not to the
entire cascade system.

Comment: Five commenters flagged inconsistencies with regard to the charge
sizes mentioned in the proposal. These commenters noted that UL 60335-2-89 allows
compressor units, condensing units, and condenser units containing a refrigerant charge
over m3 (260 times the LFL) in a machinery room or outdoors in compliance with
ASHRAE 15; meaning that this part of the system can exceed 260 times the LFL, if
installed in a machinery room or outdoors with additional charge of refrigerant allowed in
parts of the system entering an indoor space. One of these commenters provided more indepth comments detailing specific passages and annexes within the standard for EPA
reference. One commenter noted that there is work ongoing between ASHRAE and UL to
align requirements and provide clarity as to if just the condensing unit, compressor unit,
or evaporating unit must be in a machine room or outdoors (as per UL), or if all
refrigerant containing parts must be in a machine room (as per ASHRAE).
Response: EPA thanks the commenters for bringing to our attention the
inconsistencies regarding charge sizes mentioned in the proposal as it relates to industry
standards and the ongoing work to align those standards. EPA agrees with the
commenters that the UL 60335-2-89 standard allows charge over m3 (260 times the LFL)
for equipment located in a machinery room or outdoors in compliance with ASHRAE 15.
In response to these comments, EPA has edited this language in the final rule by stating
in each listing that “These refrigerants may only be used in refrigeration equipment that
meets all requirements in UL 60335-2-89,1,2,3 except as provided otherwise in UL 603352-89, in ASHRAE 15-2022, or in this listing…”
Comment: Several commenters referenced industry standards with regard to
specific refrigerants. A commenter asked that EPA not allow refrigerant charge limits
that exceed U.S. industry safety standards, noting that the table in Appendix R lists HFC32, R-290, and R-441A as “Acceptable subject to use conditions,” with refrigerant charge
limits of 1,000 g, 300 g, or 330 g. However, they asserted that U.S. industry safety

standards, such as UL 484, UL 60335-2-40, and ASHRAE 15, do not allow these charge
limits. Another commenter generally supported the use of UL 60335-2-89 but noted that
the LFL for R-455A was incorrect in the standard’s 2nd edition (0.317 kg/m3) while the
3rd edition of UL 60335-2-89 contains the correct LFL value (0.432 kg/m3). The
commenter noted that using the value from the 2nd edition could result in a reduction of
allowable charge sizes for R-455A. They suggested EPA refer to the LFL value for R455A from the ASHRAE 34-2022. Three commenters also supported modified use
conditions for hydrocarbons, and specifically R-290, as outlined in UL 60335-2-89. They
noted that the standard allows self-contained equipment with more than 150 grams and
up to 500 grams of A2L and A3 flammable refrigerants.
Response: EPA did not open for comment the listings for air conditioning and
heat pump equipment in appendix R to 40 CFR part 82, subpart G mentioned by the
commenter. Rather, those entries were republished “to bring the table in line with the
Office of the Federal Register’s general requirement for orderly codification by: adding
entry numbers, replacing prohibited language, and properly formatting the footnotes” (87
FR at 45509; July 28, 2022). EPA considers the comment on the content of those existing
listings to be outside of the scope of this rulemaking.
In response to the comment regarding the incorrect LFL value from the standard’s
2ndd edition for R-455A, EPA agrees that this value could result in a reduction of
allowable charge sizes for R-455A. In this final rule and in EPA’s finalized risk screens,
EPA used 0.432 kg/m3as the LFL for R-455A, which is the value used in ASHRAE 342022.
In this final rule, EPA is modifying use conditions for R-290 to allow larger
charge sizes for retail food refrigeration—stand-alone units, self-contained retail food
refrigeration—refrigerated food processing and dispensing equipment, and self-contained
commercial ice machines, consistent with UL 60335-2-89. EPA acknowledges the

commenters’ support for these listings.
Comment: Three commenters requested that EPA draft the final rule so that the
latest industry standards are always incorporated by reference. The commenters stated
that doing so would increase alignment with safety standards while decreasing the need
for revisions by EPA. One commenter requested that EPA consider listing additional
refrigerants that were not in the proposal to enable the technology transitions proposed
under the AIM Act.
Response: Regarding the commenters request regarding an automatic process for
updating standards, EPA does not have a process to automatically incorporate future
standards into the rules, as the Agency must review each particular iteration of a standard
to understand it, determine whether it is appropriate for inclusion in the SNAP rules, and
identify whether there are any concerns and if so how to address those. Additionally,
EPA has often incorporated industry standards by reference, rather than drafting new
language, copying specific language from industry standards, or recommending rather
than requiring that industry follow standards. Updating the standard referenced in a
SNAP listing involves a change to regulations, and the Agency uses a notice-andcomment rulemaking process to change the standard that is incorporated into regulations.
EPA will continue to consider changes to relevant standards, and the Agency may
consider whether any revisions to the SNAP program regulations, including considering
approaches that do not rely on incorporating standards by reference, should be proposed
at a future date.
In response to comments related to listing additional refrigerants that were not in
the proposal to enable technology transitions in regulations under the AIM Act, EPA
notes that the requested additional listings are outside the scope of this rulemaking. EPA
intends to continue reviewing substitutes under the SNAP program, including refrigerants
that may provide more options to comply with regulations issued under the Technology

Transitions program, as suggested by the commenters, and consider whether listing of
such substitutes is appropriate under SNAP.
Comment: One commenter noted uncertainty related to ASHRAE 15 in that it
provides information on the use of A2L refrigerants in large remote systems but does not
specify where to place leak detection equipment; for example, whether leaked refrigerant
will dissipate or accumulate in particular locations. The commenter stated that the
engineer of record designing these applications would need to work through such
situations.
Response: EPA agrees that some situations may call for an engineer to decide on
the implementation of industry standards, particularly in cases where the standards do not
specify information on a particular topic. Uncertainty, however, related to ASHRAE 152022 specifications on leak detection is outside the scope of this rulemaking.
Comment: Eight commenters provided input on labeling, markings, and fittings
for flammable refrigerants. One commenter added that safety standards like UL 60335-240 and UL 60335-2-89 are developed through a consensus process with involvement
from a wide variety of stakeholders based on industry research, knowledge, and best
practices. One commenter mentioned that multiple standards recognize a class of less
flammable gases, such as category 1B flammable gases in the 7th edition of the Globally
Harmonized System of Classification and Labeling of Chemicals (GHS)—to which
OSHA recently harmonized its Hazard Communication Standard. This commenter also
stated that fire and building codes such as the International Code Council and the
National Fire Protection Association’s compressed gas code recognize the differences
between flammability classes 2L and 2 and 3 in ASHRAE 34 and category 1A and 1B
flammable gases in the GHS and suggested that EPA should prescribe use conditions
according to this distinction to be consistent with international practice, other Federal
agencies, industry standards and building codes. Two commenters stated that existing

industry standards related to packaging and warning labels are adequate to address safety
concerns associated with A2Ls.
Response: EPA agrees with the commenter that safety standards, like UL 603352-40 and UL 60335-2-89, were developed in an open and consensus-based approach,
with the assistance of experts in the AC industry as well as experts involved in assessing
the safety of products. However, given EPA’s stated concern for providing sufficient
warning to technicians, end users, the public, and first responders, and our understanding
that these groups are not sufficiently represented in the development of the standards,
EPA is finalizing use conditions and the Agency concludes that it is appropriate to
impose different marking and labeling requirements for A2L refrigerants from those in
UL 60335-3-89. The Agency considers these marking and labeling requirements to attract
attention and to provide more warning than the approach suggested by the commenters
for A2L refrigerants. In response to the comment about consistency with international
practice, other Federal agencies, industry standards and building codes that already
recognize distinctions between 2L and 2 or 3 flammability classifications, in this final
rule we are setting mitigation and charge requirements that recognize distinctions,
consistent with UL 60335-2-89 and ASHRAE 15. The additional requirement for red
markings and similar labeling requirements to standards with the same wording, but in
larger font for A2L refrigerants, will improve visibility of warnings. This approach is the
same as that in our previous rules on flammable refrigerants (e.g.,76 FR 78832,
December 20, 2011; 80 FR 19454, April 10, 2015; and 86 FR 24444, May 6, 2021).
Comment: Commenters provided comments on specific marking provisions
included in the proposed rule. Six commenters noted that EPA’s proposal does not align
with existing industry standards, namely UL 60335-2-89 and/or UL 60335-2-40, that do
not require red markings for mildly flammable refrigerants (i.e., A2Ls) but do require red
markings for A2 and A3 refrigerants that have higher flammability. They urged EPA to

align with existing standards. Five commenters requested that proposed red marking on
pipes, hoses, and other devices for A2L refrigerants be lessened or removed. Three
commenters noted that UL has removed this requirement for equipment with A2L
refrigerants. Two commenters stated that since A2L refrigerants are much less flammable
than A3 refrigerants, the use of red or colored service port caps would be sufficient for a
technician to distinguish between an A2L system and an A3 system (e.g., the flame
symbol applied to equipment near all ports for all flammable refrigerants will be an
indicator of flammability to technicians). They stated that the red Pantone® marking is
justified for A2 and A3 systems, given the significant flammability identified in testing.
Another commenter sought to clarify EPA’s proposal, stating that the way it currently
reads, it would mean that all piping would need to be red. Another commenter asserted
that SNAP should require the red tubing markings on all units containing flammable
refrigerants, inclusive of all A2L, A2, A3 and B2L units for safety reasons.
A different commenter questioned whether the proposal should be consistent
with the SNAP Rule 25 where Red Pantone® #185 was used to indicate the presence of a
flammable refrigerant.
Response: EPA is finalizing as proposed to require as a use condition that the
listed refrigerants must be used in refrigerating equipment that has red, PMS #185 or
RAL 3020 marked pipes, hoses, and other devices through which the refrigerant is
serviced, to indicate the use of a flammable refrigerant. EPA had the same requirement in
SNAP Rule 25.
Consistent with other rules promulgated under CAA section 612, EPA’s
requirements of red markings add an extra layer of safety on top of the labels required
under the UL standards, and EPA concludes this extra protection is appropriate for this
listing under SNAP. As previously noted, these types of red markings would signal to the
technician that the refrigerant circuit that she/he was about to access contained a

flammable refrigerant, even if all warning labels were somehow removed or were
illegible or not understood (e.g., for non-English speakers), and would provide similar
notification to consumers, retail store owners, building owners and operators, first
responders, and those disposing the appliance. We understand that UL 60335-2-89 treats
A2L and A3 refrigerants differently and that red markings are required by the UL
standard for A2 and A3 refrigerants, but not for A2L refrigerants. For this SNAP listing,
as in our past listings for A3 (and also A2L) refrigerants, EPA concluded that it is most
important to warn technicians that there is a flammable refrigerant present, not whether it
is specifically an A2L, A2, or A3 refrigerant. Once warned, we would expect the
technician to then seek to know which refrigerant is used and to proceed accordingly.
While we understand that the flammability risk can be considered ‘lower’ when using
A2L refrigerants compared to A3 refrigerants because of their higher LFL and higher
minimum ignition energy, a risk does exist compared to nonflammable refrigerants. The
red markings provide an additional warning to technicians, consumers, retail store
owners, building owners and operators, first responders, and those disposing the
appliance. We also note that the use of red markings is already required for past actions
for flammable refrigerants (76 FR 78832, December 20, 2011; and 80 FR 19454, April
10, 2015; and 86 FR 24444, May 6, 2021), and we are not aware that the marking
requirements have led to any confusion.
Concerning the comment that to meet the proposed use condition, all piping
would need to be red, EPA does not intend such a broad interpretation of the use
condition for red markings. The requirement is intended to mandate red markings of at
least one inch in each direction to go on locations such as a servicing port or processing
tube. For self-contained equipment that does not have a servicing port or processing tube,
a red marking, ring, or sleeve that extends at least one inch in each direction from a
location on tubing that is likely or recommended for servicing or recovering refrigerant is

sufficient.
EPA is finalizing that such markings apply to these A2L refrigerants as well, to
establish a common, familiar, and standard means of identifying the use of a flammable
refrigerant. After considering all the public comments on this proposal, we are finalizing
this use condition as proposed.
Comment: Five commenters mentioned the labeling requirements as they pertain
to SNAP Rules 23 and/or 25. Three commenters asked that EPA remove the labeling
requirements from this rule as well as earlier SNAP rules to eliminate inconsistencies
with existing standards. One commenter noted concerns around label size, stating that the
font must be legible, but not so large that the label cannot fit on the product. They noted
that small condensing units have limited space and meeting the existing requirements is a
challenge.
Response: EPA agrees with the commenter that the font must be legible and fit on
the product. EPA is finalizing that the labels must be provided in letters no less than 6.4
mm (1/4 inch) high, as proposed, as this is a reasonable size even for small condensing
units with limited space. The warning labels EPA is finalizing are similar to those
required as use conditions in SNAP Rule 23 and 25 (86 FR 24463, May 6, 2021). Labels
indicating flammability risk are critical to assuring proper identification and handling of
equipment containing potentially dangerous refrigerants. Using a common set of labels
aids in recognition and compliance, especially for a manufacturer that uses more than one
refrigerant. EPA also notes that comments requesting changes to requirements in other
SNAP rules such as SNAP Rule 23 or 25 fall outside the scope of this rulemaking.
Comment: A commenter stated that EPA’s proposal to add a new diamond
symbol would unduly burden manufacturers, asserting that the proposed new symbol fails
to serve any additional purpose given the presence of the red triangle.
Response: The Agency agrees with the comment that requiring the ISO 7000-

W021 flammability warning symbol in addition to the one that is presently required by
UL 60335-2-89 may place a burden on manufacturers. As explained by the commenter,
the existing edition of UL 60336-2-89, the 2nd edition, requires a red triangle while the 3rd
edition under development, which the Agency understands will require a GHS equalsided diamond with a red outline and a flame symbol on a white background for hazard
category 1 flammable gases, is not yet published. The Agency also understands after
consulting with fire service groups that the red triangle symbol in the present edition of
UL 2-89 may not be immediately recognized in the presence of a flammable refrigerant.
This is because a similar black symbol on a yellow triangle would refer first responder
fire servicers to a highly reactive oxidizer, rather than a flammable substance. This is
relevant because first responders would take different actions for an oxidizer from those
for a flammable substance.
Therefore, rather than requiring both symbols at this time, EPA is finalizing to
incorporate by reference UL 60335-2-89, with the exception that manufacturers may
choose which of the two proposed flammability symbols to use. Manufacturers may
choose to include either the red triangle warning symbol required in UL 60335-2-89, 2nd
edition, or manufacturers may choose to include the red diamond proposed. At least one
of these two symbols must be placed on refrigeration equipment covered by this rule that
uses flammable (e.g., A2L or A3) refrigerants. If manufacturers choose to include the red
triangle symbol instructed in the 2nd edition of UL 60335-2-89, then all requirements,
including those that refer to placement and size, must be followed accordingly. If
manufacturers choose to include the red diamond symbol proposed by EPA, all of the
following requirements, including those that refer to placement and size, must be
followed accordingly. EPA notes that if the diamond symbol is adopted in the 3rd edition
of UL 60335-2-89, manufacturers would be able to use it before the Agency would adopt
the 3rd edition, potentially reducing conflicts between EPA’s regulations and the UL

standard.
Comment: Three commenters requested that EPA increase the charge limits for R454A in the final rule. One of these commenters requested that EPA not limit the use of
R-454A to less than 200 pounds in the IPR, cold storage warehouse, and ice skating rink
sectors. The commenter stated that systems in these sectors require charge sizes larger
than 200 pounds and that R-454A is a more energy efficient and higher capacity
alternative with a GWP of less than 150. The commenter stated that charge limits for
systems in these sectors are not restricted by UL 60355-2-89 and that listing and
installation requirements of this standard would apply to few systems in industrial
occupancies. Another commenter stated that for R-454A applying a 200-pound charge
limit is not appropriate. Another of these commenters noted that the proposal stated that
the 200-pound limit for use of R-454A in remote condensing units and supermarkets is
inconsistent with ASHRAE 15 and UL 60335-2-89. The commenter stated that systems
following both of the standards could have charge sizes greater than 260 times the LFL,
or 200 pounds, if the releasable charges in an indoor space did not exceed either
standard’s limits. They requested that EPA harmonize with UL 60335-2-89 and
ASHRAE 15 on charge limits rather than imposing a charge limit distinct from the safety
standards. This commenter also provided comments on use conditions for R-454A. A
third commenter requested that EPA include language specifying the allowance of an
“unlimited charge” of R-454A in cold storage and the high-temperature side of cascade
systems.
Response: EPA acknowledges that the 200-pound limit for remote condensing
units and supermarkets may be inconsistent with ASHRAE 15 and UL 60335-2-89. EPA
recognizes that systems following either of these standards could have charge sizes up to
260 times the LFL, which under certain circumstances may exceed 200 pounds if the
releasable charge in an indoor space does not exceed either standard’s limit. However,

EPA disagrees that the 200-pound limit should be implemented through using the charge
limits that flow out of UL 60335-2-89 or ASHRAE 15. By requiring this charge limit as
its own use condition separate from the standards, EPA is highlighting that this charge
limit applies, even for use outdoors or in a machinery room. The Agency is requiring this
use condition specifically for R-454A so that users may select lower-GWP refrigerants
such as R-290, R-454C, R-455A, R-457A, R-516A, or R-744 with GWPs from one to
150, for use in locations that are not space constrained, such as in machinery rooms or
outdoors; the use condition still allows use of the higher-GWP and higher volumetric
capacity refrigerant R-454A in space-constrained locations. Also see responses
explaining EPA’s rationale for listing R-454A for supermarket systems and remote
condensing units with a use condition that refrigerant charge capacity be less than 200
pounds in sections II.A.6 and II.F.6 of this preamble.
EPA intends in this rule to differentiate between smaller systems that are used in
occupied spaces with public access, where the greater volumetric capacity of R-454A is
needed to fit into more constrained spaces, versus less constrained (or unconstrained)
spaces, such as outdoors or in machinery rooms. R-454A has a higher GWP than most of
the other refrigerants that EPA is listing in this rule–237 compared to 150 or less–and has
a greater volumetric capacity, as pointed out by the commenters. Thus, it is best used in
those situations where it may be more difficult to use other alternatives with even lower
GWPs because size constraints are greater–namely, where charge sizes would be less
than 200 pounds. In highly constrained spaces, however, refrigerants with lower
volumetric capacity and lower GWP may not technologically provide sufficient
performance, only allowing the use of a higher-GWP refrigerant, like R-454A. In
situations that are less space constrained and where only the ASHRAE 15 standard
governs, such as in machinery rooms or outdoors, other refrigerants with lower GWP and
lower volumetric capacity may be used and would reduce overall risk to human health

and the environment more than R-454A. Therefore, EPA disagrees with commenters’
requests to allow charge sizes greater than 200 pounds of R-454A in IPR and cold storage
warehouses. EPA elaborates that although the charge limits for some systems in these
sectors are not restricted by UL 60335-2-89 for industrial occupancies and could exceed
the 200-pound threshold, under the Technology Transitions Rule (88 FR 73098, October
24, 2023), refrigerants with a GWP between 150 and 300 can still be used in accordance
with the Technology Transitions Rule for charges less than 200 pounds in IPR,
supermarket systems, remote condensing units, and cold storage warehouses, as well as
for the high-temperature side of a cascade system. In light of this limitation and after
consideration of the commenters’ requests that EPA include language specifying the
allowance of an “unlimited charge” of R-454A in cold storage and the high-temperature
side of cascade systems, EPA is listing R-454A as proposed in those end-uses. EPA
clarifies that there is not a charge size limit on R-454A in the high-temperature side of a
cascade system for any of the end-uses in this final rule, except to the extent that such a
limit would be needed to be consistent with UL 60335-2-89 or ASHRAE 15.
For the ice skating rinks end-use, EPA notes that the Agency did not propose to
list R-454A as acceptable, either with or without a charge size limit. See section II.G.6 of
this preamble concerning comments on listing R-454A as acceptable in ice skating rinks.
I. Exemption for R-290 from the venting prohibition under CAA section 608 for
refrigerated food processing and dispensing equipment
1. What is EPA’s final determination regarding whether venting,
releasing, or disposing of R-290 in refrigerated food processing and dispensing
equipment would pose a threat to the environment?
Under section 608(c)(2) of the CAA, it is unlawful for any person, in the course
of maintaining, servicing, repairing, or disposing of an appliance or IPR, to knowingly
vent or otherwise knowingly release or dispose of any substitute substance for a class I or

class II substance used as a refrigerant in such appliance (or IPR) in a manner which
permits such substance to enter the environment. Under section 608(c)(2), this
prohibition applies to any substitute refrigerant unless the Administrator determines that
such venting, releasing, or disposing does not pose a threat to the environment. As
discussed in section II.B of this preamble, EPA is listing the refrigerant substitute R-290
under the SNAP program as acceptable, subject to use conditions, in newly manufactured
refrigerated food processing and dispensing equipment. EPA is also exempting R-290 in
this end-use from the venting prohibition under CAA section 608(c)(2), on the basis of
existing evidence that the venting, release, or disposal of this substance in this end-use
and subject to the use conditions in this final action does not pose a threat to the
environment. Further, as discussed in greater detail below, this exemption is consistent
with decisions in past rulemakings to exempt R-290 in other specific end-uses from the
venting prohibition under CAA section 608(c)(2), and it reflects EPA’s concern that there
is not yet sufficient recovery equipment suitable for use with highly flammable (A3)
refrigerants.
For purposes of CAA section 608(c)(2), EPA considers two factors in determining
whether or not venting, release, or disposal of a substitute refrigerant during the
maintenance, servicing, repairing, or disposing of appliances poses a threat to the
environment (69 FR 11948, March 12, 2004; 79 FR 29682, May 23, 2014; 80 FR 19453,
April 10, 2015; and 81 FR 86778, December 1, 2016). First, EPA analyzes the threat to
the environment due to inherent characteristics of the refrigerant substitute, such as GWP
or photochemical reactivity. Second, EPA determines whether and to what extent such
venting, release, or disposal actually takes place during the maintenance, servicing,
repairing, or disposing of appliances, and to what extent such actions are controlled by
other authorities, regulations, or practices. To the extent that such releases are adequately
controlled by other authorities, EPA defers to those authorities.

Potential environmental impacts
EPA has evaluated the potential environmental impacts of releasing into the
environment R-290, a substitute refrigerant that we are listing in this rule as acceptable,
subject to use conditions, in refrigerated food processing and dispensing equipment. We
assessed the potential impact of the release of R-290 on local air quality and its ability to
decompose in the atmosphere to form ground-level ozone, its ODP, its GWP, and its
potential impacts on ecosystems. We found that the magnitudes of these impacts were not
large enough to pose a threat to the environment. R-290’s ODP is zero, and its GWP is
approximately three. R-290 is highly volatile and typically evaporates or partitions to air,
rather than contaminating surface waters. Thus, R-290’s effects on aquatic life are
expected to be small.
As to potential effects on local air quality, R-290 meets the definition of VOC
under CAA regulations (40 CFR 51.100(s)) and is not excluded from that definition for
the purpose of developing SIPs to attain and maintain the NAAQS. R-290’s maximum
incremental reactivity (MIR) of 0.56 g O3/g R-290 is higher and more reactive than that
of ethane (MIR of 0.26 g O3/g ethane), which EPA uses as a threshold to determine
whether substances may have negligible photochemical reactivity in the lower
atmosphere (troposphere). EPA performed air quality modeling on a number of scenarios
to determine whether emissions of HC refrigerants could have a significant impact on
local air quality, particularly in certain cities with particularly difficult challenges in
achieving attainment of the NAAQS for ground-level ozone. The comparison of HC
refrigerant emissions was matched to the level of the NAAQS for the purposes of
illustrating that the even under a worst-case scenario the projected impacts on groundlevel ozone are small. Based on the analysis and modeling results described in section
II.B.3 of this preamble, EPA concludes that the release of R-290 from the refrigerated
food processing and dispensing end-use, in addition to the HCs previously exempted

from the venting prohibition and listed as acceptable, subject to use conditions, for their
specific end-uses, is expected to have little impact on local air quality. In this regard,
EPA found particularly noteworthy that even assuming 100 percent market penetration of
R-290 and the other acceptable HCs in the acceptable end-uses, which is a conservative
assumption, the highest impact for a single 8-hour average ozone concentration based on
that analysis would be 0.05 ppb in Los Angeles, 0.008 in Houston, and 0.005 in Atlanta
compared to the level of the 2015 ozone NAAQS at 70 ppb.81 The highest impact refers
to the greatest amount of ground-level ozone that could be created by the release of R290 and other HC refrigerants under the analysis’ most conservative scenarios.
In addition, EPA examined all HC substitute refrigerants in those uses for which
UL currently has standards in place for flammable refrigerants, for which the SNAP
program has already listed the uses as acceptable, subject to use conditions, and for which
the SNAP program is reviewing a submission, including the one in this action. We found
that even if all the HC refrigerant substitutes in appliances in end-uses listed acceptable,
subject to use conditions, in this action and listed as acceptable in previous rules were to
be emitted, as well as two hydrocarbon refrigerants that EPA ultimately listed as
unacceptable in certain end-uses, there would be a worst-case impact of less than 0.15
ppb for ground-level ozone in the Los Angeles area.82 The use conditions established in
the prior SNAP listings limited the total amount of R-290 in each refrigerant circuit to 60
g or less (for water coolers) or 150 g or less (for other end-uses), depending on the enduse. Changes in standards that are incorporated by reference as use conditions
(requirements) in the final SNAP listings in this rule would allow maximum charge sizes
of R-290 up to 494 g in retail food refrigeration-stand-alone units and retail food

ICF, 2016. Additional Follow-on Assessment of the Potential Impact of Hydrocarbon Refrigerants on
Ground Level Ozone Concentrations. September, 2016.
82 ICF, 2014a. Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground Level Ozone
Concentrations. February 2014.
refrigeration-refrigerated food processing and dispensing equipment, and self-contained
commercial ice machines. The analyses also assume R-290 and other, more reactive HC
refrigerants, may also be used in these end-uses, so our analysis assuming complete
market penetration of HCs is conservative.
EPA also has performed more recent air quality analysis before the publication of
this rule, considering additional end-uses and refrigerants that have been listed acceptable
more recently (e.g., R-1150 in very low temperature refrigeration), looking out to 2040,
and using updated models.83 EPA found that the revised air quality models showed
slightly greater impacts compared to our 2014 and 2016 analyses in all scenarios. For
example, in the worst-case scenarios where the most reactive HC refrigerant reviewed,
propylene, was used broadly across the refrigeration and AC industry, the worst-case
increase in ground-level ozone was 8.62 ppb in Los Angeles in the 2022 analysis
compared to 7.8 ppb in Los Angeles in an analysis in 2016 looking at the same scenario
with the same refrigerant. EPA made this comparison to see if that refrigerant, which the
SNAP program had previously listed as unacceptable in certain end-uses due to its
potential air quality impacts, would have similar, greater, or less impact using the updated
model for the same scenario compared to the earlier version of the model. Changes to the
Community Multiscale Air Quality (CMAQ) model, more updated refrigerant emissions
estimates from EPA’s Vintaging Model, as well as the longer time-period considered,
resulted in the changes. The 2016 analysis found that even assuming 100 percent market
penetration of R-290 and the other acceptable HCs in the end-uses where they are already
listed as acceptable, subject to use conditions, or were under review, which is a
conservative assumption, the highest impact for a single 8-hour average ozone
concentration based on the 2016 analysis would be 0.05 ppb in Los Angeles and less than

ICF, 2022. Additional Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground Level
Ozone Concentrations. May 2022. Updated models included VM IO file_v5.1_10.01.19 and CMAQ 5.2.1
with carbon bond 06 (CB06) mechanism, as cited in ICF, 2022.
0.01 ppb in Houston and Atlanta.84 Looking at the 2022 analysis, in the scenarios that
estimated emissions assuming that HC refrigerants listed as acceptable, subject to use
conditions, reached 100 percent market penetration, the worst-case increase in groundlevel ozone in Los Angeles was 0.012 ppb, in Houston was 0.009 ppb, and in Atlanta was
0.006 ppb. Unlike the 2014 and 2016 analyses, the 2022 analysis did not include
modeling of propylene or the propylene blend R-443A in certain end-uses, as those
refrigerants were listed as unacceptable in SNAP Rule 21 (81 FR 86778, December 1,
2016). For purposes of the analysis under CAA section 608(c)(2), the Agency considers
the modeled changes to ground-level ozone levels to be extremely small. For instance,
the modeled impacts on daily maximum 8 hour average ozone concentrations are less
than 0.017 percent of the level of the 2015 ozone NAAQS of 70 ppb.85 EPA considers the
2022 modeling to further support the Agency’s earlier conclusions in 2015 and 2016 that
use of saturated HCs as refrigerants, including release of R-290, R-600a, and R-441A
during repairing, maintaining, servicing, or disposing of appliances, would not result in a
significant increase in ground-level ozone, for purposes of determining whether to
exempt these refrigerants in specific end-uses from the venting prohibition under CAA
section 608(c)(2).
Considering our evaluation of these potential environmental impacts, EPA
concludes that R-290 in the refrigerated food processing and dispensing end-use is not
expected to pose a threat to the environment on the basis of the inherent characteristics of
this substance and the limited quantities used in the relevant end-use.
Authorities, controls, or practices
The determination of whether venting, release, or disposal of a substitute refrigerant
poses a threat to the environment includes considering whether such venting, release, or

ICF, 2016. Additional Follow-on Assessment of the Potential Impact of Hydrocarbon Refrigerants on
Ground Level Ozone Concentrations. September 2016.
85 ICF, 2020. Op cit.
disposal is adequately controlled by other authorities, regulations, or practices. EPA
expects that existing authorities, controls, and/or practices will mitigate environmental
risk from the release of R-290. Analyses performed for both this rule and the SNAP rules
issued in 1994, 2011, 2015, and 2016 (59 FR 13044, March 17, 1994; 76 FR 38832,
December 20, 2011; 80 FR 19453, April 10, 2015; and 81 FR 86778, December 1, 2016,
respectively) indicate that existing regulatory requirements and industry practices limit
and control the emission of R-290. For reasons discussed in proceeding paragraphs, EPA
concludes that the limits and controls under other authorities, regulations, or practices
adequately control the release of and exposure to R-290 and mitigate risks from any
possible release.
Industry service practices and OSHA standards and guidelines that address HC
refrigeration equipment include monitoring efforts, engineering controls, and operating
procedures. OSHA requirements that apply during servicing include continuous
monitoring of explosive gas concentrations and oxygen levels. In general, HC emissions
from refrigeration systems are likely to be significantly smaller than those emanating
from the industrial process and storage systems, which are controlled for safety reasons.
In Sections II.B.7, “What updates to existing use conditions for stand-alone units is EPA
finalizing?” and II.D.5, “What updates to existing use conditions for commercial ice
machines is EPA finalizing?” we note that the amount of R-290 from a refrigerant loop is
effectively limited to roughly 500 g or 300 g in the end-uses listed in this rule. This
indicates that HC emissions from such uses are likely to be relatively small.
As discussed in Section II.B.3, “What is R-290 and how does it compare to other
refrigerants in the refrigerated food processing and dispensing equipment end-use
category?”, EPA’s SNAP program evaluated the flammability and toxicity risks from R290 in the new end-use in this final rule. EPA is providing some of that information in

this section as well, to provide information on the potential for leaks and exposure due to
R-290.
R-290 is classified as an A3 refrigerant by ASHRAE 34-2022 and subsequent
addenda, indicating that it has low toxicity and high flammability. R-290 has an LFL of
2.1 percent. To address flammability risks, this document provides recommendations and
use conditions for its safe use (see Section II.H.2, “What additional information is EPA
including in these listings?”). The SNAP program’s analysis finds that the use conditions
in this rule will mitigate flammability risks.
Like most refrigerants, at high concentrations HCs can displace oxygen and cause
asphyxiation. Various industry and regulatory standards exist to address asphyxiation and
toxicity risks. The SNAP program’s analysis of asphyxiation and toxicity risks suggests
that the use conditions in this final rule will mitigate asphyxiation and toxicity risks.
Furthermore, it is the Agency’s understanding that flammability risks and occupational
exposures to HCs are adequately regulated by OSHA and building and fire codes at a
local and national level.
The release and/or disposal of many refrigerant substitutes, including R-290, are
controlled by other authorities including various standards and State and local building
codes. The industry consensus safety standard UL 60335-2-89, which EPA is
incorporating by reference in use conditions in the SNAP listing for R-290 in refrigerated
food processing and dispensing equipment, is one of these standards, and industry also
applies the standard ASHRAE 15. Code-making organizations, such as the International
Code Council (ICC), are in the process of updating references to the most recent industry
standards that address use of R-290 and other flammable refrigerants in the International
Building Code (IBC). The specific editions of UL 60335-2-89 and ASHRAE 15 that are
incorporated in this rulemaking as use conditions are in the process of being adopted in
the next version of the IBC; once the IBC adopts those standards, State and localities may

adopt those revisions into their State or local building codes. To the extent that release
during maintaining, repairing, servicing, or disposing of appliances is controlled by
regulations and standards of other authorities, these practices and controls for the use of
R-290 are sufficiently protective. These practices and controls mitigate the risk to the
environment that may be posed by the venting, release, or disposal of R-290 during the
maintaining, servicing, repairing, or disposing of appliances.
EPA is aware of equipment that can be used to recover HC refrigerants. While
there are no relevant U.S. standards for such recovery equipment currently, to the extent
that R-290 is recovered rather than vented in specific end-uses and equipment, EPA
recommends the use of recovery equipment designed specifically for flammable
refrigerants in accordance with applicable safe handling practices.
2. What is EPA’s final determination regarding whether venting of R-290
from refrigerated food processing and dispensing equipment is exempted from the
venting prohibition under CAA section 608(c)(2)?
Consistent with the listing under SNAP in this action, EPA determines that
venting, releasing, or disposing of R-290 in refrigerated food processing and dispensing
equipment is not expected to pose a threat to the environment during the maintaining,
servicing, repairing, or disposing of appliances. As discussed in section II.A.1 of this
preamble, EPA is making this determination on the basis of the inherent characteristics of
this substance, the limited quantities used in the relevant end-use, and the limits and
controls under other authorities, regulations, or practices that adequately control the
release of and exposure to R-290 and mitigate risks from any possible release.
Accordingly, EPA is revising the regulations at 40 CFR 82.154(a)(1) to add R-290 in this
end-use to the list of substitute refrigerants that are exempt from the venting prohibition
under CAA section 608(c)(2).
3. When will the exemption from the venting prohibition apply?

This exemption for R-290 in refrigerated food processing and dispensing
equipment applies 30 days after the publication of this final rule in the Federal Register,
on and after [INSERT DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE
FEDERAL REGISTER]. This is the same as the effective date of the SNAP listing of R290 in refrigerated food processing and dispensing equipment.
4. What is the relationship between this exemption under CAA section
608(c)(2) and other EPA rules?
This final exemption from the CAA section 608(c)(2) venting prohibition does
not mean that R-290 used in refrigerated food processing and dispensing equipment can
be vented in all situations. R-290 released or otherwise disposed of from commercial and
industrial appliances is likely to be hazardous waste under RCRA (see 40 CFR parts 260
through 270). As discussed in the final rules addressing the venting of ethane (R-170), R600a, R-290, and R-441A as refrigerant substitutes in certain end-uses, incidental releases
may occur during the maintenance, service, and repair of appliances subject to CAA
section 608 (79 FR 29682, May 23, 2014; 80 FR 19454, April 10, 2015; 81 FR 86778,
December 1, 2016). Such incidental releases would not be subject to RCRA requirements
for the disposal of hazardous waste, as such releases would not constitute disposal of the
refrigerant charge as a solid waste, per se. For commercial appliances such as refrigerated
food processing and dispensing equipment, it is likely that R-290 and other flammable
HC refrigerant substitutes would be classified as hazardous waste, and recycling,
reclamation or disposal of R-290 from such appliances would need to be managed as
hazardous waste under the RCRA regulations (40 CFR parts 260 through 270), unless it
is subject to a limited exception in those regulations if the ignitable refrigerant is to be
reused without first being processed to remove contamination.
5. How is EPA responding to comments on the exemption for R-290 from
the venting prohibition?

Comment: Four commenters suggested that R-290 should not be exempt from the
CAA section 608 venting prohibition. Three of these commenters were in favor of
applying section 608 to all refrigerants, including hydrocarbons. One of these
commenters supported a prohibition on venting due to R-290’s flammability hazards.
Another commenter noted the flammability concern when larger charge sizes are
involved. A different commenter further specified that R-290’s flammability and safety
concerns could be magnified with charge sizes of 494g allowed by UL 60335-2-89 and
potentially other U.S. standards based on proposed updates (e.g., ASHRAE 15.2). One
commenter noted flammability concerns related to system designs for hydrocarbon
refrigerants. They specified that in these systems, venting does not typically remove all
the refrigerant and the residual hydrocarbon refrigerant can create flammability concerns
if the system is brazed or welded.
Response: For the reasons discussed in Section II.I of this preamble,
“Exemption for R-290 from the venting prohibition under CAA section 608 for
refrigerated food processing and dispensing equipment,” EPA disagrees with the
commenters and finds that venting, release, or disposal of R-290 in the retail food
refrigeration—refrigerated food processing and dispensing end-use and subject to the use
conditions listed in this action does not pose a threat to the environment. EPA’s decision
is based on consideration of multiple environmental characteristics. The comments do not
provide sufficient analysis to support a reason for EPA to change our proposed
conclusion that the venting permitted by this exemption of these refrigerant substitutes in
these end-uses, subject to the required use conditions, do not pose a threat to the
environment, or to change this final rule so that they would not be exempt from the
venting prohibition. EPA evaluated risk associated with scenarios with charge sizes larger
than 494 g in stand-alone units and refrigerated food processing and dispensing
equipment and concluded that R-290 is acceptable for these specific end-uses with use

conditions according to industry standards. For example, flammability risks can be
addressed for stand-alone units and refrigerated food processing and dispensing
equipment by installing the equipment in a space with appropriate capacity and charge
size for the intended area, and following manufacturer guidelines and safety standards
(ASHRAE 15, ASHRAE 34, UL 60335-3-89). EPA also notes that its evaluation of
substitutes is based on the information currently available; proposed updates that are not
yet released did not factor into the listings of this rule. As discussed in the use conditions
for R-290, venting is allowed during the maintenance, servicing, repair, or disposal of
specific appliances, like stand-alone and refrigerated food processing and dispensing
equipment. Regarding the commenter’s concern that venting does not typically remove
all the refrigerant from these systems, EPA responds that proper handling and
flammability warning labels as described in section II.H of this preamble serve a
preventative role by notifying trained personnel handling equipment about the presence
of a flammable refrigerant, even in the unlikely event that there would be a sufficient
residue of R-290 left after venting to create a flammability risk. EPA has also made the
same finding for R-290 in the past, as well as for other alkane refrigerants (e.g., R-600a,
R-441A). EPA recognizes that there are flammability risks both during venting and
during use of recovery equipment with A3 refrigerants; until the refrigeration and airconditioning industry has further development and market penetration of recovery
equipment with non-sparking components, the flammability risks of potentially using
inappropriate recovery equipment with R-290 may be greater than the flammability risk
of controlled releases of R-290 outdoors.
In addition, EPA’s exemption from the CAA venting prohibition of these
substances in these end-uses is consistent with how other countries, including Australia,
Japan, and those in the European Union, regulate the venting of hydrocarbons.

Comment: Four commenters drew comparisons between R-290 and other
refrigerants or classes of refrigerants. Three of these commenters expressed concern that
allowing the venting of one type of flammable refrigerant may cause confusion in the
industry as the use of low-GWP refrigerants becomes widespread. One commenter noted
that if EPA’s rationale for exempting R-290 is its low GWP, then HFOs should likewise
be exempt. This commenter also stated that unlike R-290, HFOs are not VOC and do not
contribute to ground-level ozone. A different commenter raised a climate impact concern
due to the reactivity of R-290 to form ground-level ozone, which is also a greenhouse
gas, and thus R-290 should not be exempted from refrigerant recovery requirements. A
different commenter noted that if hydrocarbons become more widely used, volumes of
hydrocarbons vented could increase; while hydrocarbons generally have low GWPs, the
GWP values do not take into account the total emissions from the supply chain.
Response: In response to comments about confusion over venting only one type
of flammable refrigerant, EPA notes that technicians should already be aware of these
differences for other types of self-contained equipment using R-290, R-600a, or R-441A,
and this would not change substantially for refrigerated food processing and dispensing
equipment, which is less common than those other types of self-contained equipment.
Further, it is EPA’s understanding that it is relatively uncommon for self-contained
equipment to be serviced, compared to equipment with remote compressors, so removing
R-290 from equipment would typically occur at disposal of the equipment.
Concerning the comment suggesting that EPA should also exempt HFOs, EPA
did not propose and is not finalizing an exemption for HFOs from the CAA prohibition to
knowingly vent or otherwise knowingly release refrigerants. EPA disagrees with the
comment that R-290’s low GWP is the sole reason EPA is exempting R-290 from the
venting prohibition. EPA has discussed in this section the multiple factors that it
considers, and the fact that HFOs are subject to the venting prohibition is irrelevant to the

R-290 analysis. Further, if EPA were to evaluate exempting one or more HFOs in a
particular end-use from the venting prohibition, that analysis would appropriately focus
on the inherent characteristics and other authorities, practices and controls that are
relevant to HFOs in that end-use, not on the analysis for R-290, which differs from HFOs
in some respects, such as with respect to flammability risks and availability of
appropriate recovery equipment. In response to the comment that there is a climate
impact from formation of ground-level ozone, EPA acknowledges that ground-level
ozone is a greenhouse gas; however, given the small additional amounts of ground-level
ozone that EPA has calculated would be generated, even in the worst case, the additional
climate impact is negligible. Concerning the comment regarding indirect climate impacts
from emissions along the supply chain, EPA acknowledges that there are also other
climate impacts in addition to direct GWP of emissions of a substitute. However, there
would also be the same indirect climate impacts from emissions along the supply chain,
whether EPA exempts R-290 in refrigerated food processing and dispensing equipment
from the CAA 608(c)(2) venting prohibition or not. The Agency has addressed the
possibility of greater use of HC refrigerants by conservatively assuming complete market
penetration (i.e., being the only refrigerants used) in all end-uses where there has been
interest in the use of hydrocarbons to date. Thus, after considering public comments
received, EPA’s conclusions concerning exempting R-290 in refrigerated food processing
and dispensing equipment remain the same and EPA is finalizing as proposed.
Comment: A couple of commenters noted concerns related to the status of R-290
as a VOC. One commenter stated that HC refrigerants are VOC and can impact local air
quality particularly in densely populated areas that are likely to have the most air
conditioning and refrigeration equipment. Another commenter expressed concern for the
apparent inconsistency presented by the proposed exemption of R-290 from the CAA
section 608(c)(2) venting prohibition versus other EPA regulations where R-290 is not

considered VOC-exempt (i.e., is not excluded from the definition of VOC for the purpose
of developing SIPs to attain and maintain the NAAQS). This commenter stated that R290 has a MIR value more than twice the MIR of ethane, which EPA has used as a
reference point for determining whether to allow a substance to obtain an VOC
exemption. This commenter stated that the EPA should use the same approach to
determine whether propane should be exempt from the CAA section 608(c)(2) venting
prohibition as whether it should be VOC-exempt. The commenter stated that using a
“worst-case impact approach” is inconsistent with previous approaches that determined
VOC exemptions based on information showing that 1) VOC are of low photochemical
reactivity and they can be ignored in oxidant control programs, or that 2) compounds
more reactive than ethane continue to be considered VOC for regulatory purposes.
Response: In response to these comments, EPA notes that the second commenter
fails to recognize the distinctions between two different regulatory provisions. To the
extent the comments relate to whether propane should be excluded from the definition of
VOC (see 40 CFR 51.100(s)) for the purpose of addressing the development of SIPs to
attain and maintain the NAAQS, they are beyond the scope of this rulemaking and
require no further response. EPA did not reopen and is not making any changes to 40
CFR 51.100(s) in this action.
EPA’s regulations under 40 CFR part 82, subpart F prohibit individuals from
knowingly venting or otherwise releasing into the environment ozone-depleting
substances or their substitutes used as a refrigerant while maintaining, servicing,
repairing, or disposing of appliances or industrial process refrigeration. See 40 CFR
82.154. Consistent with section 608(c)(2) of the CAA, EPA has established regulatory
exemptions from this prohibition for certain refrigerants used in specific end-uses where
EPA has determined that the release does not pose a threat to the environment. The
Agency considers multiple factors on a refrigerant-by-refrigerant basis before deciding to

establish such an exemption from the venting prohibition under 40 CFR 82.154. EPA has
previously established exemptions from the venting prohibition for propane in particular
end-uses. See 40 CFR 82.154(a)(1)(viii) (exemption for R-290 in retail food refrigerators
and freezers (stand-alone units only); household refrigerators, freezers, and combination
refrigerators and freezers; self-contained room air conditioners for residential and light
commercial air-conditioning and heat pumps; vending machines; and self-contained
commercial ice machines, very low temperature refrigeration equipment, and water
coolers). Among other things, in establishing these exemptions EPA has described the
analysis supporting its determination that venting, releasing, or disposing of propane in
the particular end-uses at issue does not pose a threat to the environment, and it has
explained that the controlled release of propane outdoors may be the safest option in
certain circumstances as many recovery machines are not equipped to properly recover
highly flammable refrigerants (e.g., recovery machines without spark proof
components).86 EPA is taking a similar approach here and its conclusions are consistent
with those prior EPA actions. The potential environmental impact of releases of propane
and other HC refrigerants in multiple analyses, as described above in section II.I.1 of this
preamble. We considered the inherent characteristics of these substitute refrigerants and
the limited quantities used in the relevant applications. Those analyses show that use of
saturated HCs as refrigerants, including release of R-290, R-600a, and R-441A during
repairing, maintaining, servicing, or disposing of appliances, would not result in a
significant increase in ground-level ozone. Based on this review, EPA concludes that the
venting, releasing, or disposing of propane in these end-uses and subject to these use
conditions are not expected to pose a threat to the environment.
Regarding both commenters’ concerns with propane’s status as a VOC and the

86 81 FR 86778 at 86801

first commenter’s concerns regarding the potential for local air quality impacts, the
Agency clarifies that even if a substance is defined as a VOC under 40 CFR 51.100(s), it
can still be exempted from the venting prohibition under CAA section 608 and 40 CFR
82.154, if the appropriate determination under CAA section 608(c)(2) is made. While
EPA may consider a substance’s status as a VOC under CAA regulations (40 CFR
51.100(s)) addressing the development of SIPs to attain and maintain the NAAQS in
making that determination, that may not be the sole or determinative factor in making a
determination under section 608(c)(2), as other factors may also affect whether such
venting poses a threat to the environment. EPA’s prior decisions to provide a limited
exemption to the venting prohibition for R-290, and other refrigerants that are VOC
under the Agency’s regulatory definition under CAA regulations (40 CFR 51.100(s))
addressing the development of SIPs to attain and maintain the NAAQS, in particular end
uses are examples of this result. In those situations, EPA also evaluated potential local air
quality impacts using conservative assumptions and has provided a limited exemption
from the venting prohibition for these substitutes in these end-uses under section
608(c)(2) of the CAA because the Agency concluded that it was appropriate to make the
statutory determination that supports the exemption from the venting prohibition. EPA is
taking a similar approach here, as described above in section II.I.1 of this preamble, and
is reaching the same conclusion.
Comment: One commenter expressed concern that EPA has arbitrarily set a “de
minimis” part per billion level (i.e., 0.15 ppb resulting from the Assessment of the
Potential Impact of Hydrocarbon Refrigerants on Ground Level Ozone Concentrations
(ICF, 2014) for purposes of evaluating the ozone impacts of this rule. The commenter
also notes that there is no such impact threshold applied by EPA when considering
whether State Implementation Plans (SIPs) adequately address sources within a State that
may contribute to nonattainment or interference with maintenance of the NAAQS

implying that EPA should not use an ozone impact threshold for the purposes of
evaluating the impacts of this rule.
Response: EPA disagrees with the commenter that the incremental value from the
2014 analysis of 0.15 ppb was applied as an arbitrary “de minimis” threshold for
evaluating local ozone impacts. EPA used the 2014 analysis containing the 0.15 ppb
value in previous SNAP rulemakings listing HC refrigerants, as well as for this
rulemaking, to illustrate that even the worst-case impact from HC refrigerants, including
R-290, would be small. These analyses were considered as part of the overall evaluation
of risks to human health and the environment that supported certain listing decisions in
this rule, as discussed above. More recent analyses were performed prior to this rule’s
development and came to similar conclusions that potential local air quality impacts of
emissions of saturated hydrocarbons used as refrigerants would be small; these analyses
are in the docket for this rulemaking. For the SNAP program, as part of the analysis
under 40 CFR 82.180(a)(7), the Agency considers whether there will be increased overall
risk to the population due to ambient exposure to increased ground-level ozone as a result
of using the alternative refrigerants in the final rule, among several other criteria. The
commenter appears to conflate the requirements for evaluating air quality impacts and
general population risk due to exposure to increased ground-level ozone for the purpose
of SNAP with the requirements for developing State Implementation Plans to implement
the NAAQS. The two are unrelated. This rule has no effect on development of State
Implementation Plans or other aspects of NAAQS implementation, and to the extent
comments are related to those subjects, they are beyond the scope of this rulemaking and
require no further response. Finally, as described in this preamble, the more recent air
quality modeling performed in 2022 demonstrated that the largest worst-case increase in
ground-level ozone due to use of acceptable HC refrigerants was 0.012 ppb, which is
even lower than the worst-case value, 0.15 ppb, from previous analysis in 2014. For

purposes of a benchmark for comparison, the level of the 2015 NAAQS, which is
currently in effect, is 70 ppb (as the fourth-highest daily maximum 8-hour concentration,
averaged across three consecutive years), more than four orders of magnitude higher.
Comment: One commenter suggested that EPA align its RCRA regulations to
allow for the venting of R-290 and the other flammable refrigerants as allowed under 40
CFR 82.154(a). The commenter noted that most of the refrigerated food processing and
dispensing end-use appliances will not be in household locations; therefore, these
appliances will not fall under the RCRA household exemption, and the refrigerant cannot
be vented due to RCRA regulations. The commenter added that R-290 from the
refrigerated food processing and dispensing end-use will be required to be managed as
hazardous waste (characteristic of ignitability) (e.g., recovered and managed as RCRA
hazardous waste as opposed to venting).
Response: EPA did not propose to revise regulations issued under RCRA in this
rulemaking, and thus the request to revise those rules is outside the scope of this
rulemaking.
J. How is EPA responding to other comments?
Comment: Nine commenters broadly supported Proposed Rule 26. One
commenter added that choice of alternatives is an important factor regarding assuring
economic success of the ozone protection program, and they are generally supportive of
proposed decisions that offer flexibility of choice and improve overall environmental
performance. Another commenter indicated that they support EPA’s application of the
new refrigerants to cold storage warehouses, ice skating rinks, and industrial processes. A
different commenter supported the Agency's efforts to further enable lower-GWP
solutions in the end-uses regulated under the SNAP program but proposed that standard
clarifications, listing of additional substitutes, use condition modifications, and R-290
venting prohibitions should be included in the final SNAP Rule 26 to advance the safe

and orderly transition to lower-GWP solutions. These commenters’ detailed comments
appear under the appropriate section headings within this document.
Response: EPA acknowledges the commenters’ support of the listings in this
rulemaking. EPA is finalizing many listing decisions as proposed and is finalizing other
listing decisions with relatively minor changes that address and incorporate information
provided in comments as described throughout the preamble. EPA acknowledges the
commenter’s concern for the GWPs of various refrigerants and for the commenter’s
recognition that new alternatives will be more widely adopted in the future. EPA plans to
continue to review substitutes consistent with the SNAP program criteria, including
atmospheric impacts such as GWP impacts. EPA addresses comments about standard
clarifications and use conditions in section II.H.2 of this preamble and R-290 exemptions
in section II.I.5 of this preamble.
Comment: One commenter noted support for listing HFO-1234yf. The commenter
stated that industry has made significant investments in research and development, and
expanded capacity for production of HFO refrigerants, which are used as refrigerants or
components in refrigerant blends.
Response: EPA acknowledges the commenter’s support for listing HFO-1234yf in
this rulemaking. EPA is finalizing acceptable listings for HFO-1234yf as proposed.
Comment: A different commenter provided detailed comments cautioning against
listing HFO-1234yf due to environmental and public health concerns. This commenter
stated that HFO-1234yf stands apart from the other substitutes because of a higher
toxicity concern. They mentioned a by-product of breakdown called trifluoroacetic acid
(TFA)–a substance they described as a per- and polyfluoroalkyl substance (PFAS). They
stated that these short-chain PFAS are widely detected, persistent, and mobile in aquatic
systems. The commenter noted that the TFA yield for HFO-1234yf (1.0) is higher than
that of HFC-134a (0.2). They asserted negative impacts of TFA include toxicity to plants,

harm to aquatic organisms, and potential harm to human and ecosystem health. The
commenter urged EPA not to list HFO-1234yf as there are other safer alternatives
available for cold storage, IPR, commercial ice machines, food retail, chillers, ice skating
rink and other end-uses, including low global warming potential hydrocarbons, carbon
dioxide, and ammonia.
Response: EPA appreciates the information provided by a commenter on the
atmospheric decomposition of HFO-1234yf to TFA. We note that several studies and
reports provide further information about this topic. A 2014 study by Kazil, et al.
analyzed TFA deposition in the United States assuming 100 percent of all motor vehicle
air conditioning systems use HFO-1234yf, which was the largest use of HFO-1234yf at
that time.87 The results indicated that rainwater TFA concentrations, while varying
strongly geographically, would on average be low compared to the levels at which toxic
effects are observed in aquatic systems. Similarly, low TFA concentrations were
estimated for emissions of HFO-1234yf from Asia in a 2021 study by David, et al.88 The
World Meteorological Organization (WMO) also provided a summary of key information
pertaining to TFA in their 2022 report to the Montreal Protocol.89 The report states:
The formation in the atmosphere of trifluoroacetic acid (TFA) is expected to
increase in the coming decades due to increased use of HFOs and HCFOs. TFA, a
breakdown product of some HFCs, HCFCs, HFOs and HCFOs, is a persistent
chemical with potential harmful effects on animals, plants, and humans. The
concentration of TFA in rainwater and ocean water is, in general, significantly
below known toxicity limits at present. Potential environmental impacts of TFA
require future evaluation due to its persistence. (p. 14)

Kazil et al., 2014. “Deposition and rainwater concentrations of trifluoroacetic acid in the United States
from the use of HFO-1234yf” J. Kazil, S. McKeen, S.-W. Kim, R. Ahmadov, G.A. Grell, R.K. Talukdar,
A.R. Ravishankara. JGR Atmospheres. Volume 119, Issue 24. December 27, 2014. Pages 14,059–14,079.
October 31, 2014. Available online at https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/
2014JD022058.
88 David et al., 2021. “Trifluoroacetic acid deposition from emissions of HFO-1234yf in India, China, and
the Middle East,” Volume 21, issue 19. Atmos. Chem. Phys., 21, 14833–14849, 2021. https://doi.org/
10.5194/acp-21-14833-2021. Available online at https://acp.copernicus.org/articles/21/14833/2021.
89 WMO, 2022. Executive Summary. Scientific Assessment of Ozone Depletion: 2022, GAW Report No.
278, 56 pp.; WMO: Geneva, 2022. Available online at https://ozone.unep.org/system/files/documents/
Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf.
Most TFA currently found in the environment resulting from decomposition of
refrigerants likely derived from HFC-134a, which is being phased down and the use of
which is anticipated to decrease in end-uses where safer alternatives are found acceptable
under the SNAP program. EPA also notes that the modeling studies referenced generally
assume a one-to-one substitution of HFO-1234yf for HFC-134a to be conservative. Any
increase in TFA deposition due to this rule is expected to be less than the modeled
increases in TFA from studies that found the levels of TFA in the environment remained,
“too small to be a risk to the environment over the next few decades.” Use of HFO1234yf and concerns about TFA in applications not addressed by this final rule are
outside the scope of this rulemaking.
There are ongoing evaluations of the potential risks of TFA exposure. In 2020, the
Environmental Effects Assessment Panel (EEAP) to the Montreal Protocol released an
update 90 to its report on the environmental effects of stratospheric ozone depletion, UV
radiation, and interactions with climate change, including the potential effects of TFA
from ODS and their substitutes. That report noted that TFA “has a no-observed-effectconcentration (NOEC) for aquatic species, which is typically >10,000 μg/L,” while
“analysis of 1187 samples of rainwater collected in eight locations across Germany in
2018–2019 showed median and a precipitation-weighted mean concentration of TFA of
0.210 μg/L and 0.335 μg/L, respectively,” and “another recent paper reported TFA . . . in
precipitation in the low μg/L range across 28 cities in mainland China.” These studies and
others led the EEAP to state, “Trifluoroacetic acid continues to be found in the
environment, including in remote regions, although not at concentrations likely to have
adverse toxicological consequences.”

EEAP, 2020. “Environmental effects of stratospheric ozone depletion, UV radiation, and interactions
with climate change: UNEP Environmental Effects Assessment Panel, Update 2020.” Photochemical &
Photobiological Sciences https://doi.org/10.1007/s43630-020-00001-x. Available online at:
https://engineering.case.edu/centers/sdle/sites/engineering.case.edu.centers.sdle/files/neale_et_al._-_2021environmental_effects_of_stratospheric_ozone_deple.pdf.
In its 2021 Summary Update for Policymakers,91 the EEAP stated:
TFA likely has natural geochemical sources, is widely used in
industry and research laboratories, and is a by-product of the synthesis and
degradation of fluorinated and perfluorinated compounds (PFCs). . . . TFA
has recently been found in precipitation, surface waters, and indoor dust in
China . . ., although concentrations are below those considered toxic. No
additional studies on the toxicity of TFA to organisms have been reported,
but prior research has shown that this compound is not highly toxic to
mammals and aquatic organisms, although some plants and algae may be
sensitive….At present, it is not possible to quantify the proportion of
anthropogenic sources of TFA resulting from substances not falling under
the purview of the Montreal Protocol, but available evidence indicates that
this breakdown product is of minimal risk to human health. (p. 10;
references in the text omitted here)
Most recently, in its 2022 Assessment Report,92 the EEAP stated:
TFA has a long environmental lifetime, accumulates in surface and ground
waters, and has been found in blood, drinking water, beverages, dust, plants, and
agricultural soils. However, it does not interact with biological molecules and, due
to its high solubility in water, it does not bioaccumulate. It is unlikely to cause
adverse effects in terrestrial and aquatic organisms. Continued monitoring and
assessment are nevertheless advised due to uncertainties in the deposition of TFA
and its potential effects on marine organisms (p.5)
The Montreal Protocol has led to the replacement of ODSs with fluorinated
chemicals, some of which can undergo degradation in the atmosphere to give
TFA in various yields. TFA is known to have a long environmental lifetime and
accumulates in surface and ground waters. At present, there are large uncertainties
associated with the concentrations of TFA in various environmental
compartments in some regions, as well as the relative proportion of anthropogenic
sources related to the Montreal Protocol, compared to the other anthropogenic and
natural sources. There is some uncertainty in toxicity values because of the
limited number of marine species tested. Current and predicted concentrations (to
year 2100) of TFA in the oceans provide a large margin of exposure (thousandfold) when compared to thresholds of toxicity. (p. 294)
EPA considers ecotoxicity as a criterion when evaluating alternatives under
SNAP’s comparative risk framework, and the Agency has considered the potential
impacts of TFA for the listings in this rule and in past actions that found HFO-1234yf

EEAP, 2021. “Summary Update 2021 for Policymakers” UNEP Environmental Effects Assessment
Panel. Available online at https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summaryupdate-2021-for-policymakers.pdf .
92 EEAP, 2023. 2022 Assessment Report of Stratospheric Ozone Depletion, UV Radiation, and
Interactions with Climate Change. UNEP, Environmental Effects Assessment Panel. May, 2023.Available
online at: https://ozone.unep.org/system/files/documents/EEAP-2022-Assessment-Report-May2023.pdf
acceptable in certain end-uses. For example, EPA studied the potential generation of TFA
when first listing neat (i.e., 100 percent, not in blends) HFO-1234yf as acceptable, subject
to use conditions, in motor vehicle air conditioning. The myriad studies EPA referenced
all concluded that the additional TFA from HFO-1234yf did not pose a significant
additional risk, even if it were assumed to be used as the only refrigerant in all
refrigeration and air conditioning equipment (76 FR 17492–17493, March 29, 2011). The
Agency intends to continue its approach to evaluating the potential risks from TFA in
future SNAP regulations.
With regard to the commenter’s stance that safer low-GWP substitutes than HFO1234yf currently exist for these end-uses, EPA disagrees. A number of alternatives can
meet low-GWP and safety goals and EPA evaluates these potential alternatives through a
holistic risk screen analysis with overall impact to human health and the environment in
mind. The SNAP program’s aim is to expand the list of available substitutes that
successfully meet conservative risk screen analysis thresholds so that industry may pull
from a number of substances that can be used in equipment and that suit their
functionality and needs. Risk screens, which can be viewed under this rule’s docket, were
performed for industrial process refrigeration, cold storage warehouses, ice skating rinks,
commercial ice machines, and retail food refrigeration. The findings of these risk screens
conclude that HFO-1234yf does not pose a safety risk if used according to the safety
standards required in this rule’s use conditions, such as UL 60335-2-89. HFO-1234yf has
a GWP less than one, is excluded from the regulatory definition of VOC for the purpose
of addressing the development of SIPs to attain and maintain the NAAQS and can be
used without exceeding health-based exposure limits in the end-uses where it is being
listed. Therefore, EPA does not consider the overall risk to human health and the
environment due to HFO-1234yf in this final rule to be greater than for other available or
potentially available substitutes for the same uses.

Comment: One commenter noted support for listing HFO-1234ze. The commenter
stated that industry has made significant investments in research and development and
has expanded capacity for production of HFOs, which are used as refrigerants or
components in refrigerant blends.
Response: EPA acknowledges the commenter’s support for listing HFO-1234ze
in this rulemaking. EPA has finalized acceptable listings for HFO-1234ze(E) as
proposed.
Comment: One commenter requested that EPA clarify whether the mention of R424A on page 33731 of the Proposed Rule should have read R-454A.
Response: EPA agrees and clarifies that the mention of R-424A should have
instead read R-454A. We have updated this language in this preamble.
Comment: Two commenters expressed support for listing R-455A. They urged
swift action by EPA to approve this substitute. One commenter added that R-455A will
provide industry with additional options to assist in their transition away from higherGWP products and will help users achieve a GWP limit of 150 for certain commercial
refrigeration applications.
Response: EPA acknowledges the commenters’ support for listing R-455A in this
rulemaking. EPA is finalizing acceptable listing decisions for R-455A as proposed,
including certain commercial refrigeration applications.
Comment: Seven commenters noted related aspects of the current rulemaking to
rulemakings under the AIM Act. Three of these commenters explicitly mentioned this
SNAP rulemaking as an opportunity to adopt lower-GWP refrigerants in line with the
objectives of the Technology Transitions Rule. The three commenters supported EPA
listing such additional low-GWP refrigerants.
One commenter noted that they particularly support certain charge size limits in
some of the approvals, which will help EPA meet its goals under the proposed

Technology Transition rule.
One commenter encouraged EPA to approve refrigerants on a priority basis for
end-uses capable of complying with the HFC restrictions in the Technology Transitions
Rule. The commenter stated that this will bring about a practical phase down of HFCs in
these applications that are critical to health and human comfort.
Response: EPA plans to continue to review substitutes consistent with the SNAP
program criteria, including atmospheric impacts such as climate impacts. EPA agrees
with commenters that the alternatives addressed in this SNAP rulemaking will provide
additional lower-GWP options to comply with the HFC restrictions in the Technology
Transition regulations.
Comment: One commenter noted concerns related to a January 1, 2025, deadline
under EPA's regulations implementing the AIM Act for transitioning to new lower-GWP
refrigerants. This commenter stated that it is not possible to change hundreds of designs,
test, and acquire UL approvals in that time period. The commenter mentioned that if
suppliers cannot provide the equipment needed for this transition it would have
detrimental business consequences. The commenter added that it is difficult to find
qualified engineers to develop these projects; failure to extend deadlines could potentially
cause many small refrigeration companies to go out of business.
Response: Comments related to EPA’s regulations under the AIM Act are outside
the scope of this rulemaking.
Comment: A commenter opposed the use of R-454A (GWP 239) or any other
refrigerant with a GWP greater than 150 in self-contained equipment that exceeds the 150
GWP limit proposed under the Technology Transitions Rule.
Response: To the extent that this comment relates to the Technology Transitions
Rule, EPA notes that it is outside the scope of this rulemaking. To the extent the
commenter is referring to self-contained commercial ice machines, see the response in

Section II.C.6 of the preamble. If the commenter is referring to other self-contained
equipment in addition to self-contained commercial ice machines, EPA notes that we did
not propose to list, and are not listing, any refrigerants with a GWP greater than 150 in
retail food refrigeration—stand-alone units or retail food refrigeration—refrigerated food
processing and dispensing equipment.
Comment: Three commenters referenced refrigerants or end-uses that were not
part of the proposal. Two commenters referenced standards and requirements related to
residential and light commercial air conditioning and heat pumps. One of these
commenters suggested that rather than designating a specific numerical charge limit for
R-290 in the sector, the final rule should refer more generally to the maximum charge
size as allowed in UL 484 or UL 60335-2-40, which would provide a mechanism for
automatic adjustment in response to new information. Another commenter suggested
harmonization of U.S. industry safety standards under UL 60335-2-40 and the ASHRAE
15 standard with the most recent edition of the IEC 60335-2-40 standard. This
commenter stated that aligning to the IEC standard would accelerate the transition away
from climate polluting substances in many air conditioning and heat-pump systems, such
as R-410A (GWP >2,000), to sustainable alternatives, such as R-290 (GWP three). This
commenter felt that adopting the IEC standard would usher in uptake of low-GWP
refrigerants in the air conditioning and heat pump sectors, as evidenced by the swift
transition to R-600a (GWP three) in the refrigerator market following a 2017 update to
the UL standard. One commenter asked EPA to consider listing substitutes that are not
part of the proposal. They asked for EPA to consider listing HCFO-1233zd(E) and R471A for use in commercial refrigeration generally to assist in the transition away from
higher-GWP refrigerants.
Response: EPA acknowledges these comments expressing support for
hydrocarbons and other lower-GWP refrigerants in AC equipment. EPA did not propose

listings for refrigerants in AC, and therefore, these comments are outside the scope of this
final rule. The Agency may consider proposing additional listings, including listings for
lower-GWP refrigerants in residential and light commercial air conditioning and heat
pumps, in future rulemakings and may also consider updating use conditions for existing
hydrocarbon listings. The Agency also did not propose to list R-471A and HCFO1233zd(E) for use in other end-uses; therefore, these comments are beyond the scope of
this rulemaking. Every substitute listed under the SNAP program undergoes a
comparative risk analysis for submitted end-uses; the substitutes suggested by
commenters did not undergo risk screen review. To list the greatest number of low-GWP
refrigerant options for industry to use as is possible, the commenters’ suggested
substitutes and end-uses will not be included within the scope of this rulemaking. EPA
also notes that in other listing documents, we have listed both R-471A and HCFO1233zd(E) as acceptable in some end-uses, e.g., listing of R-471A as acceptable in new
equipment for retail food refrigeration, IPR, and cold storage warehouses (88 FR 61977,
September 8, 2023).
Comment: One commenter noted that EPA identifies hydrocarbons and R-717 as
secondary refrigerants and asserted that these would not be used as secondary fluids.
Response: EPA agrees with the commenter that hydrocarbons and R-717 would
not typically be used as a secondary fluid that is pumped throughout a store to cases in a
cascade system. Rather, hydrocarbons and R-717 could be used as the primary refrigerant
used to cool a secondary fluid in a cascade system or secondary loop system. In the final
rule, EPA is revising the statement to read, “Examples of secondary fluids include water,
brine, propylene glycol, air, and carbon dioxide (CO2).”
III. Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders can be found at
https://www.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 14094:
Modernizing Regulatory Review
This action is not a significant regulatory action as defined in Executive Order
12866, as amended by Executive Order 14094 and was therefore not submitted to the
Office of Management and Budget (OMB) for review.
B. Paperwork Reduction Act (PRA)
This action does not impose any new information collection burden under the
PRA. OMB has previously approved the information collection activities contained in the
existing regulations and has assigned OMB control number 2060-0226. The approved
Information Collection Request includes five types of respondent reporting and
recordkeeping activities pursuant to SNAP regulations: submission of a SNAP petition,
filing a Toxic Substances Control Act (TSCA)/SNAP Addendum, notification for test
marketing activity, recordkeeping for substitutes acceptable, subject to use restrictions,
and recordkeeping for small volume uses. This rule contains no new requirements for
reporting or recordkeeping.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic impact on a
substantial number of small entities under the RFA. In making this determination, EPA
concludes that the impact of concern for this rule is any significant adverse economic
impact on small entities and that the agency is certifying that this rule will not have a
significant economic impact on a substantial number of small entities because the rule
has no net burden on the small entities subject to the rule. This action lists additional
options under SNAP for using HFC-32, HFO-1234yf, HFO-1234ze(E), R-290, R-454A,
R-454B, R-454C, R-455A, R-457A, and R-516A in the specified end-uses, but does not
mandate such use. Because equipment for HFO-1234yf, HFO-1234ze(E), R-454A, R454B, R-454C, R-455A, R-457A, and R-516A is not manufactured yet in the U.S. for

retail food refrigeration equipment, commercial ice machines, IPR, cold storage
warehouses, and ice skating rinks, no change in business practice is required to meet the
use conditions, resulting in no adverse impact compared with the absence of this rule.
The new use conditions for R-290 in stand-alone units and self-contained commercial ice
machines were requested by industry and are consistent with the most recent, updated
industry standard. These allow for greater consistency in business practices for different
types of equipment using the same refrigerant, as well as provide greater flexibility in
designing and manufacturing equipment. Equipment for R-290 already manufactured
prior to the effective date of this rule will not be required to be changed. Stand-alone
units and self-contained commercial ice machines using R-290 have been subject to
similar use conditions, and thus the updated requirements result in no adverse impact
compared with the absence of this rule. Thus, the rule does not impose new costs on
small entities. We have therefore concluded that this action will have no net regulatory
burden for all directly regulated small entities.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain any unfunded mandate of $100 million (adjusted
annually for inflation) or more (in 1995 dollars) as described in UMRA, 2 U.S.C. 1531–
1538, and does not significantly or uniquely affect small governments. The action
imposes no enforceable duty on any State, local, or Tribal governments or the private
sector.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have substantial
direct effects on the States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the various levels of
government.
F. Executive Order 13175: Consultation and Coordination with Indian Tribal

Governments.
This action does not have Tribal implications as specified in Executive Order
13175. It will not have substantial direct effects on Tribal governments, on the
relationship between the Federal Government and Indian Tribes, or on the distribution of
power and responsibilities between the Federal Government and Indian Tribes, as
specified in Executive Order 13175. Thus, Executive Order 13175 does not apply to this
action. EPA periodically updates Tribal officials on air regulations through the monthly
meetings of the National Tribal Air Association and will share information on this
rulemaking through this and other fora.
G. Executive Order 13045: Protection of Children from Environmental Health and Safety
Risks
Executive Order 13045 (62 FR 19885, April 23, 1997) directs Federal agencies to
include an evaluation of the health and safety effects of the planned regulation on
children in Federal health and safety standards and explain why the regulation is
preferable to potentially effective and reasonably feasible alternatives. This action is not
subject to Executive Order 13045 because it is not a significant regulatory action under
section 3(f)(1) of Executive Order 12866, and because the EPA does not believe the
environmental health or safety risks addressed by this action present a disproportionate
risk to children. While EPA has not conducted a separate analysis of risks to infants and
children associated with this rule, the rule contains use conditions that reduce exposure
risks to the general population, with the reduction of exposure being most important to
the most sensitive individuals. This action’s health and risk assessments are contained in
the comparisons of toxicity for the various substitutes, as well as in the risk screens for
the substitutes that are listed in this rule. The risk screens are in the docket for this
rulemaking. However, EPA’s Policy on Children’s Health applies to this action.
H. Executive Order 13211: Actions that Significantly Affect Energy Supply, Distribution,

or Use
This action is not subject to Executive Order 13211, because it is not a significant
regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act and Incorporation by Reference
This action involves technical standards. EPA has decided to use and incorporates
by reference UL 60335-2-89, which establishes requirements for the evaluation of
commercial refrigeration equipment and commercial ice machines and safe use of
flammable refrigerants, among other things. This standard is discussed in greater detail in
section II.H.1 of this preamble.
UL 60335-2-89, “Standard for Safety for Household And Similar Electrical
Appliances - Safety - Part 2-89: Particular Requirements for Commercial Refrigerating
Appliances and Ice-Makers with an Incorporated or Remote Refrigerant Unit or Motor
Compressor,” 2nd edition, October 27, 2021, is available at:
https://www.shopulstandards.com/ProductDetail.aspx?productId=UL60335-289_2_S_20211027, and may be purchased by mail at: COMM 2000, 151 Eastern
Avenue, Bensenville, IL 60106; email: orders@shopulstandards.com; Telephone: 1-888853-3503 in the U.S. or Canada (other countries dial 1-415-352-2178); Internet address:
https://ulstandards.ul.com or https://www.shopulstandards.com. The cost of the 2021
standard UL 60335-2-89 is $519 for an electronic copy and $649 for a hard copy. UL
also offers a subscription service to the Standards Certification Customer Library that
allows unlimited access to their standards and related documents. The cost of obtaining
this standard is not a significant financial burden for equipment manufacturers and
purchase is not necessary for those selling, installing, and servicing the equipment.
Therefore, EPA concludes that the UL standard being incorporated by reference is
reasonably available.
EPA is also incorporating by reference Chapter 2.2, Flammable Gasses, and

Annex 1, Classification and Labelling Summary Tables, of ST/SG/AC.10/30/Rev.9,
Global Harmonized System (GHS) of Classification and Labelling of Chemicals, Ninth
revised edition, copyright 2021, which define the GHS diamond symbol (pictogram) for
hazard category 1 flammable gasses, in the use conditions for hazard labeling of
commercial and industrial refrigeration equipment. Printed versions and electronic
editable versions are available for sale at the United Nations Publications section
at: https://shop.un.org/books/global-harmon-syst-class-9-92280 and may be purchased by
mail at: United Nations Publications Customer Service, P.O. Box 960, Herndon, VA
20172; by email at order@un.org; and by telephone at 1-703-661-1571. The cost of the
9th edition of the GHS is $75.00 for an electronic copy or $150.00 for a printed hard copy.
A copyright permission request is not required for the use of up to 2 graphs, charges,
tables, and figures. The cost of obtaining this standard is not a significant financial
burden for equipment manufacturers or for those selling, installing, and servicing the
equipment. Therefore, EPA concludes that the material incorporated by reference is
reasonably available.
EPA is also incorporating by reference ANSI/ASHRAE Standard 15-2022, Safety
Standard for Refrigeration Systems, copyright 2022, in the use conditions for refrigerants
listed for use in larger refrigeration equipment (see summary in Section II.A.4 of the
preamble) and ANSI/ASHRAE Standard 34-2022, Designation and Safety Classification
of Refrigerants, copyright 2022, in the use conditions for labeling refrigeration equipment
with the safety classification of the refrigerant used (see summary in Section II.A.2 of the
preamble). These standards are available at https://www.ashrae.org/technicalresources/bookstore/ashrae-refrigeration-resources and may be purchased by mail at: 180
Technology Parkway NW, Peachtree Corners, Georgia 30092; by telephone: 1-800-5274723 in the U.S. or Canada. ASHRAE 15-2022 and ASHRAE 34-2022 are available as a
bundle costing $169.00 for an electronic copy or hard copy. The cost of obtaining the

standard is not a significant financial burden for equipment manufacturers or for those
selling, installing, and servicing the equipment. Therefore, EPA concludes that the
ASHRAE standards incorporated by reference are reasonably available.
EPA is also incorporating by reference ANSI/ASHRAE Addendum a to
ANSI/ASHRAE Standard 34-2022, Designation and Safety Classification of
Refrigerants, ANSI-/ASHRAE-approved December 20, 2022. This standard is available
at https://www.ashrae.org/technical-resources/standards-and-guidelines/standardsaddenda. Addenda for ASHRAE standards are available online in PDF format for free.
Addendum a adds burning velocity data, updates some LFL values, and corrects several
calculation errors that were identified, particularly for RCL values driven by flammability
versus toxicity.
The following standards are already approved for incorporation by reference at
the locations where they appear in the amendatory text: UL 471, UL 541, UL 484, UL
60335-2-24, and UL 60335-2-40.
J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority
Populations and Low-Income Populations and Executive Order 14096: Revitalizing Our
Nation’s Commitment to Environmental Justice for All
The EPA believes that the human health or environmental conditions that exist
prior to this action result in or have the potential to result in disproportionate and adverse
human health or environmental effects on communities with environmental justice
concerns. EPA’s analysis indicates that other environmental impacts and human health
impacts of listing HFC-32, HFO-1234yf, HFO-1234ze(E), R-290, R-454A, R-454B, R454C, R-455A, R-457A, and R-516A in the end-uses addressed in this action are
comparable to or less than those of other substitutes that are listed as acceptable for the
same end-use. For example, these alternative refrigerants would likely have lower climate

impacts because of their lower GWPs compared to other available substitutes for the
same uses.
The EPA believes that it is not practicable to assess whether this action is likely to
result in new disproportionate and adverse effects on communities with environmental
justice concerns. Because adoption of the new substitutes listed in this rule is voluntary,
the Agency is unable to quantify when, where, and how much of the listed substitutes
will be produced and used. Thus, EPA cannot determine the extent to which this rule will
exacerbate or reduce existing disproportionate adverse effects on communities of color
and low-income people as specified in Executive Order 12898 (59 FR 7629, February 16,
1994).
However, the listings for HFC-32, HFO-1234yf, HFO-1234ze(E), R-290, R454A, R-454B, R-454C, R-455A, R-457A, and R-516A in the end-uses addressed in this
action provide additional lower-GWP or comparable alternatives in their respective enduses. By providing lower-GWP or comparable alternatives for these end-uses, this rule is
anticipated to reduce the use and eventual emissions of potent greenhouse gases in these
end-uses, which could help to reduce the effects of climate change, including the existing
disproportionate public health and welfare effects on communities with environmental
justice concerns. The Agency will continue to evaluate the impacts of this program on
communities with environmental justice concerns and consider further action, as
appropriate.
The EPA additionally identified and addressed environmental justice concerns by
conducting and sharing risk screens and air quality modeling to provide information to
the public about the listed refrigerants contained in this rulemaking. The information
supporting this Executive Order review is contained in the comparison of health and
environmental risks for HFC-32, HFO-1234yf, HFO-1234ze(E), R-290, R-454A, R454B, R-454C, R-455A, R-457A, and R-516A as well as in the risk screens that are

available in the docket for this rulemaking.
K. Congressional Review Act (CRA)
This action is subject to the CRA, and the EPA will submit a rule report to each
House of the Congress and to the Comptroller General of the United States. This action is
not a “major rule” as defined by 5 U.S.C. 804(2).

IV. References
Unless specified otherwise, all documents are available electronically at
regulations.gov, docket number EPA-HQ-OAR-2023-0043.
ASHRAE, 2022a. ANSI/ASHRAE Standard 15-2022: Safety Standard for Refrigeration
Systems. 2022.
ASHRAE, 2022b. ANSI/ASHRAE Standard 34-2022: Designation and Safety
Classification of Refrigerants. 2022.
ASHRAE, 2022c. Addendum a to ANSI/ASHRAE Standard 34–2022, Designation and
Safety Classification of Refrigerants: ANSI—approved December 30, 2022.
Carter, 2010. “Development of the SAPRC-07 Chemical Mechanism and Updated Ozone
Reactivity Scales,” Report to the California Air Resources Board by William P. L.
Carter. Revised January 27, 2010.
EEAP, 2021. “Summary Update 2021 for Policymakers” UNEP Environmental Effects
Assessment Panel. Available online at: https://ozone.unep.org/sites/default/files/
assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.
EEAP, 2023. 2022 Assessment Report of Stratospheric Ozone Depletion, UV Radiation,
and Interactions with Climate Change. UNEP, Environmental Effects Assessment
Panel. May, 2023. Available online at:
https://ozone.unep.org/system/files/documents/EEAP-2022-Assessment-ReportMay2023.pdf.

GHS, 2021. Pictogram for Hazard Category 1 Flammable Gases from Annex 1 to the 9th
edition of the Global Harmonized System of Classification and Labelling of
Chemicals, 2021. Available online from the United Nations Publications section
at: https://shop.un.org/books/global-harmon-syst-class-9-92280.
Hodnebrog, et al., 2013. Hodnebrog, Ø., Etminan, M., Fuglestvedt, J.S., Marston, G.,
Myhre, G., Nielsen, C.J., Shine, K.P., and Wallington, T.J. (2013). Global
Warming Potentials and Radiative Efficiencies of Halocarbons and Related
Compounds: A Comprehensive Review, Reviews of Geophysics, 51, 300–378.
Available at: doi.org/10.1002/rog.20013.
ICF, 2014. Assessment of the Potential Impact of Hydrocarbon Refrigerants on Ground
Level Ozone Concentrations. February, 2014.
ICF, 2016. Additional Follow-on Assessment of the Potential Impact of Hydrocarbon
Refrigerants on Ground Level Ozone Concentrations. September, 2016.
ICF, 2022. Additional Assessment of the Potential Impact of Hydrocarbon Refrigerants
on Ground Level Ozone Concentrations. May, 2022.
ICF, 2024a. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: HFO-1234yf.
ICF, 2024b. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: HFO-1234ze(E) (Solstice® ze, Solstice® 1234ze).
ICF, 2024c. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: R-454A (Opteon® XL40).
ICF, 2024d. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: R-454C (Opteonâ„¢ XL20).
ICF, 2024e. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: R-455A (Solstice® L40X).
ICF, 2024f. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);

Substitute: R-457A (Forane® 457A).
ICF, 2024g. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: R-516A (Forane® 516A).
ICF, 2024h. Risk Screen on Substitutes in Retail Food Refrigeration (New Equipment);
Substitute: Propane (R-290).
ICF, 2024i. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: HFC-32.
ICF, 2024j. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: HFO-1234yf.
ICF, 2024k. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-454A (Opteon® XL40).
ICF, 2024l. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-454B (Opteon® XL41).
ICF, 2024m. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-454C (Opteonâ„¢ XL20).
ICF, 2024n. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-455A (Solstice® L40X).
ICF, 2024o. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-457A (Forane® 457A).
ICF, 2024p. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: R-516A (Forane® 516A).
ICF, 2024q. Risk Screen on Substitutes in Commercial Ice Machines (New Equipment);
Substitute: Propane (R-290).
ICF, 2024r. Risk Screen on Substitutes in Industrial Process Refrigeration (New
Equipment); Substitute: HFC-32 (Difluoromethane).

ICF, 2024s. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: HFO-1234yf.
ICF, 2024t. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: HFO1234ze(E) (Solstice® ze, Solstice® 1234ze).
ICF, 2024u. Risk Screen on Substitutes in Industrial Process Refrigeration and Cold
Storage Warehouses (New Equipment); Substitute: R-454A (Opteon® XL40).
ICF, 2024v. Risk Screen on Substitutes in Industrial Process Refrigeration (New
Equipment); Substitute: R-454B (Opteon® XL41).
ICF, 2024w. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: R-454C
(Opteonâ„¢ XL20).
ICF, 2024x. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: R-455A
(Solstice® L40X).
ICF, 2024y. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: R-457A
(Forane® 457A).
ICF, 2024z. Risk Screen on Substitutes in Industrial Process Refrigeration, Cold Storage
Warehouses, and Ice Skating Rinks (New Equipment); Substitute: R-516A
(Forane® 516A).
IPCC, 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working
Group I to the Fourth Assessment Report of the Intergovernmental Panel on
Climate Change. Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M.,
Averyt, K.B., Tignor, M., and Miller, H.L. (eds.). Cambridge University Press.
Cambridge, United Kingdom and New York, NY, USA. Available at:

https://www.ipcc.ch/report/ar4/wg1.
Nielsen et al., 2007. Nielsen, O.J., Javadi, M.S., Sulbaek Andersen, M.P., Hurley, M.D.,
Wallington, T.J., Singh, R. (2007). Atmospheric chemistry of CF3CF=CH2:
Kinetics and mechanisms of gas-phase reactions with Cl atoms, OH radicals, and
O3. Chemical Physics Letters 439, 18–22. Available at:
www.lexissecuritiesmosaic.com/gateway/FedReg/network_OJN_174_CF3CF=C
H2.pdf.
UL 471, 2010. Commercial Refrigerators and Freezers. 10th edition. Supplement SB:
Requirements for Refrigerators and Freezers Employing a Flammable Refrigerant
in the Refrigerating System. November 24, 2010.
UL 563, 2009. Standard for Safety: Ice Makers—Supplement SA: Requirements for Ice
Makers Employing a Flammable Refrigerant in the Refrigerating System, 8th
edition, July 31, 2009, including revisions through November 29, 2013.
UL 60335-2-89, 2021. Household And Similar Electrical Appliances - Safety - Part 2-89:
Particular Requirements for Commercial Refrigerating Appliances and IceMakers with an Incorporated or Remote Refrigerant Unit or Motor Compressor.
2nd edition. October 27, 2021.
U.S. EPA, 2020. 2017 National Emissions Inventory Report. U.S. Environmental
Protection Agency. Available online at https://gispub.epa.gov/neireport/2017/.
World Meteorological Organization, 2022. Burkholder et al. Appendix A, Table A-5 in
Scientific Assessment of Ozone Depletion: 2022, GAW Report No. 278, 509 pp.;
WMO, Geneva, Switzerland, https://ozone.unep.org/science/assessment/sap.
(WMO, 2022).

List of Subjects in 40 CFR Part 82
Environmental protection, Administrative practice and procedure, Air pollution
control, Incorporation by reference, Stratospheric ozone layer.

Michael S. Regan,
Administrator.

For the reasons stated in the preamble, EPA amends 40 CFR part 82 as follows:
PART 82—PROTECTION OF STRATOSPHERIC OZONE
1. The authority citation for part 82 continues to read as follows:
Authority: 42 U.S.C. 7414, 7601, 7671-7671q.
Subpart F—Recycling and Emissions Reduction
25. 5.

2. Amend §82.154 by revising paragraph (a)(1)(viii) to read as follows:

§ 82.154 Prohibitions.
(a) * * *
(1) * * *
(viii) Propane (R-290) in retail food refrigerators and freezers—stand-alone units;
household refrigerators, freezers, and combination refrigerators and freezers; selfcontained room air conditioners for residential and light commercial air-conditioning and
heat pumps; vending machines; self-contained commercial ice machines, very low
temperature refrigeration equipment, and water coolers; and effective [INSERT DATE
30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER],
retail food refrigeration—refrigerated food processing and dispensing equipment;
*

*

*

*

*

Subpart G–Significant New Alternatives Policy Program
3. Amend appendix R to subpart G of part 82 by:
a. Revising the heading; and
b. Revising the table titled “Substitutes That Are Acceptable Subject to Use
Conditions.”
The revisions read as follows:
Appendix R to Subpart G of Part 82—Substitutes Subject to Use Restrictions Listed
in the December 20, 2011, Final Rule, Effective February 21, 2012, in the April 10,
2015, Final Rule, Effective May 11, 2015, in the April 28, 2023, Final Rule, Effective
May 30, 2023, and in the [INSERT DATE OF PUBLICATION IN THE FEDERAL
REGISTER], Final Rule, Effective [INSERT DATE 30 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER]

Substitutes That Are Acceptable Subject to Use Conditions
End-use
1. Household
refrigerators,
freezers, and
combination
refrigerators
and freezers
(New
equipment
only)

Substitute
Isobutane
(R-600a),
Propane
(R-290),
R-441A

Decision
Acceptable
subject to
use
conditions

Use Conditions
As of September 7, 2018: These
refrigerants may be used only in
new equipment designed
specifically and clearly identified
for the refrigerant (i.e., none of
these substitutes may be used as a
conversion or “retrofit” refrigerant
for existing equipment designed for
a different refrigerant).
These refrigerants may be used
only in a refrigerator or freezer, or
combination refrigerator and
freezer, that meets requirements
listed in UL 60335-2-24.1,2,6

Further Information
Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation),
1910.106 (flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), 1910.157
(portable fire extinguishers),
and 1910.1000 (toxic and
hazardous substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage
of equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as
per 29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment
rise above one-fourth of the
lower flammability limit, the
space should be evacuated
and re-entry should occur
only after the space has been
properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal
protective equipment,
including chemical goggles
and protective gloves, when
handling these refrigerants.
Special care should be taken
to avoid contact with the skin
since these refrigerants, like
many refrigerants, can cause
freeze burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on refrigerators and
freezers with these
refrigerants.
Any recovery equipment
used should be designed for
flammable refrigerants. Any
refrigerant releases should be
in a well-ventilated area, such
as outside of a building.
Only technicians specifically
trained in handling flammable

2. Retail Food
Refrigeration
—stand-alone
units only
(New
equipment
only)
manufactured
on or after
February 21,
2012, and up
to but not
including
[INSERT
DATE 30
DAYS
AFTER
DATE OF
PUBLICATI
ON IN THE
FEDERAL
REGISTER]

Isobutane
(R-600a)
Propane
(R-290)
R-441A

Acceptable
subject to
use
conditions

These refrigerants may be used
only in new equipment specifically
designed and clearly identified for
the refrigerants (i.e., none of these
substitutes may be used as a
conversion or “retrofit” refrigerant
for existing equipment designed for
other refrigerants).
These substitutes may only be
used in equipment that meets
requirements in Supplement SB to
UL 471.1,2,3 In cases where this
listing 2 includes requirements
more stringent than those of UL
471, the appliance must meet the
requirements of this listing 2 in
place of the requirements in the UL
Standard.
The charge size for the retail food
refrigerator or freezer shall not
exceed 150 grams (5.3 ounces) in
each circuit.
As provided in clauses SB6.1.2 to
SB6.1.5 of UL 471,1,2,3 the
following markings shall be
attached at the locations provided
and shall be permanent:
(a) On or near any evaporators
that can be contacted by the
consumer: “DANGER-Risk of Fire
or Explosion. Flammable
Refrigerant Used. Do Not Use
Mechanical Devices To Defrost
Refrigerator. Do Not Puncture
Refrigerant Tubing.”
(b) Near the machine
compartment: “DANGER-Risk of
Fire or Explosion. Flammable
Refrigerant Used. To Be Repaired
Only By Trained Service
Personnel. Do Not Puncture
Refrigerant Tubing.”
(c) Near the machine
compartment: “CAUTION—Risk
of Fire or Explosion. Flammable
Refrigerant Used. Consult Repair
Manual/Owner’s Guide Before
Attempting To Service This
Product. All Safety Precautions
Must be Followed.”
(d) On the exterior of the
refrigerator: “CAUTION—Risk of
Fire or Explosion. Dispose of
Properly In Accordance With

refrigerants should service
refrigerators and freezers
containing these refrigerants.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely.
Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids), 1910.110
(storage and handling of
liquefied petroleum gases),
1910.157 (portable fire
extinguishers), and 1910.1000
(toxic and hazardous
substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage of
equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as per
29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment rise
above one-fourth of the lower
flammability limit, the space
should be evacuated and
reentry should occur only after
the space has been properly
ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal protective
equipment, including chemical
goggles and protective gloves,
when handling propane.
Special care should be taken to
avoid contact with the skin
since propane, like many
refrigerants, can cause freeze
burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on refrigerators and
freezers with propane.
Recovery equipment
designed for flammable
refrigerants should be used.
Only technicians
specifically trained in handling
flammable refrigerants should
service refrigerators and

3. Retail Food
Refrigeration
—stand-alone
units only
(New
equipment
only)
manufactured
from
[INSERT
DATE 30
DAYS
AFTER
DATE OF
PUBLICATI
ON IN THE
FEDERAL
REGISTER],
through
September
29, 2024, or
equipment
manufactured
on or after
September
30, 2024,
except for
equipment
manufactured
on or after
September
30, 2024, that

Isobutane
(R-600a)
Propane
(R-290)
R-441A

Acceptable
subject to
use
conditions

Federal Or Local Regulations.
Flammable Refrigerant Used.”
(e) Near any and all exposed
refrigerant tubing: “CAUTION—
Risk of Fire or Explosion Due To
Puncture Of Refrigerant Tubing;
Follow Handling Instructions
Carefully. Flammable Refrigerant
Used.”
All of these markings shall be in
letters no less than 6.4 mm (1⁄4
inch) high.
The refrigerator or freezer must
have red, Pantone® Matching
System #185 or RAL 3020 marked
pipes, hoses, and other devices
through which the refrigerant is
serviced, typically known as the
service port, to indicate the use of a
flammable refrigerant. This color
must be present at all service ports
and where service puncturing or
otherwise creating an opening from
the refrigerant circuit to the
atmosphere might be expected
(e.g., process tubes). The color
mark must extend at least 2.5
centimeters (1 inch) from the
compressor and must be replaced if
removed.
These substitutes may only be
used in equipment that meets
requirements of either:
1. Supplement SB to UL 4711,2,3
and listing 2 of this table or
2. ASHRAE 15-2022,1,9,12 UL
60335-2-89,1,2,8 and listing 4 of this
table.

freezers containing this
refrigerant. Technicians should
gain an understanding of
minimizing the risk of fire and
the steps to use flammable
refrigerants safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.
If a service port is added
then stand-alone retail food
refrigeration units using these
refrigerants should have
service aperture fittings that
differ from fittings used in
equipment or containers using
non-flammable refrigerant.
“Differ” means that either the
diameter differs by at least
1/16 inch or the thread
direction is reversed (i.e.,
right-handed vs. left-handed).
These different fittings should
be permanently affixed to the
unit at the point of service and
maintained until the end-oflife of the unit, and should not
be accessed with an adaptor.

remains
unchanged,
other than
cosmetic
changes, from
an earlier
model or
design that
was already
certified to
the UL
4711,2,3
standard
before
September
30, 2024
4. Retail Food
Refrigeration
—stand-alone
units only
(New
equipment
only)
manufactured
on or after
September
30, 2024,
except for
equipment
manufactured
on or after
September
30, 2024, that
remains
unchanged,
other than
cosmetic
changes, from
an earlier
model or
design that
was already
certified to
the UL
4711,2,3
standard
before
September
30, 2024

Isobutane
(R-600a)
Propane
(R-290)
R-441A

Acceptable
subject to
use
conditions

This refrigerant may be used only
in new equipment specifically
designed and clearly identified for
the refrigerant (i.e., this substitute
may not be used as a conversion or
“retrofit” refrigerant for existing
equipment designed for other
refrigerants).
This refrigerant may be used in
new stand-alone units if and only if
such equipment meets all
requirements listed in ASHRAE 152022.1,9,12 In cases where this listing
4 includes requirements different
than those of ASHRAE 15-2022, the
appliance would need to meet the
requirements of this listing in
addition to the requirements in
ASHRAE 15-2022.
This refrigerant may only be
used in stand-alone units that meet
all requirements in UL 60335-2891,2,8 except as provided otherwise
in UL 60335-2-89, in ASHRAE 1520221,9,12, or in this listing 4. In
cases where this listing includes
requirements more stringent than
those of UL 60335-2-89, the
appliance must meet the
requirements of this listing 4 in
addition to requirements in UL
60335-2-89. Where similar
requirements of ASHRAE 15-2022
and UL 60335-2-89 differ, the more
stringent or conservative condition
shall apply unless superseded by this
listing 4.
The following markings must be
attached at the locations provided
and must be permanent:
(a) On the outside of the equipment:
“DANGER—Risk of Fire Or
Explosion. Flammable Refrigerant
Used. To Be Repaired Only By
Trained Service Personnel. Do
Not Puncture Refrigerant Tubing”

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids), 1910.110
(storage and handling of
liquefied petroleum gases),
1910.157 (portable fire
extinguishers), and 1910.1000
(toxic and hazardous
substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage of
equipment containing
flammable refrigerants through
adherence to good
manufacturing practices as per
29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment rise
above one-fourth of the lower
flammability limit, the space
should be evacuated, and
reentry should occur only after
the space has been properly
ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal protective
equipment, including chemical
goggles and protective gloves,
when handling flammable
refrigerants. Special care
should be taken to avoid
contact with the skin which,
like many refrigerants, can
cause freeze burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on equipment

(b) On the outside of the equipment:
“WARNING—Risk of Fire Or
Explosion. Dispose of Properly In
Accordance With Federal Or
Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment
near the compressor:
“DANGER—Risk of Fire OR
Explosion. Flammable Refrigerant
Used. Consult Repair
Manual/Owner’s Guide Before
Attempting to Service This
Product. All Safety Precautions
Must be Followed”
(d) For any equipment pre-charged
at the factory, on the equipment
packaging or on the outside of the
equipment: “WARNING—Risk of
Fire Due to Flammable
Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National
Regulations.”
a. If the equipment is delivered
packaged, this label shall be
applied on the packaging.
b. If the equipment is not
delivered packaged, this label
shall be applied on the outside
of the equipment near the
control panel or nameplate.
(e) On the indoor unit near the
nameplate:
a. At the top of the marking:
“Minimum Installation height,
X m (W ft).” This marking is
only required if required by UL
60335-2-89. The terms “X” and
“W” shall be replaced by the
numeric height as calculated per
UL 60335-2-89. Note that the
formatting here is slightly
different than UL 60335-2-89;
specifically, the height in InchPound units is placed in
parentheses and the word “and”
has been replaced by the
opening parenthesis.
b. Immediately below a or at the
top of the marking if a is not
required: “Minimum room area
(operating or storage), Y m2 (Z
ft2).” The terms “Y” and “Z”
shall be replaced by the numeric
area as calculated per UL
60335-2-89. Note that the
formatting here is slightly
different than UL 60335-2-89;
specifically, the area in InchPound units is placed in
parentheses and the word “and”

containing flammable
refrigerants.
Any recovery equipment
used should be designed for
flammable refrigerants. Only
technicians specifically trained
in handling flammable
refrigerants should service
refrigeration equipment
containing this refrigerant.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.
Any person commissioning,
maintaining, repairing,
decommissioning, and
disposing of appliances with
this refrigerant should obtain
training and follow practices
consistent with Annex
101.DVT of UL 60355-2-89,
2nd edition.1,2,8
Department of
Transportation requirements
for transport of flammable
gases must be followed.
Flammable refrigerants
being recovered or otherwise
disposed of from stand-alone
units are likely to be hazardous
waste under the Resource
Conservation and Recovery
Act (RCRA) (see 40 CFR
parts 260 through 270).

has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product:
“WARNING—Risk of Fire or
Explosion—Store in a wellventilated room without
continuously operating flames or
other potential ignition.”
(g) For fixed equipment that is
ducted, near the nameplate:
“WARNING—Risk Of Fire Or
Explosion—Auxiliary devices
which may be ignition sources
shall not be installed in the
ductwork, other than auxiliary
devices listed for use with the
specific appliance. See
instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (¼
inch) high.
The equipment must have red
Pantone® Matching System #185 or
RAL 3020 marked service ports,
pipes, hoses, or other devices
through which the refrigerant
passes, to indicate the use of a
flammable refrigerant. This color
must be applied at all service ports
and other parts of the system where
service puncturing or other actions
creating an opening from the
refrigerant circuit to the atmosphere
might be expected and must extend
a minimum of one (1) inch (25mm)
in both directions from such
locations and shall be replaced if
removed.
In addition to or instead of the
markings described in Clause 7.6DV
D1 of UL 60335-2-89,1,2,8 the
equipment may display the GHS
warning symbol for hazard category
1 flammable gases (black flame on a
white background in a diamond with
equal length sides with a red
border), as defined in Chapter 2.2,
Flammable Gasses, and Annex 1,
Classification and Labelling
Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised
edition1,13,14 on the following three
locations:
•
Outside of the equipment
(label (a));
•
on the appliance packaging
for a factory-charged unit or
adjacent to the control panel or

nameplate of a unit charged in
place (label (d)); and
•
in a location visible when
accessing a service port and
where service puncturing or
otherwise creating an opening
from the refrigerant circuit to the
atmosphere might be expected
(e.g., process tubes) (service
label).
The perpendicular height of the
diamond containing the GHS
warning symbol for hazard category
1 flammable gases shall be at least
15 mm (9/16 in). In addition, next to
the GHS warning symbol for hazard
category 1 flammable gases must be
text of the refrigerant safety class of
the refrigerant according to
ASHRAE 34-2022,1,9,10,11 in letters
at least one-third the height of the
diamond symbol.
5. Very low
temperature
refrigeration.
Nonmechanical
heat transfer
(New
equipment
only)

Ethane
(R-170)

Acceptable
subject to
use
conditions

This refrigerant may be used only
in new equipment specifically
designed and clearly identified for
the refrigerant (i.e., the substitute
may not be used as a conversion or
“retrofit” refrigerant for existing
equipment designed for other
refrigerants).
This refrigerant may only be used
in equipment that meets
requirements in Supplement SB to
UL 471.1,2,3 In cases where this
listing 5 of this table includes
requirements more stringent than
those of UL 471, the appliance
must meet the requirements of
listing 5 of this table in place of the
requirements in UL 471.
The charge size for the equipment
must not exceed 150 g (5.29 oz) in
each circuit.
As provided in clauses SB6.1.2 to
SB6.1.5 of UL 471,1,2,3 the
following markings must be
attached at the locations provided
and must be permanent:
(a) On or near any evaporators
that can be contacted by the
consumer: “DANGER - Risk of
Fire or Explosion. Flammable
Refrigerant Used. Do Not Use
Mechanical Devices To Defrost
Refrigerator. Do Not Puncture
Refrigerant Tubing.”
(b) Near the machine
compartment: “DANGER - Risk of
Fire or Explosion. Flammable
Refrigerant Used. To Be Repaired
Only By Trained Service

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), 1910.157
(portable fire extinguishers),
and 1910.1000 (toxic and
hazardous substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage
of equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as
per 29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment
rise above one-fourth of the
lower flammability limit, the
space should be evacuated
and re-entry should occur
only after the space has been
properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal
protective equipment,
including chemical goggles
and protective gloves, when
handling ethane. Special care
should be taken to avoid
contact with the skin since
ethane, like many

Personnel. Do Not Puncture
Refrigerant Tubing.”
(c) Near the machine
compartment: “CAUTION - Risk
of Fire or Explosion. Flammable
Refrigerant Used. Consult Repair
Manual/Owner's Guide Before
Attempting To Service This
Product. All Safety Precautions
Must be Followed.”
(d) On the exterior of the
refrigerator: “CAUTION - Risk of
Fire or Explosion. Dispose of
Properly In Accordance With
Federal Or Local Regulations.
Flammable Refrigerant Used.”
(e) Near any and all exposed
refrigerant tubing: “CAUTION Risk of Fire or Explosion Due To
Puncture Of Refrigerant Tubing;
Follow Handling Instructions
Carefully. Flammable Refrigerant
Used.”
All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high.
The refrigeration equipment must
have red, Pantone® Matching
System #185 or RAL 3020 marked
pipes, hoses, and other devices
through which the refrigerant is
serviced, typically known as the
service port, to indicate the use of a
flammable refrigerant. This color
must be present at all service ports
and where service puncturing or
otherwise creating an opening from
the refrigerant circuit to the
atmosphere might be expected
(e.g., process tubes). The color
mark must extend at least 2.5
centimeters (1 inch) from the
compressor and must be replaced if
removed.

6. Vending
machines
(New
equipment
only)

Isobutane
(R-600a),
Propane
(R-290),
R-441A

Acceptable
subject to
use
conditions

These refrigerants may be used
only in new equipment specifically
designed and clearly identified for
the refrigerants (i.e., none of these
substitutes may be used as a
conversion or “retrofit” refrigerant
for existing equipment designed for
other refrigerants). Detaching and
replacing the old refrigeration

refrigerants, can cause freeze
burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on equipment with
flammable refrigerants.
Any recovery equipment
used should be designed for
flammable refrigerants.
Any refrigerant releases
should be in a well-ventilated
area, such as outside of a
building.
Only technicians specifically
trained in handling flammable
refrigerants should service
equipment containing ethane.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely. Room occupants
should evacuate the space
immediately following the
accidental release of this
refrigerant.
If a service port is added
then refrigeration equipment
using this refrigerant should
have service aperture fittings
that differ from fittings used
in equipment or containers
using non-flammable
refrigerant. “Differ” means
that either the diameter differs
by at least 1/16 inch or the
thread direction is reversed
(i.e., right-handed vs. lefthanded). These different
fittings should be
permanently affixed to the
unit at the point of service and
maintained until the end-oflife of the unit, and should not
be accessed with an adaptor.
An example of nonmechanical heat transfer using
this refrigerant would be use in
a secondary loop of a
thermosiphon.
Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied

circuit from the outer casing of the
equipment with a new one
containing a new evaporator,
condenser, and refrigerant tubing
within the old casing is considered
“new” equipment and not a retrofit
of the old, existing equipment.
These substitutes may only be
used in equipment that meets
requirements in Supplement SA to
UL 541.1,2,5 In cases where this
listing 6 of this table includes
requirements more stringent than
those of UL 541, the appliance
must meet the requirements of this
listing 6 of this table in place of the
requirements in UL 541. The
charge size for vending machines
must not exceed 150 g (5.29 oz) in
each circuit.
As provided in clauses SA6.1.2 to
SA6.1.5 of UL 541,1,2,5 the
following markings must be
attached at the locations provided
and must be permanent:
(a) On or near any evaporators
that can be contacted by the
consumer: “DANGER - Risk of
Fire or Explosion. Flammable
Refrigerant Used. Do Not Use
Mechanical Devices To Defrost
Refrigerator. Do Not Puncture
Refrigerant Tubing.”
(b) Near the machine
compartment: “DANGER - Risk of
Fire or Explosion. Flammable
Refrigerant Used. To Be Repaired
Only By Trained Service
Personnel. Do Not Puncture
Refrigerant Tubing.”
(c) Near the machine
compartment: “CAUTION - Risk
of Fire or Explosion. Flammable
Refrigerant Used. Consult Repair
Manual/Owner's Guide Before
Attempting To Service This
Product. All Safety Precautions
Must be Followed.”
(d) On the exterior of the
refrigerator: “CAUTION - Risk of
Fire or Explosion. Dispose of
Properly In Accordance With
Federal Or Local Regulations.
Flammable Refrigerant Used.”
(e) Near any and all exposed
refrigerant tubing: “CAUTION Risk of Fire or Explosion Due To
Puncture Of Refrigerant Tubing;
Follow Handling Instructions
Carefully. Flammable Refrigerant
Used.”

petroleum gases), 1910.157
(portable fire extinguishers),
and 1910.1000 (toxic and
hazardous substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage
of equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as
per 29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment
rise above one-fourth of the
lower flammability limit, the
space should be evacuated
and re-entry should occur
only after the space has been
properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal
protective equipment,
including chemical goggles
and protective gloves, when
handling these refrigerants.
Special care should be taken
to avoid contact with the skin
since these refrigerants, like
many refrigerants, can cause
freeze burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on refrigeration
equipment with flammable
refrigerants.
Any recovery equipment
used should be designed for
flammable refrigerants.
Any refrigerant releases
should be in a well-ventilated
area, such as outside of a
building.
Only technicians
specifically trained in handling
flammable refrigerants should
service refrigeration
equipment containing these
refrigerants. Technicians
should gain an understanding
of minimizing the risk of fire
and the steps to use flammable
refrigerants safely.

7. Residential
and lightcommercial
air
conditioning
and heat
pumps—selfcontained
room air
conditioners
only
(New
equipment
only)

Propane
(R-290),
R-441A

Acceptable
subject to
use
conditions

All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high
The refrigeration equipment must
have red, Pantone® Matching
System #185 or RAL 3020 marked
pipes, hoses, and other devices
through which the refrigerant is
serviced, typically known as the
service port, to indicate the use of a
flammable refrigerant. This color
must be present at all service ports
and where service puncturing or
otherwise creating an opening from
the refrigerant circuit to the
atmosphere might be expected
(e.g., process tubes). The color
mark must extend at least 2.5
centimeters (1 inch) from the
compressor and must be replaced if
removed.
These refrigerants may be used
only in new equipment specifically
designed and clearly identified for
the refrigerants (i.e., none of these
substitutes may be used as a
conversion or “retrofit” refrigerant
for existing equipment designed for
other refrigerants).
These refrigerants may only be
used in equipment that meets
requirements in Supplement SA
and Appendices B through F of UL
484.1,2,4 In cases where listing 7 of
this table includes requirements
more stringent than those of UL
484, the appliance must meet the
requirements of this listing 7 of this
table in place of the requirements in
UL 484.
The charge size for the entire air
conditioner must not exceed the
maximum refrigerant mass
determined according to Appendix F
of UL 484 for the room size where
the air conditioner is used. The
charge size for these three
refrigerants must in no case exceed
1,000 g (35.3 oz or 2.21 pounds) of
propane or 1,000 g (35.3 oz or 2.21
pounds) of R-441A. For portable air
conditioners, the charge size must in
no case exceed 300 g (10.6 oz or
0.66 pounds) of propane or 330 g
(11.6 oz or 0.72 pounds) of R-441A.
The manufacturer must design a
charge size for the entire air
conditioner that does not exceed the
amount specified for the unit’s
cooling capacity, as specified in
table A, B, C, D, or E of this
appendix R.

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), 1910.157
(portable fire extinguishers),
and 1910.1000 (toxic and
hazardous substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage
of equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as
per 29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment
rise above one-fourth of the
lower flammability limit, the
space should be evacuated
and re-entry should occur
only after the space has been
properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal
protective equipment,
including chemical goggles
and protective gloves, when
handling these refrigerants.
Special care should be taken
to avoid contact with the skin
since these refrigerants, like
many refrigerants, can cause
freeze burns on the skin.

8. Residential
and light-

HFC-32

Acceptable
subject to

As provided in clauses SA6.1.2 to
SA6.1.5 of UL 484,1,2,4 the
following markings must be
attached at the locations provided
and must be permanent:
(a) On the outside of the air
conditioner: "DANGER- Risk of
Fire or Explosion. Flammable
Refrigerant Used. To Be
Repaired Only By Trained
Service Personnel. Do Not
Puncture Refrigerant Tubing."
(b) On the outside of the air
conditioner: “CAUTION - Risk
of Fire or Explosion. Dispose of
Properly In Accordance With
Federal Or Local Regulations.
Flammable Refrigerant Used."
(c) On the inside of the air
conditioner near the compressor:
“CAUTION - Risk of Fire or
Explosion. Flammable
Refrigerant Used. Consult
Repair Manual/Owner's Guide
Before Attempting To Service
This Product. All Safety
Precautions Must be Followed."
(d) On the outside of each portable
air conditioner: “WARNING:
Appliance shall be installed,
operated and stored in a room
with a floor area larger the “X”
m2 (Y ft2).” The value “X” on
the label must be determined
using the minimum room size in
m2 calculated using Appendix F
of UL 484. For R-441A, use a
lower flammability limit of
0.041 kg/m3 in calculations in
Appendix F of UL 484.
All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high.
The air conditioning equipment
must have red, Pantone® Matching
System #185 or RAL 3020 marked
pipes, hoses, and other devices
through which the refrigerant is
serviced, typically known as the
service port, to indicate the use of a
flammable refrigerant. This color
must be present at all service ports
and where service puncturing or
otherwise creating an opening from
the refrigerant circuit to the
atmosphere might be expected (e.g.,
process tubes). The color mark must
extend at least 2.5 centimeters (1
inch) from the compressor and must
be replaced if removed.
This refrigerant may be used
only in new equipment specifically

A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on air conditioning
equipment with flammable
refrigerants.
Any recovery equipment
used should be designed for
flammable refrigerants.
Any refrigerant releases
should be in a well-ventilated
area, such as outside of a
building.
Only technicians
specifically trained in handling
flammable refrigerants should
service air conditioning
equipment containing these
refrigerants. Technicians
should gain an understanding
of minimizing the risk of fire
and the steps to use flammable
refrigerants safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.
If a service port is added
then air conditioning
equipment using this
refrigerant should have service
aperture fittings that differ
from fittings used in
equipment or containers using
non-flammable refrigerant.
“Differ” means that either the
diameter differs by at least
1/16 inch or the thread
direction is reversed (i.e.,
right-handed vs. left-handed).
These different fittings should
be permanently affixed to the
unit at the point of service and
maintained until the end-oflife of the unit, and should not
be accessed with an adaptor.
Examples of air
conditioning equipment in this
category include window air
conditioning units, portable
room air conditioners, and
packaged terminal air
conditioners and heat pumps.

Applicable OSHA
requirements at 29 CFR part

commercial
air
conditioning
and heat
pumps—selfcontained
room air
conditioners
only
(New
equipment
only)
manufactured
from May 10,
2015, and up
to but not
including
May 30,
2023.

use
conditions

designed and clearly identified for
1910 must be followed,
the refrigerant (i.e., this substitute
including those at 29 CFR
may not be used as a conversion or
1910.94 (ventilation) and
“retrofit” refrigerant for existing
1910.106 (flammable and
equipment designed for other
combustible liquids),
refrigerants).
1910.110 (storage and
handling of liquefied
This refrigerant may only be
petroleum gases), 1910.157
used in equipment that meets all
(portable fire extinguishers),
requirements in Supplement SA
and 1910.1000 (toxic and
and Appendices B through F of UL
4841,2,4. In cases where this listing 8 hazardous substances).
Proper ventilation should
of this table includes requirements
be maintained at all times
more stringent than those of UL
during the manufacture and
484, the appliance must meet the
storage of equipment
requirements of listing 8 of this
table in place of the requirements in containing hydrocarbon
refrigerants through
UL 484.
adherence to good
The charge size for the entire air
manufacturing practices as
conditioner must not exceed the
per 29 CFR 1910.106. If
maximum refrigerant mass
determined according to Appendix refrigerant levels in the air
surrounding the equipment
F of UL 484 for the room size
rise above one-fourth of the
where the air conditioner is used.
The manufacturer must design a
lower flammability limit, the
charge size for the entire air
space should be evacuated
and re-entry should occur
conditioner that does not exceed
the amount specified for the unit’s only after the space has been
properly ventilated.
cooling capacity, as specified in
Technicians and equipment
table A, B, C, D, or E of this
manufacturers should wear
appendix.
For equipment following this listing appropriate personal
protective equipment,
8, and as provided in clauses
including chemical goggles
SA6.1.2 to SA6.1.5 of UL
and protective gloves, when
4841,2,4, the following markings
must be attached at the locations handling these refrigerants.
Special care should be taken
provided and must be
to avoid contact with the skin
permanent:
since these refrigerants, like
(a) On the outside of the air
conditioner: "DANGER- Risk of many refrigerants, can cause
freeze burns on the skin.
Fire or Explosion. Flammable
A Class B dry powder type
Refrigerant Used. To Be
fire extinguisher should be
Repaired Only By Trained
kept nearby.
Service Personnel. Do Not
Technicians should only
Puncture Refrigerant Tubing."
(b) On the outside of the air
use spark-proof tools when
conditioner: “CAUTION - Risk
working on air conditioning
of Fire or Explosion. Dispose of equipment with flammable
Properly In Accordance With
refrigerants.
Federal Or Local Regulations.
Any recovery equipment
Flammable Refrigerant Used."
used should be designed for
(c) On the inside of the air
flammable refrigerants.
Any refrigerant releases
conditioner near the compressor:
should be in a well-ventilated
“CAUTION - Risk of Fire or
area, such as outside of a
Explosion. Flammable
building.
Refrigerant Used. Consult
Only technicians specifically
Repair Manual/Owner's Guide
trained in handling
Before Attempting To Service
flammable refrigerants
This Product. All Safety
should service refrigeration
Precautions Must be Followed."
(d) On the outside of each portable
equipment containing these
air conditioner: “WARNING:
refrigerants. Technicians
Appliance shall be installed,
should gain an

operated and stored in a room
with a floor area larger the “X”
m2 (Y ft2).” The value “X” on
the label must be determined
using the minimum room size in
m2 calculated using Appendix F
of UL 484.
All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high.
The air conditioning equipment
must have red, Pantone® Matching
System (PMS) #185 marked pipes,
hoses, and other devices through
which the refrigerant is serviced,
typically known as the service port,
to indicate the use of a flammable
refrigerant. This color must be
present at all service ports and
where service puncturing or
otherwise creating an opening from
the refrigerant circuit to the
atmosphere might be expected
(e.g., process tubes). The color
mark must extend at least 2.5
centimeters (1 inch) from the
compressor and must be replaced if
removed.

9. Residential
and lightcommercial
air
conditioning
and heat
pumps—selfcontained
room air
conditioners
only
(New
equipment
only)
manufactured
from May 30,
2023 through
January 1,
2024.
10.
Residential
and lightcommercial
air
conditioning
and

HFC-32

Acceptable
subject to
use
Conditions

This refrigerant may only be
used in equipment that meets all
requirements in either:
1) Supplement SA and
Appendices B through F of UL
4841,2,4 and listing 8 of this table, or
2) UL 60335-2-401,2,7and listing
10 of this table.

HFC-32

Acceptable
subject to
use
conditions

This refrigerant may be used only in
new equipment specifically
designed and clearly identified for
the refrigerant (i.e., this substitute
may not be used as a conversion
or ‘‘retrofit’’ refrigerant for
existing equipment designed for

understanding of minimizing
the risk of fire and the steps
to use flammable
refrigerants safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.
If a service port is added then
air conditioning equipment
using this refrigerant
should have service
aperture fittings that differ
from fittings used in
equipment or containers
using non-flammable
refrigerant. “Differ” means
that either the diameter
differs by at least 1/16 inch
or the thread direction is
reversed (i.e., right-handed
vs. left-handed). These
different fittings should be
permanently affixed to the
unit at the point of service
and maintained until the
end-of-life of the unit, and
should not be accessed
with an adaptor.
Air conditioning equipment in
this category includes:
Window air conditioning units
Portable room air conditioners
Packaged terminal air
conditioners and heat pumps

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids),

heat
pumps—
self-contained
room air
conditioners
only.
(New
equipment
only)
manufactured
on or after
January 2,
2024.

other refrigerants).
This substitute may only be used
in air conditioning equipment that
meets all requirements in UL
60335-2-401,2,7 and this listing 10 of
this table.
In cases where this listing 10
includes requirements more
stringent than those of UL 603352-40, the appliance must meet the
requirements of this listing 10 in
place of the requirements in UL
60335-2-40.
The following markings must be
attached at the locations provided
and must be permanent:
(a) On the outside of the equipment:
‘‘WARNING—Risk of Fire.
Flammable Refrigerant Used. To
Be Repaired Only By Trained
Service Personnel. Do Not
Puncture Refrigerant Tubing.’’
(b) On the outside of the equipment:
‘‘WARNING—Risk of Fire.
Dispose of Properly In
Accordance With Federal Or
Local Regulations. Flammable
Refrigerant Used.’’
(c) On the inside of the equipment
near the compressor:
‘‘WARNING—Risk of Fire.
Flammable Refrigerant Used.
Consult Repair Manual/Owner’s
Guide Before Attempting to
Service This Product. All Safety
Precautions Must be Followed.’’
(d) For any equipment pre-charged
at the factory, on the equipment
packaging or on the outside of the
equipment: “WARNING—Risk of
Fire due to Flammable Refrigerant
Used. Follow Handling
Instructions Carefully in
Compliance with National
Regulations”
a. If the equipment is delivered
packaged, this label shall be
applied on the packaging.
b. If the equipment is not
delivered packaged, this label
shall be applied on the outside
of the equipment near the
control panel or nameplate.
(e) On the equipment near the
nameplate:
a. At the top of the marking:
“Minimum Installation height,
X m (W ft).” This marking is
only required if required by the
UL 60335-2-40. The terms “X”
and “W” shall be replaced by
the numeric height as calculated

1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
Proper ventilation should be
maintained at all times
during the manufacture and
storage of equipment
containing flammable
refrigerants through
adherence to good
manufacturing practices as
per 29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment
rise above one-fourth of the
lower flammability limit, the
space should be evacuated,
and reentry should occur
only after the space has been
properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal
protective equipment,
including chemical goggles
and protective gloves, when
handling flammable
refrigerants. Special care
should be taken to avoid
contact with the skin which,
like many refrigerants, can
cause freeze burns on the
skin.
A class B dry powder type fire
extinguisher should be kept
nearby.
Technicians should only use
spark-proof tools when
working on air conditioning
equipment with flammable
refrigerants.
Any recovery equipment used
should be designed for
flammable refrigerants. Only
technicians specifically
trained in handling
flammable refrigerants
should service refrigeration
equipment containing this
refrigerant. Technicians
should gain an
understanding of minimizing
the risk of fire and the steps
to use flammable
refrigerants safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.

per UL 60335-2-40. Note that
Personnel commissioning,
the formatting here is slightly
maintaining, repairing,
different than UL 60335-2-40;
decommissioning and
specifically, the height in Inchdisposing of appliances with
Pound units is placed in
this refrigerant should obtain
parentheses and the word “and”
training and follow practices
has been replaced by the
consistent with Annex HH
opening parenthesis.
of UL 60335-2-402,7.
b. Immediately below marking (a) CAA section 608(c)(2)
of this listing 8 or at the top of
prohibits knowingly venting
the marking if marking (a) is not
or otherwise knowingly
required: “Minimum room area
releasing or disposing of
(operating or storage), Y m2 (Z
substitute refrigerants in the
ft2).” The terms “Y” and “Z”
course of maintaining,
shall be replaced by the numeric
servicing, repairing or
area as calculated per UL
disposing of an appliance or
60335-2-40. Note that the
industrial process
formatting here is slightly
refrigeration.
different than UL 60335-2-40;
Department of Transportation
requirements for transport of
specifically, the area in Inchflammable gases must be
Pound units is placed in
followed.
parentheses and the word “and”
has been replaced by the
Flammable refrigerants
opening parenthesis.
being recovered or otherwise
(f) For non-fixed equipment, on the disposed of from residential
outside of the product:
and light commercial air
“WARNING—Risk of Fire or
conditioning appliances are
Explosion—Store in a welllikely to be hazardous waste
ventilated room without
under the Resource
continuously operating flames or
Conservation and Recovery
other potential ignition.”
Act (RCRA) (see 40 CFR
(g) All of these markings must be in parts 260 through 270).
letters no less than 6.4 mm (¼
inch) high.
The equipment must have red
Pantone Matching System (PMS)
#185 or RAL 3020 marked service
ports, pipes, hoses, or other devices
through which the refrigerant
passes, to indicate the use of a
flammable refrigerant. This color
must be applied at all service ports
and other parts of the system where
service puncturing or other actions
creating an opening from the
refrigerant circuit to the atmosphere
might be expected and must extend
a minimum of one (1) inch (25mm)
in both directions from such
locations and shall be replaced if
removed.
1 The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR
part 51). You may inspect a copy at the U.S. EPA or at the National Archives and Records Administration
(NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301
Constitution Avenue NW, Washington, DC 20004, https://www.epa.gov/dockets, (202) 566-1742. For
information on the availability of this material at NARA, visit https://www.archives.gov/federalregister/cfr/ibr-locations or email fr.inspection@nara.gov.
2 You may obtain the UL material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern
Avenue; Bensenville, IL 60106; phone: 1-888-853-3503 in the U.S. or Canada (other countries +1-415352-2168); email: orders@shopulstandards.com; website: https://ulstandards.ul.com or
www.shopulstandards.com.
3 UL 471. Commercial Refrigerators and Freezers. 10th edition. Supplement SB: Requirements for

Refrigerators and Freezers Employing a Flammable Refrigerant in the Refrigerating System. November 24,
2010.
4 UL 484. Room Air Conditioners. 8th edition. Supplement SA: Requirements for Room Air Conditioners
Employing a Flammable Refrigerant in the Refrigerating System and Appendices B through F. December
21, 2007, with changes through August 3, 2012.
5 UL 541. Refrigerated Vending Machines. 7th edition. Supplement SA: Requirements for Refrigerated
Venders Employing a Flammable Refrigerant in the Refrigerating System. December 30, 2011.
6 UL 60335-2-24. Standard for Safety: Requirements for Household and Similar Electrical Appliances, Safety - Part 2-24: Particular Requirements for Refrigerating Appliances, Ice-Cream Appliances and IceMakers, 2nd edition, dated April 28, 2017.
7 UL 60335-2-40, Standard for Safety: Household And Similar Electrical Appliances - Safety - Part 2- 40:
Particular Requirements for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers, 3rd edition, dated
November 1, 2019.
8 UL 60335-2-89, Standard for Safety for Household and Similar Electrical Appliances - Safety - Part 289: Particular Requirements for Commercial Refrigerating Appliances and Ice-Makers with an
Incorporated or Remote Refrigerant Unit or Motor-Compressor, 2nd edition, dated October 27, 2021.
9 You may obtain the ANSI/ASHRAE material from: American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE), 180 Technology Parkway NW, Peachtree Corners, Georgia 30092;
phone: 1-800-527-4723 or 1-404-636-8400 in the U.S. or Canada; email: cservice@ashrae.org; website:
https://www.ashrae.org/technical-resources/bookstore/ashrae-refrigeration-resources.
10 ANSI/ASHRAE Standard 34-2022. Designation and Safety Classification of Refrigerants, copyright
2022.
11 ANSI/ASHRAE Addendum a to ANSI/ASHRAE Standard 34-2022, Designation and Safety
Classification of Refrigerants, ANSI-/ASHRAE-approved December 20, 2022.
12 ANSI/ASHRAE Standard 15-2022. Safety Standard for Refrigeration Systems. copyright 2022
13 You may obtain the material from the United Nations Publications section at:
https://shop.un.org/books/global-harmon-syst-class-9-92280; United Nations Publications Customer
Service, PO Box 960, Herndon, VA 20172; phone: 1-703-661-1571; email: order@un.org.
14 ST/SG/AC.10/30/Rev.9, Global Harmonized System (GHS) of Classification and Labelling of
Chemicals, Ninth revised edition, copyright 2021; Chapter 2.2, Flammable Gasses, and Annex 1,
Classification and Labelling Summary Tables

*

*

*

*

*

4. Amend appendix V to subpart G of part 82 by:
a. Revising the heading; and
b. Revising the table titled “Refrigerants—Acceptable Subject to Use
Conditions”.
The revisions read as follows:
Appendix V to Subpart G of Part 82—Substitutes Subject to Use Restrictions and
Unacceptable Substitutes Listed in the December 1, 2016, Final Rule, Effective
January 3, 2017, and Listed in the [INSERT DATE OF PUBLICATION IN THE
FEDERAL REGISTER], Final Rule, Effective [INSERT DATE 30 DAYS AFTER
DATE OF PUBLICATION IN THE FEDERAL REGISTER]
Refrigerants—Acceptable Subject to Use Conditions
End-use
1.
Commercial
ice machines
(selfcontained)
(new only)
manufactured
from January
3, 2017, and
up to but not
including
[INSERT
DATE 30
DAYS
AFTER
DATE OF
PUBLICATI
ON IN THE
FEDERAL
REGISTER]

Substitute
Propane
(R-290)

Decision
Acceptable
subject to
use
conditions

Use Conditions
This refrigerant may be used
only in new equipment designed
specifically and clearly identified
for the refrigerant—i.e., this
refrigerant may not be used as a
conversion or “retrofit” refrigerant
for existing equipment.
This refrigerant may be used
only in self-contained commercial
ice machines that meet
requirements listed in Supplement
SA to UL 563.1,2,5 In cases where
this rule includes requirements
more stringent than those in UL
563, the equipment must meet the
requirements of the final rule in
place of the requirements in the UL
Standard.
The charge size must not exceed
150 g (5.29 oz) in each refrigerant
circuit of a commercial ice
machine.
As provided in clauses SA6.1.1
and SA6.1.2 of UL 563, the
following markings must be
attached at the locations provided
and must be permanent:
(a) “DANGER—Risk of Fire or
Explosion. Flammable
Refrigerant Used. Do Not Use
Mechanical Devices To Defrost
Refrigerator. Do Not Puncture
Refrigerant Tubing.” This

Further Information
Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation),
1910.106 (flammable and
combustible liquids), 1910.110
(storage and handling of
liquefied petroleum gases),
1910.157 (portable fire
extinguishers), and 1910.1000
(toxic and hazardous
substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage of
equipment containing
hydrocarbon refrigerants
through adherence to good
manufacturing practices as per
29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment rise
above one-fourth of the lower
flammability limit, the space
should be evacuated and reentry should occur only after
the space has been properly
ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal protective
equipment, including chemical

2.
Commercial
ice machines
(selfcontained)
(new only)
manufactured
on or after

Propane
(R-290)

Acceptable
subject to
use
conditions

marking must be provided on or
near any evaporators that can be
contacted by the consumer.
(b) “DANGER—Risk of Fire or
Explosion. Flammable
Refrigerant Used. To Be
Repaired Only By Trained
Service Personnel. Do Not
Puncture Refrigerant Tubing.”
This marking must be located
near the machine compartment.
(c) “CAUTION—Risk of Fire or
Explosion. Flammable
Refrigerant Used. Consult
Repair Manual/Owner’s Guide
Before Attempting To Service
This Product. All Safety
Precautions Must be Followed.”
This marking must be located
near the machine compartment.
(d) “CAUTION—Risk of Fire or
Explosion. Dispose of Properly
In Accordance With Federal Or
Local Regulations. Flammable
Refrigerant Used.” This
marking must be provided on
the exterior of the refrigeration
equipment.
(e) “CAUTION—Risk of Fire or
Explosion Due To Puncture Of
Refrigerant Tubing; Follow
Handling Instructions
Carefully. Flammable
Refrigerant Used.” This
marking must be provided near
all exposed refrigerant tubing.
All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high.
The equipment must have red
Pantone® Matching System #185
marked pipes, hoses, or other
devices through which the
refrigerant passes, to indicate the
use of a flammable refrigerant.
This color must be applied at all
service ports and other parts of the
system where service puncturing or
other actions creating an opening
from the refrigerant circuit to the
atmosphere might be expected and
must extend a minimum of one (1)
inch in both directions from such
locations.
This refrigerant may be used
only in self-contained commercial
ice machines that meet
requirements in either:
1. Supplement SA to UL 5631,2,5
and listing 1 of this table or
2. ASHRAE 15-2022,1,7,8 UL
60335-2-89,1,2,6 and listing 3 of

goggles and protective gloves,
when handling propane.
Special care should be taken to
avoid contact with the skin
since propane, like many
refrigerants, can cause freeze
burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on equipment with
propane.
Any recovery equipment used
should be designed for
flammable refrigerants.
Any refrigerant releases
should be in a well-ventilated
area, such as outside of a
building.
Only technicians specifically
trained in handling flammable
refrigerants should service
equipment containing propane.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely.
Room occupants should
evacuate the space
immediately following the
accidental release of this
refrigerant.
If a service port is added then,
commercial ice machines or
equipment using propane
should have service aperture
fittings that differ from fittings
used in equipment or
containers using nonflammable refrigerant. “Differ”
means that either the diameter
differs by at least 1/16 inch or
the thread direction is reversed
(i.e., right-handed vs. lefthanded). These different
fittings should be permanently
affixed to the unit at the point
of service and maintained until
the end-of-life of the unit and
should not be accessed with an
adaptor.

[INSERT
DATE 30
DAYS
AFTER
DATE OF
PUBLICATI
ON IN THE
FEDERAL
REGISTER],
through
September
29, 2024, or
equipment
manufactured
on or after
September
30, 2024, that
remains
unchanged,
other than
cosmetic
changes, from
an earlier
model or
design that
was already
certified to
the UL
5631,2,5
standard
before
September
30, 2024
3.
Commercial
ice machines
(selfcontained)
(new only)
manufactured
on or after
September
30, 2024,
except for
equipment
manufactured
on or after
September
30, 2024, that
remains
unchanged,
other than
cosmetic
changes, from
an earlier
model or
design that
was already
certified to
the UL
5631,2,5
standard

this table.

Propane
(R-290)

Acceptable
subject to
use
conditions

This refrigerant may be used
only in new equipment specifically
designed and clearly identified for
the refrigerant (i.e., none of these
substitutes may be used as a
conversion or “retrofit” refrigerant
for existing equipment designed
for other refrigerants).
This refrigerant may be used in
new commercial ice machines if
and only if such equipment meets
all requirements in ASHRAE 1520221,7,8. In cases where this listing
3 includes requirements different
than those of ASHRAE 1520221,7,8 the appliance would need
to meet the requirements of this
listing in place of the requirements
in ASHRAE 15-2022.
This refrigerant may only be
used in commercial ice machines
that meet all requirements in UL
60335-2-89,1,2,6 except as provided
otherwise in UL 60335-2-89, in
ASHRAE 15-2022, or in this
listing 3. In cases where this listing
includes requirements more
stringent than those of UL 603352-89, the appliance must meet the

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids), 1910.110
(storage and handling of
liquefied petroleum gases), and
1910.1000 (toxic and hazardous
substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage of
equipment containing
flammable refrigerants through
adherence to good
manufacturing practices as per
29 CFR 1910.106. If refrigerant
levels in the air surrounding the
equipment rise above onefourth of the lower flammability
limit, the space should be
evacuated, and reentry should
occur only after the space has
been properly ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal protective

before
September
30, 2024

requirements of this listing 3 in
place of the requirements in the UL
60335-2-89. Where similar
requirements of ASHRAE 15-2022
and UL 60335-2-89 differ, the
more stringent or conservative
condition shall apply unless
superseded by this listing 3.
The following markings must be
attached at the locations provided
and must be permanent:
(a) On the outside of the
equipment: “DANGER—Risk of
Fire Or Explosion. Flammable
Refrigerant Used. To Be
Repaired Only By Trained
Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the
equipment: “WARNING—Risk
of Fire OR Explosion. Dispose of
Properly In Accordance With
Federal Or Local Regulations.
Flammable Refrigerant Used.”
(c) On the inside of the equipment
near the compressor:
“DANGER—Risk of Fire Or
Explosion. Flammable
Refrigerant Used. Consult Repair
Manual/Owner’s Guide Before
Attempting to Service This
Product. All Safety Precautions
Must be Followed.”
(d) For any equipment pre-charged
at the factory, on the equipment
packaging or on the outside of
the equipment: “DANGER—
Risk of Fire or Explosion due to
Flammable Refrigerant Used.
Follow Handling Instructions
Carefully in Compliance with
National Regulations”
a. If the equipment is delivered
packaged, this label shall be
applied on the packaging.
b. If the equipment is not
delivered packaged, this label
shall be applied on the outside
of the equipment near the
control panel or nameplate.
(e) On indoor units near the
nameplate:
a. At the top of the marking:
“Minimum Installation Height,
X m (W ft)”. This marking is
only required if required by
UL 60335-2-89. The terms
“X” and “W” shall be replaced
by the numeric height as
calculated per UL 60335-2-89.
Note that the formatting here is
slightly different than the UL

equipment, including chemical
goggles and protective gloves,
when handling flammable
refrigerants. Special care should
be taken to avoid contact with
the skin which, like many
refrigerants, can cause freeze
burns on the skin.
A class B dry powder type
fire extinguisher should be kept
nearby.
Technicians should only use
spark-proof tools when working
on air conditioning equipment
with flammable refrigerants.
Any recovery equipment used
should be designed for
flammable refrigerants. Only
technicians specifically trained
in handling flammable
refrigerants should service
refrigeration equipment
containing this refrigerant.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely.
Room occupants should
evacuate the space immediately
following the accidental release
of this refrigerant.
Personnel commissioning,
maintaining, repairing,
decommissioning and disposing
of appliances with this
refrigerant should obtain
training and follow practices
consistent with Annex
101.DVT of UL 60355-2-89.1,2,5
Department of Transportation
requirements for transport of
flammable gases must be
followed.
Flammable refrigerants being
recovered or otherwise
disposed of from ice machine
appliances are likely to be
hazardous waste under the
Resource Conservation and
Recovery Act (RCRA) (see 40
CFR parts 260 through 270).

Standard; specifically, the
height in Inch-Pound units is
placed in parentheses and the
word “and” has been replaced
by the opening parenthesis.
b. Immediately below (a) above
or at the top of the marking if
(a) is not required: “Minimum
room area (operating or
storage), Y m2 (Z ft2)”. The
terms “Y” and “Z” shall be
replaced by the numeric area
as calculated per UL 60335-289. Note that the formatting
here is slightly different than
UL 60335-2-89; specifically,
the area in Inch-Pound units is
placed in parentheses and the
word “and” has been replaced
by the opening parenthesis.
(f) For non-fixed equipment, on the
outside of the appliance:
“WARNING—Risk of Fire or
Explosion—Store in a wellventilated room without
continuously operating flames or
other potential ignition.”
(g) For fixed equipment that is
ducted, near the nameplate:
“WARNING—Risk of Fire Or
Explosion—Auxiliary devices
which may be ignition sources
shall not be installed in the
ductwork, other than auxiliary
devices listed for use with the
specific appliance. See
instructions.”
(h) All of these markings must be
in letters no less than 6.4 mm (1⁄4
inch) high.
The equipment must have red
Pantone® Matching System #185
or RAL 3020 marked service ports,
pipes, hoses, or other devices
through which the refrigerant
passes, to indicate the use of a
flammable refrigerant. This color
must be applied at all service ports
and other parts of the system where
service puncturing or other actions
creating an opening from the
refrigerant circuit to the
atmosphere might be expected and
must extend a minimum of one (1)
inch (25 mm) in both directions
from such locations and shall be
replaced if removed.
In addition to or instead of the
markings described in Clause
7.6DV D1 of UL 60335-2-89, the
equipment may display the
Globally Harmonized System of

4. Very low
temperature
refrigeration
equipment
(new only)

Propane
(R-290)

Acceptable
subject to
use
conditions

Classification and Labelling of
Chemicals GHS warning symbol
for hazard category 1 flammable
gases (black flame on a white
background in a diamond with
equal length sides with a red
border), as defined in Chapter 2.2,
Flammable Gasses, and Annex 1,
Classification and Labelling
Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised
edition1,11,12:
• Outside of the equipment (label
(a));
• on the appliance packaging for
a factory-charged unit or
adjacent to the control panel or
nameplate of a unit charged in
place (label (d)); and
• in a location visible when
accessing a service port and
where service puncturing or
otherwise creating an opening
from the refrigerant circuit to
the atmosphere might be
expected (e.g., process tubes)
(service label).
The perpendicular height of the
diamond containing the GHS
warning symbol for hazard
category 1 flammable gases shall
be at least 15 mm (9/16 in). In
addition, next to the GHS warning
symbol for hazard category 1
flammable gases must be text of
the refrigerant safety class of the
refrigerant according to ASHRAE
34-2022,1,7,9,10 in letters at least
one-third the height of the diamond
symbol.
As of January 3, 2017:
This refrigerant may be used
only in new equipment designed
specifically and clearly identified
for the refrigerant—i.e., this
refrigerant may not be used as a
conversion or “retrofit” refrigerant
for existing equipment.
This refrigerant may only be
used in equipment that meets
requirements in Supplement SB to
UL 471.1,2,4 In cases where this
listing 4 of this table includes
requirements more stringent than
those of UL 471, the appliance
must meet the requirements of this
listing 4 of this table in place of
the requirements in UL 471.
The charge size for the

Applicable OSHA
requirements at 29 CFR part
1910 must be followed,
including those at 29 CFR
1910.94 (ventilation) and
1910.106 (flammable and
combustible liquids), 1910.110
(storage and handling of
liquefied petroleum gases),
1910.157 (portable fire
extinguishers), and 1910.1000
(toxic and hazardous
substances).
Proper ventilation should be
maintained at all times during
the manufacture and storage of
equipment containing
hydrocarbon refrigerants
through adherence to good

equipment must not exceed 150
grams (5.29 ounces) in each
refrigerant circuit of the very low
temperature refrigeration
equipment.
As provided in clauses SB6.1.2
to SB6.1.5 of UL 471, the
following markings must be
attached at the locations provided
and must be permanent:
(a) “DANGER—Risk of Fire or
Explosion. Flammable
Refrigerant Used. Do Not Use
Mechanical Devices To
Defrost Refrigerator. Do Not
Puncture Refrigerant Tubing.”
This marking must be
provided on or near any
evaporators that can be
contacted by the consumer.
(b) “DANGER—Risk of Fire or
Explosion. Flammable
Refrigerant Used. To Be
Repaired Only By Trained
Service Personnel. Do Not
Puncture Refrigerant Tubing.”
This marking must be located
near the machine
compartment.
(c) “CAUTION—Risk of Fire or
Explosion. Flammable
Refrigerant Used. Consult
Repair Manual/Owner’s Guide
Before Attempting To Service
This Product. All Safety
Precautions Must be
Followed.” This marking must
be located near the machine
compartment.
(d) “CAUTION—Risk of Fire or
Explosion. Dispose of
Properly In Accordance With
Federal Or Local Regulations.
Flammable Refrigerant Used.”
This marking must be
provided on the exterior of the
refrigeration equipment.
(e) “CAUTION—Risk of Fire or
Explosion Due To Puncture Of
Refrigerant Tubing; Follow
Handling Instructions
Carefully. Flammable
Refrigerant Used.” This
marking must be provided near
all exposed refrigerant tubing.
All of these markings must be in
letters no less than 6.4 mm (1/4
inch) high.
The equipment must have red
Pantone® Matching System #185
marked pipes, hoses, or other
devices through which the

manufacturing practices as per
29 CFR 1910.106. If
refrigerant levels in the air
surrounding the equipment rise
above one-fourth of the lower
flammability limit, the space
should be evacuated and reentry should occur only after
the space has been properly
ventilated.
Technicians and equipment
manufacturers should wear
appropriate personal protective
equipment, including chemical
goggles and protective gloves,
when handling propane.
Special care should be taken to
avoid contact with the skin
since propane, like many
refrigerants, can cause freeze
burns on the skin.
A Class B dry powder type
fire extinguisher should be
kept nearby.
Technicians should only use
spark-proof tools when
working on equipment with
flammable refrigerants.
Any recovery equipment used
should be designed for
flammable refrigerants.
Any refrigerant releases
should be in a well-ventilated
area, such as outside of a
building.
Only technicians specifically
trained in handling flammable
refrigerants should service
equipment containing propane.
Technicians should gain an
understanding of minimizing
the risk of fire and the steps to
use flammable refrigerants
safely
Room occupants should
evacuate the space immediately
following the accidental release
of this refrigerant.
If a service port is added, then
very low temperature
equipment using propane
should have service aperture
fittings that differ from fittings
used in equipment or containers
using non-flammable
refrigerant. “Differ” means that
either the diameter differs by at
least 1/16 inch or the thread
direction is reversed (i.e., righthanded vs. left-handed). These
different fittings should be
permanently affixed to the unit

refrigerant passes, to indicate the
use of a flammable refrigerant.
This color must be applied at all
service ports and other parts of the
system where service puncturing or
other actions creating an opening
from the refrigerant circuit to the
atmosphere might be expected and
must extend a minimum of one (1)
inch in both directions from such
locations.

5. Water
coolers (new
only)

Propane
(R-290)

Acceptable
subject to
use
conditions

at the point of service and
maintained until the end-of-life
of the unit, and should not be
accessed with an adaptor.
Very low temperature
equipment using propane may
also use another acceptable
refrigerant substitute in a
separate refrigerant circuit or
stage (e.g., one temperature
stage with propane and a second
stage with ethane).
This refrigerant may be used
Applicable OSHA
only in new equipment designed
requirements at 29 CFR part
specifically and clearly identified
1910 must be followed,
for the refrigerant—i.e., this
including those at 29 CFR
refrigerant may not be used as a
1910.94 (ventilation) and
conversion or “retrofit” refrigerant 1910.106 (flammable and
for existing equipment.
combustible liquids), 1910.110
This refrigerant may be used
(storage and handling of
only in water coolers that meet
liquefied petroleum gases),
requirements listed in Supplement 1910.157 (portable fire
SB to UL 3991,2,3 In cases where
extinguishers), and 1910.1000
this listing 5 includes requirements (toxic and hazardous
more stringent than those of UL
substances).
399, the appliance must meet the
Proper ventilation should be
requirements of this listing 5 in
maintained at all times during
place of the requirements in UL
the manufacture and storage of
399.
equipment containing
The charge size must not exceed hydrocarbon refrigerants
60 grams (2.12 ounces) per
through adherence to good
refrigerant circuit in the water
manufacturing practices as per
cooler.
29 CFR 1910.106. If
The equipment must have red
refrigerant levels in the air
Pantone® Matching System #185
surrounding the equipment rise
marked pipes, hoses, or other
above one-fourth of the lower
devices through which the
flammability limit, the space
refrigerant passes, to indicate the
should be evacuated and reuse of a flammable refrigerant.
entry should occur only after
This color must be applied at all
the space has been properly
service ports and other parts of the ventilated.
system where service puncturing or Technicians and equipment
other actions creating an opening
manufacturers should wear
from the refrigerant circuit to the
appropriate personal protective
atmosphere might be expected and equipment, including chemical
must extend a minimum of one (1) goggles and protective gloves,
inch in both directions from such
when handling propane.
locations.
Special care should be taken to
As provided in clauses SB6.1.2
avoid contact with the skin
to SB6.1.5 of UL 399, the
since propane, like many
following markings must be
refrigerants, can cause freeze
attached at the locations provided
burns on the skin.
and must be permanent:
A Class B dry powder type
fire extinguisher should be
(a) “DANGER—Risk of Fire or
kept nearby.
Explosion. Flammable
Technicians should only use
Refrigerant Used. Do Not Use
spark-proof tools when
Mechanical Devices To
working on equipment with
Defrost Refrigerator. Do Not
Puncture Refrigerant Tubing.” flammable refrigerants.
Any recovery equipment used
This marking must be
should be designed for
provided on or near any
flammable refrigerants.
evaporators that can be

contacted by the consumer.
Any refrigerant releases
should be in a well-ventilated
(b) “DANGER—Risk of Fire or
Explosion. Flammable
area, such as outside of a
Refrigerant Used. To Be
building.
Only technicians specifically
Repaired Only By Trained
trained in handling flammable
Service Personnel. Do Not
Puncture Refrigerant Tubing.” refrigerants should service
equipment containing propane.
This marking must be located
near the machine
Technicians should gain an
compartment.
understanding of minimizing
(c) “CAUTION—Risk of Fire or
the risk of fire and the steps to
use flammable refrigerants
Explosion. Flammable
safely.
Refrigerant Used. Consult
Repair Manual/Owner’s Guide
Room occupants should
Before Attempting To Service evacuate the space immediately
following the accidental release
This Product. All Safety
Precautions Must be
of this refrigerant.
Followed.” This marking must
If a service port is added, then
be located near the machine
water coolers or equipment
compartment.
using propane should have
(d) “CAUTION—Risk of Fire or
service aperture fittings that
Explosion. Dispose of
differ from fittings used in
Properly In Accordance With
equipment or containers using
Federal Or Local Regulations. non-flammable refrigerant.
Flammable Refrigerant Used.” “Differ” means that either the
This marking must be
diameter differs by at least 1/16
provided on the exterior of the inch or the thread direction is
refrigeration equipment.
reversed (i.e., right-handed vs.
(e) “CAUTION—Risk of Fire or
left-handed). These different
Explosion Due To Puncture Of fittings should be permanently
Refrigerant Tubing; Follow
affixed to the unit at the point of
Handling Instructions
service and maintained until the
Carefully. Flammable
end-of-life of the unit, and
Refrigerant Used.” This
should not be accessed with an
marking must be provided near adaptor.
all exposed refrigerant tubing.

The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR
part 51). You may inspect a copy at the U.S. EPA or at the National Archives and Records Administration
(NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301
Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets; (202) 202-1744. For
information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibrlocations or email fr.inspection@nara.gov.
2 You may obtain the UL material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern
Avenue; Bensenville, IL 60106; phone: 1-888-853-3503 in the U.S. or Canada (other countries +1-415352-2168); email: orders@shopulstandards.com; website: https://ulstandards.ul.com or
www.shopulstandards.com.
3 UL 399, Standard for Safety: Drinking Water Coolers- Supplement SB: Requirements for Drinking Water
Coolers Employing a Flammable Refrigerant in the Refrigerating System, 7th edition, dated August 22,
2008, including revisions through October 17, 2013.
4 UL 471, Standard for Safety: Commercial Refrigerators and Freezers. Supplement SB: Requirements for
Refrigerators and Freezers Employing a Flammable Refrigerant in the Refrigerating System, 10th edition,
dated November 24, 2010.
5 UL 563, Standard for Safety: Ice Makers. Supplement SA: Requirements for Ice Makers Employing a
Flammable Refrigerant in the Refrigerating System, 8th edition, dated July 31, 2009, including revisions
through November 29, 2013.
6 UL 60335-2-89, Standard for Safety for Household and Similar Electrical Appliances - Safety - Part 289: Particular Requirements for Commercial Refrigerating Appliances, 2nd edition, dated October 27, 2021.
7 You may obtain the ANSI/ASHRAE material from: American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE), 180 Technology Parkway NW, Peachtree Corners, Georgia 30092;
phone: 1-800-527-4723 or 1-404-636-8400 in the U.S. or Canada; email: cservice@ashrae.org; website:
https://www.ashrae.org/technical-resources/bookstore/ashrae-refrigeration-resources.
8 ANSI/ASHRAE Standard 15-2022. Safety Standard for Refrigeration Systems, copyright 2022,
9 ANSI/ASHRAE Standard 34-2022. Designation and Safety Classification of Refrigerants, copyright
2022.
10 ANSI/ASHRAE Addendum a to ANSI/ASHRAE Standard 34-2022, Designation and Safety
Classification of Refrigerants, ANSI-/ASHRAE-approved December 20, 2022.
11 You may obtain the UN material from the United Nations Publications section at:
https://shop.un.org/books/global-harmon-syst-class-9-92280; by mail: United Nations Publications
Customer Service, PO Box 960, Herndon, VA 20172; phone: 1-703-661-1571; email: order@un.org.
12 ST/SG/AC.10/30/Rev.9, Global Harmonized System (GHS) of Classification and Labelling of
Chemicals, Ninth revised edition, copyright 2021; Chapter 2.2, Flammable Gasses, and Annex 1,
Classification and Labelling Summary Tables.

*
*
*
*
*
5. Add appendix Y to subpart G of part 82 to read as follows:
Appendix Y to Subpart G of Part 82—Substitutes Listed in the [INSERT DATE OF
PUBLICATION IN THE FEDERAL REGISTER], Final Rule, Effective [INSERT
DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL
REGISTER]
REFRIGERANTS—ACCEPTABLE SUBJECT TO USE CONDITIONS
End-use
1. Retail Food
Refrigeration
—Stand-alone
units and
refrigerated
food
processing and
dispensing
equipment,
excluding
refrigerated
food
processing and
dispensing
equipment that
is within the
scope of UL
621 (Ice
Cream
Makers) (New
only)

Substitute
HFO1234yf,
HFO1234ze(E),
R-454C,
R-455A,
R-457A,
and R516A

Decision
Acceptable
subject to
use
conditions

Use Conditions
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in
stand-alone units and refrigerated food
processing and dispensing equipment if
and only if such equipment meets
requirements listed in ASHRAE 1520221,4,5 In cases where this listing
includes requirements different than those
of ASHRAE 15-2022, the appliance
would need to meet the requirements of
this listing 1 in place of the requirements
in ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 1. This listing 1 does not apply
to refrigerated food processing and
dispensing equipment that is within the
scope of UL 621 (Ice Cream Makers). In
cases where this listing includes
requirements more stringent than those of
UL 60335-2-89, the appliance must meet

Further Information
Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
It is the obligation of
regulated entitles to
inform themselves of
and comply with any
other applicable legal
obligations or
restrictions.
Proper ventilation
should be maintained at
all times during the
manufacture and
storage of equipment
containing flammable
refrigerants through
adherence to good
manufacturing practices

the requirements of this listing 1 in place
of the requirements in UL 60335-2-89.
Where similar requirements of ASHRAE
15-2022 and UL 60335-2-89 differ, the
more stringent or conservative condition
shall apply unless superseded by this
listing 1.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note

as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the
skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel

that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1⁄4 inch)
high.
The equipment must have red Pantone®
Matching System #185 or RAL 3020
marked service ports, pipes, hoses, or
other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border) as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9 on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).

commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL 603552-89.1,2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from retail
food refrigeration
appliances are likely to
be hazardous waste
under the Resource
Conservation and
Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

2. Retail Food
Refrigeration
—Refrigerated
food
processing and
dispensing
equipment
(New only)—
excluding
refrigerated
food
processing and
dispensing
equipment that
is within the
scope of UL
621 (Ice
Cream
Makers)

Propane
(R-290)

Acceptable
subject to
use
conditions

The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
This refrigerant may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
the substitute may not be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
This refrigerant may be used in
refrigerated food processing and
dispensing equipment if and only if such
equipment meets requirements listed in
ASHRAE 15-20221,4,5. In cases where this
listing 2 includes requirements different
than those of ASHRAE 15-2022, the
appliance would need to meet the
requirements of this listing 2 in place of
requirements in the ASHRAE Standard.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 2. This listing 2 does not apply
to refrigerated food processing and
dispensing equipment that is within the
scope of UL 621 (Ice Cream Makers). In
cases where this listing includes
requirements more stringent than those of
UL 60335-2-89, the appliance must meet
the requirements of this listing 2 in place
of the requirements in UL 60335-2-89.
Where similar requirements of ASHRAE
15-2022 and UL 60335-2-89 differ, the
more stringent or conservative condition
shall apply unless superseded by this
listing 2.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“DANGER—Risk of Fire Or Explosion.
Flammable Refrigerant Used. To Be
Repaired Only By Trained Service
Personnel. Do Not Puncture Refrigerant
Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire Or
Explosion. Dispose of Properly In
Accordance With Federal Or Local
Regulations. Flammable Refrigerant
Used.”
(c) On the inside of the equipment near

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
It is the obligation of
regulated entitles to
inform themselves of
and comply with any
other applicable legal
obligations or
restrictions.
Proper ventilation
should be maintained at
all times during the
manufacture and
storage of equipment
containing flammable
refrigerants through
adherence to good
manufacturing practices
as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special

the compressor: “DANGER—Risk Of
Fire Or Explosion. Flammable
Refrigerant Used. Consult Repair
Manual/Owner’s Guide Before
Attempting to Service This Product. All
Safety Precautions Must be Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“DANGER—Risk of Fire or Explosion
due to Flammable Refrigerant Used.
Follow Handling Instructions Carefully
in Compliance with National
Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire or Explosion—Auxiliary devices
which may be ignition sources shall not
be installed in the ductwork, other than
auxiliary devices listed for use with the
specific appliance. See instructions.”
(h) All of these markings must be in

care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the
skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.1,2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.

3. Retail Food
Refrigeration
—Remote
condensing
units and
supermarket
systems (New
only)

HFO1234yf,
HFO1234ze(E),
R-454A,
R-454C,
R-455A,
R-457A,
and
R-516A

Acceptable
subject to
use
conditions

letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red Pantone®
Matching System #185 or RAL 3020
marked service ports, pipes, hoses, or
other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9 on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in
remote condensing units and supermarket
systems if and only if such equipment

Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from retail
food refrigeration
appliances are likely to
be hazardous waste
under the Resource
Conservation and
Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and

meets requirements listed in ASHRAE
15-20221,4,5. In cases where this listing
includes requirements different than those
of ASHRAE 15-2022, the appliance
would need to meet the requirements of
this listing 3 in place of requirements in
the ASHRAE Standard.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 3. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance
must meet the requirements of this listing
3 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded
by this listing 3.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the

handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
It is the obligation of
regulated entitles to
inform themselves of
and comply with any
other applicable legal
obligations or
restrictions.
Proper ventilation
should be maintained at
all times during the
manufacture and storage
of equipment containing
flammable refrigerants
through adherence to
good manufacturing
practices as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in

numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red Pantone®
Matching System #185 or RAL 3020
marked service ports, pipes, hoses, or
other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25 mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global

handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.1,2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from retail
food refrigeration
appliances are likely to
be hazardous waste
under the Resource
Conservation and
Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

4. Commercial
Ice Machines
(New only)

HFO1234yf,
R-454C,
R-455A,
R-457A,
and
R-516A

Acceptable
subject to
use
conditions

Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9, on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label)
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
The substitute R-454A may only be
used in equipment with a refrigerant
charge capacity less than 200 pounds, or
in the high-temperature side of a cascade
system.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in new
commercial ice machines if and only if
such equipment meets requirements listed
in ASHRAE 15-20221,4,5. In cases where
this listing includes requirements different
than those of ASHRAE 15-2022, the
appliance would need to meet the
requirements of this listing 4 in place of
the requirements in ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 4. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance
must meet the requirements of this listing
4 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded by
this listing 4. condition shall apply unless
superseded by this listing 4.

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
It is the obligation of
regulated entitles to
inform themselves of
and comply with any
other applicable legal
obligations or
restrictions.
Proper ventilation
should be maintained at
all times during the
manufacture and storage
of equipment containing
flammable refrigerants
through adherence to
good manufacturing
practices as per 29 CFR
1910.106. If refrigerant
levels in the air

The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the

surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances

outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red
Pantone® Matching System #185 or RAL
3020 marked service ports, pipes, hoses,
or other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9, on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of

with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.1,2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from
commercial ice machine
appliances are likely to
be hazardous waste
under the Resource
Conservation and
Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

5. Commercial
Ice Machines
(New only)—
as of
[INSERT
DATE 30
DAYS
AFTER
DATE OF
PUBLICATI
ON IN THE
FEDERAL
REGISTER],
for
commercial
ice machines
with a remote
compressor,
for batch-type
self-contained
automatic
commercial
ice machines
with a harvest
rate above
1,000 lb ice
per 24 hours
and for
continuous
type selfcontained
automatic
commercial
ice machines
with a harvest
rate above
1,200 lb ice
per 24 hours;
for other
types, as of
[date reserved]

HFC-32,
R-454A,
R-454B

Acceptable
subject to
use
conditions

the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in new
commercial ice machines if and only if
such equipment meets requirements in
ASHRAE 15-20221,4,5. In cases where this
listing includes requirements different
than those of ASHRAE 15-2022, the
appliance would need to meet the
requirements of this listing 5 in place of
the requirements in ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 5. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance
must meet the requirements of this listing
5 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded by
this listing 5.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including those
at 29 CFR 1910.94
(ventilation) and
1910.106 (flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
It is the obligation of
regulated entitles to
inform themselves of and
comply with any other
applicable legal
obligations or restrictions.
Proper ventilation
should be maintained at
all times during the
manufacture and storage
of equipment containing
flammable refrigerants
through adherence to
good manufacturing
practices as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above onefourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment manufacturers
should wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special care
should be taken to avoid
contact with the skin
which, like many
refrigerants, can cause
freeze burns on the skin.
A class B dry powder
type fire extinguisher
should be kept nearby.
Technicians should
only use spark-proof tools
when working on air

packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red
Pantone® Matching System #185 or RAL
3020 marked service ports, pipes, hoses,
or other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced

conditioning equipment
with flammable
refrigerants.
Any recovery
equipment used should be
designed for flammable
refrigerants. Only
technicians specifically
trained in handling
flammable refrigerants
should service
refrigeration equipment
containing this
refrigerant. Technicians
should gain an
understanding of
minimizing the risk of fire
and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the space
immediately following the
accidental release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training and
follow practices
consistent with Annex
101.DVT of UL 2603552-89.1,2,3
CAA section 608(c)(2)
prohibits knowingly
venting or otherwise
knowingly releasing or
disposing of substitute
refrigerants in the course
of maintaining, servicing,
repairing or disposing of
an appliance or industrial
process refrigeration.
Department of
Transportation
requirements for transport
of flammable gases must
be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from
commercial ice machine
appliances are likely to be
hazardous waste under the
Resource Conservation
and Recovery Act
(RCRA) (see 40 CFR
parts 260 through 270).

6. Industrial
Process
Refrigeration
(New only)

HFC-32,
HFO1234yf,
HFO1234ze(E),
R-454A,
R-454B,
R-454C,
R-455A,
R-457A,
and
R-516A

Acceptable
subject to
use
conditions

if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9 on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in
industrial process refrigeration equipment
if and only if such equipment meets
requirements in ASHRAE 15-20221,4,5. In
cases where this listing includes
requirements different than those of
ASHRAE 15-2022, the appliance would
need to meet the requirements of this
listing 6 in place of the requirements in
ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 6. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
Proper ventilation
should be maintained at
all times during the
manufacture and storage
of equipment containing
flammable refrigerants
through adherence to
good manufacturing
practices as per 29 CFR
1910.106. If refrigerant
levels in the air

must meet the requirements of this listing
6 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded
by this listing 6.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note

surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances

that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red Pantone®
Matching System #185 or RAL 3020
marked service ports, pipes, hoses, or
other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9, on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).

with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.1,2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from
industrial process
refrigeration appliances
are likely to be
hazardous waste under
the Resource
Conservation and
Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

7. Cold
Storage
Warehouses
(New only)

HFO1234yf,
HFO1234ze(E),
R-454A,
R-454C,
R-455A,
R-457A,
and
R-516A

Acceptable
subject to
use
conditions

The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.
The substitute R-454A may only be
used in chillers for industrial process
refrigeration, in equipment with the
refrigerant temperature entering the
evaporator less than or equal to -30 °C, in
equipment with a refrigerant charge
capacity less than 200 pounds and with the
refrigerant temperature entering the
evaporator higher than -30 °C, and in the
high-temperature side of a cascade system
with the refrigerant temperature entering
the evaporator higher than -30 °C.
The substitutes HFC-32 and R-454B
may only be used in chillers for industrial
process refrigeration, or in equipment with
the refrigerant temperature entering the
evaporator less than or equal to -30 °C.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in cold
storage warehouses if and only if such
equipment meets requirements in
ASHRAE 15-20221,4,5. In cases where this
listing includes requirements different
than those of ASHRAE 15-2022, the
appliance would need to meet the
requirements of this listing 7 in place of
the requirements in ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 7. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance
must meet the requirements of this listing
7 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded
by this listing 7.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
Proper ventilation
should be maintained at
all times during the
manufacture and
storage of equipment
containing flammable
refrigerants through
adherence to good
manufacturing practices
as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.

“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in
Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other

Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the
skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on
air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.1,2,3
CAA section
608(c)(2) prohibits

potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red
Pantone® Matching System #185 or RAL
3020 marked service ports, pipes, hoses,
or other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum
of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the GHS warning symbol for hazard
category 1 flammable gases (black flame
on a white background in a diamond with
equal length sides with a red border), as
defined in Chapter 2.2, Flammable
Gasses, and Annex 1, Classification and
Labelling Summary Tables, of
ST/SG/AC.10/30/Rev.9, Global
Harmonized System (GHS) of
Classification and Labelling of
Chemicals, Ninth revised edition1,8,9, on
the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant to ASHRAE 34-2022,1,4,6,7
in letters at least one-third the height of
the diamond symbol.
The substitute R-454A may only be

knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from cold
storage warehouses are
likely to be hazardous
waste under the
Resource Conservation
and Recovery Act
(RCRA) (see 40 CFR
parts 260 through 270).

8. Ice Skating
Rinks (New
only;
Equipment
with remote
compressors)

HFO1234yf,
HFO1234ze(E),
R-454C,
R-455A,
R-457A,
and
R-516A

Acceptable
subject to
use
conditions

used either in equipment with a refrigerant
charge capacity less than 200 pounds or in
the high-temperature side of a cascade
system.
These refrigerants may be used only in
new equipment specifically designed and
clearly identified for the refrigerant (i.e.,
none of these substitutes may be used as a
conversion or “retrofit” refrigerant for
existing equipment designed for other
refrigerants).
These refrigerants may be used in ice
skating rinks with remote compressors if
and only if such equipment meets
requirements in ASHRAE 15-20221,4,5. In
cases where this listing includes
requirements different than those of
ASHRAE 15-2022, the appliance would
need to meet the requirements of this
listing 8 in place of the requirements in
ASHRAE 15-2022.
These refrigerants may only be used in
refrigeration equipment that meets all
requirements in UL 60335-2-89,1,2,3
except as provided otherwise in UL
60335-2-89, in ASHRAE 15-2022, or in
this listing 8. In cases where this listing
includes requirements more stringent than
those of UL 60335-2-89, the appliance
must meet the requirements of this listing
8 in place of the requirements in UL
60335-2-89. Where similar requirements
of ASHRAE 15-2022 and UL 60335-2-89
differ, the more stringent or conservative
condition shall apply unless superseded by
this listing 8.
The following markings must be
attached at the locations provided and
must be permanent:
(a) On the outside of the equipment:
“WARNING—Risk of Fire. Flammable
Refrigerant Used. To Be Repaired Only
By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing.”
(b) On the outside of the equipment:
“WARNING—Risk of Fire. Dispose of
Properly In Accordance With Federal
Or Local Regulations. Flammable
Refrigerant Used.”
(c) On the inside of the equipment near
the compressor: “WARNING—Risk of
Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner’s Guide
Before Attempting to Service This
Product. All Safety Precautions Must be
Followed.”
(d) For any equipment pre-charged at the
factory, on the equipment packaging or
on the outside of the equipment:
“WARNING—Risk of Fire due to
Flammable Refrigerant Used. Follow
Handling Instructions Carefully in

Applicable OSHA
requirements at 29 CFR
part 1910 must be
followed, including
those at 29 CFR
1910.94 (ventilation)
and 1910.106
(flammable and
combustible liquids),
1910.110 (storage and
handling of liquefied
petroleum gases), and
1910.1000 (toxic and
hazardous substances).
Proper ventilation
should be maintained at
all times during the
manufacture and
storage of equipment
containing flammable
refrigerants through
adherence to good
manufacturing practices
as per 29 CFR
1910.106. If refrigerant
levels in the air
surrounding the
equipment rise above
one-fourth of the lower
flammability limit, the
space should be
evacuated, and reentry
should occur only after
the space has been
properly ventilated.
Technicians and
equipment
manufacturers should
wear appropriate
personal protective
equipment, including
chemical goggles and
protective gloves, when
handling flammable
refrigerants. Special
care should be taken to
avoid contact with the
skin which, like many
refrigerants, can cause
freeze burns on the
skin.
A class B dry
powder type fire
extinguisher should be
kept nearby.
Technicians should
only use spark-proof
tools when working on

Compliance with National Regulations”
a. If the equipment is delivered
packaged, this label shall be applied
on the packaging.
b. If the equipment is not delivered
packaged, this label shall be applied
on the outside of the equipment near
the control panel or nameplate.
(e) On the equipment near the nameplate:
a. At the top of the marking: “Minimum
Installation Height, X m (W ft)”. This
marking is only required if required
by UL 60335-2-89. The terms “X”
and “W” shall be replaced by the
numeric height as calculated per the
UL Standard. Note that the formatting
here is slightly different than the UL
Standard; specifically, the height in
Inch-Pound units is placed in
parentheses and the word “and” has
been replaced by the opening
parenthesis.
b. Immediately below (a) above or at the
top of the marking if (a) is not
required: “Minimum room area
(operating or storage), Y m2 (Z ft2)”.
The terms “Y” and “Z” shall be
replaced by the numeric area as
calculated per the UL Standard. Note
that the formatting here is slightly
different than the UL Standard;
specifically, the area in Inch-Pound
units is placed in parentheses and the
word “and” has been replaced by the
opening parenthesis.
(f) For non-fixed equipment, on the
outside of the product: “WARNING—
Risk of Fire or Explosion—Store in a
well-ventilated room without
continuously operating flames or other
potential ignition.”
(g) For fixed equipment that is ducted,
near the nameplate: “WARNING—Risk
of Fire—Auxiliary devices which may
be ignition sources shall not be installed
in the ductwork, other than auxiliary
devices listed for use with the specific
appliance. See instructions.”
(h) All of these markings must be in
letters no less than 6.4 mm (1/4 inch)
high.
The equipment must have red
Pantone® Matching System #185 or RAL
3020 marked service ports, pipes, hoses,
or other devices through which the
refrigerant passes, to indicate the use of a
flammable refrigerant. This color must be
applied at all service ports and other parts
of the system where service puncturing or
other actions creating an opening from the
refrigerant circuit to the atmosphere might
be expected and must extend a minimum

air conditioning
equipment with
flammable refrigerants.
Any recovery
equipment used should
be designed for
flammable refrigerants.
Only technicians
specifically trained in
handling flammable
refrigerants should
service refrigeration
equipment containing
this refrigerant.
Technicians should gain
an understanding of
minimizing the risk of
fire and the steps to use
flammable refrigerants
safely.
Room occupants
should evacuate the
space immediately
following the accidental
release of this
refrigerant.
Personnel
commissioning,
maintaining, repairing,
decommissioning and
disposing of appliances
with this refrigerant
should obtain training
and follow practices
consistent with Annex
101.DVT of UL
260355-2-89.2,3
CAA section
608(c)(2) prohibits
knowingly venting or
otherwise knowingly
releasing or disposing
of substitute refrigerants
in the course of
maintaining, servicing,
repairing or disposing
of an appliance or
industrial process
refrigeration.
Department of
Transportation
requirements for
transport of flammable
gases must be followed.
Flammable
refrigerants being
recovered or otherwise
disposed of from ice
skating rinks are likely
to be hazardous waste
under the Resource
Conservation and

of one (1) inch (25mm) in both directions
from such locations and shall be replaced
if removed.
In addition to or instead of the markings
described in Clause 7.6DV D1 of UL
60335-2-89, the equipment may display
the Globally Harmonized System of
Classification and Labelling of Chemicals
(GHS) warning symbol for hazard
category 1 flammable gases 1,7,8 (black
flame on a white background in a
diamond with equal length sides with a
red border) on the following three
locations:
• outside of the equipment (label (a));
• on the appliance packaging for a
factory-charged unit or adjacent to the
control panel or nameplate of a unit
charged in place (label (d)); and
• in a location visible when accessing a
service port and where service
puncturing or otherwise creating an
opening from the refrigerant circuit to
the atmosphere might be expected
(e.g., process tubes) (service label).
The perpendicular height of the diamond
containing the GHS warning symbol for
hazard category 1 flammable gases shall
be at least 15 mm (9/16 in). In addition,
next to the GHS warning symbol for
hazard category 1 flammable gases must
be text of the refrigerant safety class of
the refrigerant according to ASHRAE 342022,1,4,6,7 in letters at least one-third the
height of the diamond symbol.

Recovery Act (RCRA)
(see 40 CFR parts 260
through 270).

The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR
part 51). You may inspect a copy at the U.S. EPA or at the National Archives and Records Administration
(NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301
Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets; (202) 202-1744. For information
on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or
email fr.inspection@nara.gov.
2 You may obtain the UL material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern
Avenue; Bensenville, IL 60106; phone: 1-888-853-3503 in the U.S. or Canada (other countries +1-415352-2168); email: orders@shopulstandards.com; website: https://ulstandards.ul.com or
www.shopulstandards.com.
3 UL 60335-2-89, Standard for Safety for Household and Similar Electrical Appliances - Safety - Part 289: Particular Requirements for Commercial Refrigerating Appliances, 2nd edition, dated October 27, 2021.
4 You may obtain the ANSI/ASHRAE material from: American Society of Heating, Refrigerating and AirConditioning Engineers (ASHRAE), 180 Technology Parkway NW, Peachtree Corners, Georgia 30092;
phone: 1-800-527-4723 or 1-404-636-8400 in the U.S. or Canada; email: cservice@ashrae.org; website:
https://www.ashrae.org/technical-resources/bookstore/ashrae-refrigeration-resources.
5 ANSI/ASHRAE Standard 15-2022. Safety Standard for Refrigeration Systems, copyright 2022.
6 ANSI/ASHRAE Standard 34-2022. Designation and Safety Classification of Refrigerants, copyright
2022.
7 ANSI/ASHRAE Addendum a to ANSI/ASHRAE Standard 34-2022, Designation and Safety
Classification of Refrigerants, ANSI-/ASHRAE-approved December 20, 2022.
8 You may obtain the UN material from the United Nations Publications section at:
https://shop.un.org/books/global-harmon-syst-class-9-92280; by mail: United Nations Publications
Customer Service, PO Box 960, Herndon, VA 20172; phone: 1-703-661-1571; email: order@un.org.
9 ST/SG/AC.10/30/Rev.9, Global Harmonized System (GHS) of Classification and Labelling of Chemicals,
Ninth revised edition, copyright 2021; Chapter 2.2, Flammable Gasses, and Annex 1, Classification and
Labelling Summary Tables.

[FR Doc. 2024-11690 Filed: 6/12/2024 8:45 am; Publication Date: 6/13/2024]