Document ID: EPA-HQ-OAR-2023-0043-0001
Agency: epa
Document Type: Proposed Rule
Title: Protection of Stratospheric Ozone: Listing of Substitutes under the Significant New Alternatives Policy Program in Commercial and Industrial Refrigeration
Posted Date: 2023-05-24T04:00Z

[Federal Register Volume 88, Number 100 (Wednesday, May 24, 2023)]
[Proposed Rules]
[Pages 33722-33797]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-09600]

[[Page 33721]]

Vol. 88

Wednesday,

No. 100

May 24, 2023

Part III

Environmental Protection Agency

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40 CFR Part 82

Protection of Stratospheric Ozone: Listing of Substitutes Under the 
Significant New Alternatives Policy Program in Commercial and 
Industrial Refrigeration; Proposed Rule

  Federal Register / Vol. 88 , No. 100 / Wednesday, May 24, 2023 / 
Proposed Rules  

[[Page 33722]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2023-0043; FRL-10125-1-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: Notice of proposed rulemaking.

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SUMMARY: Pursuant to the U.S. Environmental Protection Agency's 
Significant New Alternatives Policy program, this action proposes to 
list certain substances in the refrigeration and air conditioning 
sector. Specifically, EPA proposes to list 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 
proposing to incorporate 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 proposes to exempt 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, on the basis of current evidence that the 
venting, release, or disposal of this substance in this end-use does 
not pose a threat to the environment.

DATES: Comments must be received on or before July 10, 2023. Any party 
requesting a public hearing must notify the contact listed under FOR 
FURTHER INFORMATION CONTACT by 5 p.m. Eastern Daylight Time on May 30, 
2023. If a virtual public hearing is held, it will take place on or 
before June 8, 2023, and further information will be provided on EPA's 
Stratospheric Ozone website at https://www.epa.gov/snap.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2023-0043, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Mail: U.S. Environmental Protection Agency, EPA Docket 
Center, Air and Radiation Docket, Mail Code 28221T, 1200 Pennsylvania 
Avenue NW, Washington, DC 20460.
     Hand Delivery or Courier: EPA Docket Center, WJC West 
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. 
The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m., 
Monday-Friday (except Federal Holidays).
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received may be posted without change 
to https://www.regulations.gov/, including any personal information 
provided. For additional information on the rulemaking process, see the 
SUPPLEMENTARY INFORMATION section of this document.
    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 at the address above. For further 
information on EPA Docket Center services and the current status, 
please visit https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Gerald Wozniak, Stratospheric 
Protection Division, Office of Atmospheric Protection (Mail Code 
6205A), Environmental Protection Agency, 1200 Pennsylvania Ave. NW, 
Washington, DC 20460; telephone number: 202-343-9624; email address: 
[email protected]. 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/snap-regulations.

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 proposing in this action?
    A. Retail Food Refrigeration--Proposed 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 Proposed Listing of R-454A 
as Acceptable, Subject to Use Conditions, for Use in 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 proposing these specific use conditions?
    5. What additional information is EPA including in these 
proposed listings?
    6. On which topics is EPA specifically requesting comment?
    B. Retail Food Refrigeration--Proposed Listing of R-290 as 
Acceptable, Subject to Use Conditions, for Use in New Refrigerated 
Food Processing and Dispensing Equipment and Proposed Revision of 
the Use Conditions 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 proposing these specific use conditions for 
refrigerated food processing and dispensing equipment?
    5. How would the proposed listing for R-290 in refrigerated food 
processing and dispensing equipment relate to regulations 
implementing the venting prohibition under CAA section 608?
    6. What use conditions currently apply to this refrigerant in 
the stand-alone units end-use category?
    7. What updates to existing use conditions for stand-alone units 
is EPA proposing?
    8. How do the proposed use conditions for stand-alone units 
differ from the existing ones and why is EPA proposing to change the 
use conditions?
    9. What additional information is EPA including in these 
proposed listings?
    10. On which topics is EPA specifically requesting comment?
    C. Commercial Ice Machines--Proposed 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
    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 proposing these specific use conditions?
    5. What additional information is EPA including in these 
proposed listings?

[[Page 33723]]

    6. On which topics is EPA specifically requesting comment?
    D. Commercial Ice Machines--Proposed 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
    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 end-use?
    4. What use conditions currently apply to this refrigerant in 
this end-use?
    5. What updates to existing use conditions for commercial ice 
machines is EPA proposing?
    6. How do the proposed use conditions for commercial ice 
machines differ from the existing ones and why is EPA proposing to 
change the use conditions?
    7. What additional information is EPA including in this proposed 
listing?
    8. On which topics is EPA specifically requesting comment?
    E. Industrial Process Refrigeration--Proposed Listing of HFC-32, 
HFO-1234yf, HFO-1234ze(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 Idustrial 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 proposing these specific use conditions?
    5. What additional information is EPA including in these 
proposed listings?
    6. On which topics is EPA specifically requesting comment?
    F. Cold Storage Warehouses--Proposed 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
    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 proposing these specific use conditions?
    5. What additional information is EPA including in these 
proposed listings?
    6. On which topics is EPA specifically requesting comment?
    G. Ice Skating Rinks--Proposed 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
    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 proposing these specific use conditions?
    5. What additional information is EPA including in these 
proposed listings?
    6. On which topics is EPA specifically requesting comment?
    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 proposing and why?
    2. What additional information is EPA including in these 
proposed listings?
    3. On which topics is EPA specifically requesting comment?
    I. Proposed Exemption for R-290 From the Venting Prohibition 
Under CAA Section 608 for Refrigerated Food Processing and 
Dispensing Equipment
    1. What is EPA's proposed 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 proposal regarding whether venting of R-290 
from refrigerated food processing and dispensing equipment should be 
exempted from the venting prohibition under CAA section 608(c)(2)?
    3. When would the exemption from the venting prohibition apply?
    4. What is the relationship between this proposed exemption 
under CAA section 608(c)(2) and other EPA rules?
    5. On which topics is EPA specifically requesting comment?
III. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and 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 1 CFR 
Part 51
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
IV. References

I. General Information

A. Executive Summary and Background

    EPA is proposing 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 
proposing action on these new listings in the refrigeration and air 
conditioning (AC) sector based on the information that EPA has included 
in the docket. This proposed action would provide new refrigerant 
options, thereby increasing flexibility for industry, in specific uses.
    This action proposes to list new alternatives for the refrigeration 
and AC sector. Specifically, EPA is proposing to:
     List 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);
     List R-454A as acceptable, subject to use conditions, for 
use in new remote condensing units and supermarket systems;
     List R-290 (propane) as acceptable, subject to use 
conditions, for use in new refrigerated food processing and dispensing 
equipment and revise the existing use conditions for R-290 in new 
stand-alone units.
     List hydrofluorocarbon (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;
     Revise the existing use conditions for R-290 for use in 
new self-contained commercial ice machines;
     List 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 chillers for industrial process refrigeration (IPR);
     List HFC-32 and R-454B as acceptable, subject to use 
conditions, for use in new chillers for IPR;
     List 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
     List 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 using a remote compressor.
    In general, the proposed use conditions are consistent across the 
various substitutes and end-uses contained in this proposal. Because of 
this similarity, EPA discusses the proposed use conditions that would 
apply to all five end-uses in section II.H. In summary, the common use 
conditions proposed are:

[[Page 33724]]

    (1) These refrigerants may be used only in new equipment, designed 
specifically and clearly identified for use with the refrigerant. None 
of these substitutes may be used as a conversion or ``retrofit'' 
refrigerant for existing equipment.
    (2) These refrigerants may be used only in equipment that meet all 
requirements listed in the 2nd edition, dated October 27, 2021, of UL 
\1\ Standard 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'' (hereafter ``UL 60335-2-89''). 
For refrigerants that already have listings that incorporate by 
reference earlier UL standards, EPA is proposing a transition period 
when equipment may meet either the earlier UL standard or UL 60335-2-
89.
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    \1\ UL, formerly known as Underwriters Laboratories.
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    (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.
    (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) These refrigerants must be used with equipment and packaging 
marked with the Global Harmonized System of Classification and 
Labelling of Chemicals (GHS) symbol for hazard category 1 flammable 
gases.
    Additional use conditions specific to particular end-uses may also 
apply and are discussed with each proposed listing. The regulatory text 
of the proposed listings, including the proposed use conditions and 
further information, appears in tables at the end of this document. The 
proposed new listings would appear in appendix Y to 40 Code of Federal 
Regulations (CFR) part 82, subpart G. The proposed revised listings for 
R-290 in new retail food refrigeration equipment (stand-alone units 
only) and in new self-contained commercial ice machines would 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 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 is proposing to exempt R-290 used in the 
refrigerated food processing and dispensing end-use from the CAA 
section 608(c)(2) prohibition on knowingly venting, releasing, or 
disposing of substitute refrigerants on the basis of current evidence 
that the venting, release, or disposal of this substance in this end-
use does not pose a threat to the environment.
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 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 ground-level 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

[[Page 33725]]

under the SNAP program. However, regulatory requirements so listed are 
binding under other regulatory programs (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 rulemaking 
published March 18, 1994 (59 FR13044), 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 refrigerants and refrigerant substitutes 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.\2\ Section 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.
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    \2\ 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).
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    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 and their refrigerant 
substitutes, which we also refer to as the ``venting prohibition'' in 
this proposed 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 issued a rule on March 12, 2004 (69 FR 11946), and a second 
rule on April 13, 2005 (70 FR 19273), clarifying how the venting 
prohibition in section 608(c) applies to substitutes for CFC and HCFC 
refrigerants (e.g., HFCs and perfluorocarbons (PFCs)). 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 appliances may knowingly vent or otherwise release into 
the environment any refrigerant or substitute from such appliances, 
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 had 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).\3\ Those regulatory 
exemptions do not apply to blends of HCs with other refrigerants or 
containing any amount of any CFC, HCFC, HFC, or PFC. The current 
exemptions for R-290 by end-use are codified at 40 CFR 
82.154(a)(1)(viii).
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    \3\ 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 proposed rule is not EPA's response to the court's decision.
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    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., December 1, 2016 (81 FR 86778). 
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)
 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)

[[Page 33726]]

    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 the proposed 
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?

    Below is a list of acronyms and abbreviations used in the preamble 
of this document:

AC--Air Conditioning
AEL--Acceptable Exposure Limit
AIHA--American Industrial Hygiene Association
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 Heat Exchange
EPA--United States Environmental Protection Agency
FR--Federal Register
GHS--Global Harmonized System of Classification and Labelling 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
IPCC--Intergovernmental Panel on Climate Change
IPR--Industrial Process Refrigeration
ISO--International Organisation for Standardisation
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
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[supreg] Matching System
ppm--Parts Per Million
PRA--Paperwork Reduction Act
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 EPA proposing in this action?

A. Retail Food Refrigeration--Proposed 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 Proposed Listing of R-454A as Acceptable, 
Subject to Use Conditions, for Use in New Remote Condensing Units and 
Supermarkets Systems

    EPA is proposing to list 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 
proposing to list 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).
    EPA is proposing several use conditions for these end-use 
categories that are identical to those proposed for other end-uses 
(commercial ice machines, IPR, cold storage warehouses, and ice skating 
rinks with a remote compressor) discussed elsewhere in this proposal. 
Because of this similarity, EPA discusses the use conditions that would 
apply to all five end-uses in Section II.H. In summary, the common use 
conditions EPA is proposing include the following: restricting the use 
of each refrigerant to new equipment that is specifically designed for 
that refrigerant; use consistent with the 2nd edition of 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.
    For use of these substitutes in retail food refrigeration 
equipment, EPA is also proposing a use condition related to adherence 
to the American National Standards Institute (ANSI)/American Society of 
Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 
15-2022 ``Safety Standard for Refrigeration Systems'' (hereafter 
``ASHRAE 15-2022''). Specifically, we are proposing that these 
refrigerants may only be used in commercial refrigeration equipment 
that meets all requirements listed in ASHRAE 15-2022. In cases where 
the final rule includes requirements that are different than those of 
ASHRAE 15-2022, EPA is proposing that the appliance would need to meet 
the requirements of this rule in place of the requirements in ASHRAE 
15-2022. This additional use condition is discussed further in section 
II.A.4.
    EPA is also proposing the following use condition for R-454A in 
supermarkets and remote condensing units: 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.
1. Background on Retail Food Refrigeration
    Retail food refrigeration, an end-use within the SNAP program, 
encompasses the 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 comparisons of the overall impact on human health 
and the environment and of the availability of refrigerants.
    Stand-alone units are refrigerators, freezers, and reach-in coolers 
(either

[[Page 33727]]

open or with doors) where all refrigeration components are integrated 
and, for the smallest types, the refrigeration circuit is entirely 
brazed or welded. 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.
    Refrigerated food processing and dispensing equipment dispenses and 
often processes a variety of food and beverage products. For instance, 
some 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 include but 
are 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 exhibit refrigerating capacities ranging 
typically 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 walk-in 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 plurality of 
supermarkets in the United States use centralized direct expansion (DX) 
systems to cool their display cases.\4\ 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 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.
---------------------------------------------------------------------------

    \4\ www.epa.gov/greenchill/advanced-refrigeration.
---------------------------------------------------------------------------

    Indirect supermarket system designs include secondary loop systems 
and cascade refrigeration. Indirect systems use a chiller 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, air, HCs, ammonia, 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 low-
temperature 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 (R-744), in the low-temperature system, 
with a variety of refrigerants in the high temperature system.
    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 (R-717). Building 
codes from local and state agencies may also incorporate limits on the 
types and amounts of particular refrigerants used. There are and will 
continue to be multiple factors that retailers must consider when 
selecting the refrigerant and operating system design, including: 
energy efficiency; system performance; potential impact on community 
safety; ambient temperatures; risk to personnel safety; cost; and 
minimization of direct and indirect environmental impacts.
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 (TLV-TWA) 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 [deg]F (60 [deg]C) and 14.7 psia (101.3 kPa).\5\ 
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

[[Page 33728]]

less than 19,000 kJ/kg (8,169 Btu/lb), and have a lower flammability 
limit (LFL) greater than 0.10 kg/m\3\. The flammability classification 
``2L'' 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), have an LFL greater than 0.10 kg/m\3\, and have a maximum 
burning velocity of 10 cm/s or lower when tested in dry air at 73.4 
[deg]F (23.0 [deg]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/m\3\ 
or lower.
---------------------------------------------------------------------------

    \5\ ASHRAE, 2022b. ANSI/ASHRAE Standard 34-2022: Designation and 
Safety Classification of Refrigerants.
---------------------------------------------------------------------------

    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.
[GRAPHIC] [TIFF OMITTED] TP24MY23.000

    Using these safety group classifications, ASHRAE 34-2022 
categorizes HFO-1234yf, HFO-1234ze(E), HFC-32 and the refrigerant 
blends R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A, which are 
discussed in this section of this proposed 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, R-457A, 
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 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.\6\ 
The respective Chemical Abstracts Service Registry Identification 
Numbers (CAS Reg. Nos.) of HFO-1234yf, HFO-1234ze(E), and the 
components of the refrigerant blends are listed here.
---------------------------------------------------------------------------

    \6\ EPA previously listed HFO-1234yf as acceptable, subject to 
use conditions, in motor vehicle AC in light-duty 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 (HPs) (86 FR 
24444, May 6, 2021).
---------------------------------------------------------------------------

    HFO-1234yf, also known by the trade names ``Solstice[supreg] yf'' 
and ``Opteon TM YF,'' is also known as 2,3,3,3-
tetrafluoroprop-1-ene (CAS Reg. No. 754-12-1). HFO-1234ze(E), also 
known by the trade names ``Solstice[supreg] ze and Solstice[supreg] 
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[supreg] 516A,'' is a blend consisting of 77.5 percent HFO-
1234yf, 14 percent HFC-152a, and 8.5 percent HFC-134a. R-457A, also 
known by the trade name ``Forane[supreg] 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[supreg] L40X,'' is a 
blend consisting of 21.5 percent HFC-32, 75.5 percent HFO-1234yf, and 
three percent R-744 (CO2). R-454A, also known by the trade 
name ``OpteonTM XL 40,'' is a blend consisting of 35 percent 
HFC-32 and 65 percent HFO-1234yf. R-454C, also known by the trade name 
``OpteonTM 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, 
HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, and R-516A are provided 
in the docket for this proposed 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 
substitutes. These risk screens are available in the docket for this 
proposed rule.7 8 9 10 11 12 13
---------------------------------------------------------------------------

    \7\ ICF, 2023a. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: HFO-1234yf.
    \8\ ICF, 2023b. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: HFO-1234ze(E) 
(Solstice[supreg] ze, Solstice[supreg] 1234ze)
    \9\ ICF, 2023c. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: R-454A (Opteon[supreg] 
XL40).
    \10\ ICF, 2023d. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: R-454C 
(OpteonTM XL20).
    \11\ ICF, 2023e. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: R-455A (Solstice[supreg] 
L40X).
    \12\ ICF, 2023f. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: R-457A (Forane[supreg] 
457A).
    \13\ ICF, 2023g. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: R-516A (Forane[supreg] 
516A).
---------------------------------------------------------------------------

    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.

[[Page 33729]]

    HFO-1234yf has a GWP of less than four.14 15 16 HFO-
1234ze(E) has a GWP of less than six.17 18 The refrigerant 
blends are made up of the components HFC-32, HFC-125, HFC-152a, 
CO2, and HFO-1234yf, which have GWPs of 675, 3,500, 124, 
one, and less than four, respectively.\19\ If these values are weighted 
by mass percentage, then R-454A, R-454C, R-455A, R-457A, and R-516A 
have GWPs of about 240, 150, 146, 140, and 142, respectively.
---------------------------------------------------------------------------

    \14\ World Meteorological Organization (2018). Burkholder et al. 
Appendix A, Table A-1 in Scientific Assessment of Ozone Depletion: 
2018, Global Ozone Research and Monitoring Project, Report No. 58, 
World Meteorological Organization, Geneva, Switzerland, https://ozone.unep.org/science/assessment/sap. (WMO, 2018)
    \15\ 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 online at: www.cogci.dk/network/
OJN_174_CF3CF=CH2.pdf.
    \16\ Hodnebrog [Oslash]. et al., 2013. Hodnebrog [Oslash]., 
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.
    \17\ Javadi et al., 2008. Atmospheric chemistry of trans-
CF3CH=CHF: products and mechanisms of hydroxyl radical 
and chlorine atom initiated oxidation,' M.S. Javadi, R. 
S[oslash]ndergaard, O.J. Nielsen, M.D. Hurley, and T.J. Wellington, 
Atmospheric Chemistry and Physics Discussions 8, 1069-1088, 2008.
    \18\ Ibid.
    \19\ 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.
---------------------------------------------------------------------------

    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 VOC unless expressly excluded in that 
provision based on a determination of ``negligible photochemical 
reactivity.''
    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 
industrial process refrigeration, 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 
industrial process refrigeration) 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 HFO-1234yf, HFO-
1234ze(E), R-454A, R-454C, R-455A, R-457A, or R-516A.
    Flammability information: HFO-1234yf, HFO-1234ze(E), R-454A, R-
454C, R-455A, R-457A, and R-516A have lower flammability, with an 
ASHRAE flammability classification of 2L.
    Toxicity and exposure data: HFO-1234yf, HFO-1234ze(E), R-454A, R-
454C, R-455A, R-457A, and R-516A have an ASHRAE toxicity classification 
of A (lower toxicity). Potential health effects of exposure to these 
substitutes include drowsiness or dizziness. The substitutes may also 
irritate the skin or eyes or cause frostbite. At sufficiently high 
concentrations, the substitutes may cause irregular heartbeat. The 
substitutes 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 Workplace Environmental 
Exposure Limits (WEELs) of 1,000 ppm as an 8-hr TWA for HFC-32, HFC-
125, and HFC-152a; 500 ppm as an 8-hr TWA for HFO-1234yf; and 800 ppm 
as an 8-hr TWA for HFO-1234ze(E). 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.\20\ 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 
use conditions proposed (including adherence to Underwriters 
Laboratories (UL) 60335-2-89 and ASHRAE 15-2022), and other safety 
precautions common to the refrigeration and AC industry.
---------------------------------------------------------------------------

    \20\ The 8-hr TWA AEL recommendations of these refrigerant 
blends are based upon a mass-weighting of the PEL and WEELs of their 
components.
---------------------------------------------------------------------------

    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-
454A, R-454C, R-455A, R-457A, and R-516A have GWPs ranging from 140 to 
240, higher than to that of CO2, an acceptable substitute in 
this end-use category, with a GWP of 1, while HFO-1234yf and HFO-
1234ze(E) have comparable GWPs to CO2 of less than four and 
less than six, respectively. The GWPs of HFO-1234yf, HFO-1234ze(E), R-
454A, R-454C, R-455A, R-457A, and R-516A are lower than those of other 
acceptable substitutes for new refrigerated food processing and 
dispensing equipment, such as R-450A, R-513A, and HFC-134a, with GWPs 
of approximately 600, 630, and 1,430, respectively.
    For new remote condensing units and supermarket systems, R-454A, R-
454C, R-455A, R-457A, and R-516A have GWPs ranging from 140 to 240, 
higher than that of ammonia and CO2, acceptable substitutes 
in these end-use categories, with GWPs of zero and one, respectively, 
while HFO-1234yf and HFO-1234ze(E) have comparable GWPs to 
CO2 of less than four and less than six, respectively. The 
GWPs of HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, 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, HFC-134a, R-407A, and R-404A, with GWPs of approximately 
600, 630, 1,430, 2,110, and 2,630, respectively.
    For new stand-alone units, R-454A, R-454C, R-455A, R-457A, and R-
516A have GWPs ranging from 140 to 240, 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 GWPs of 
CO2, R-290, and R-441A of less than four and less than six, 
respectively. 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 stand-alone units, such as R-450A and R-513A, with 
GWPs of 601 and 630, respectively.
    Information regarding the toxicity of other available alternatives 
is provided in the listing decisions previously made (see https://
www.epa.gov/snap/retail-

[[Page 33730]]

food-refrigeration). 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 above. 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 proposed refrigerants can be minimized 
by use consistent with UL 60335-2-89--which would be required by our 
proposed use conditions--and other industry standards, such as ASHRAE 
15-2022--which applies under the use conditions--as well as 
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, R-455A, R-457A, and R-516A in these end-uses, determined by the 
likelihood of exceeding their respective lower flammability limits, are 
evaluated in the risk screens referenced above. In conclusion, 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 ASHRAE 15-2022, which would be required for 
equipment with certain charge sizes by our proposed use conditions, and 
other industry standards such as UL 60335-2-89, which would also be 
required by our proposed use conditions, as well as recommendations in 
the manufacturers' SDS and other safety precautions common in the 
refrigeration and AC industry. EPA is proposing use conditions that 
maintain the low potential risk associated with the flammability of 
these alternatives so that they will not pose significantly greater 
risk than other acceptable substitutes in this end-use category.
    In addition, the proposed substitutes have lower GWPs than most 
other available alternatives for the same uses. The proposed 
refrigerants provide 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, or where equipment using CO2 may not be able 
to meet energy conservation standards from the U.S. Department of 
Energy (DOE). 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. To provide additional options to ensure the 
availability of substitutes for the full range of retail food 
refrigeration equipment with lower GWP and, therefore, lower overall 
risk to human health and the environment, EPA is proposing the listings 
for 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 retail 
food refrigeration equipment. In addition, to account for the 
additional 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 proposing to list 
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 proposing these specific use conditions?
    This proposal applies to end-uses covered by UL 60335-2-89. This 
standard applies to commercial and industrial refrigeration equipment, 
including the SNAP end-uses of retail food refrigeration, commercial 
ice machines, IPR, cold storage warehouses, and ice skating rinks. In 
addition, ASHRAE 15-2022 applies to these refrigeration systems.
    The standard UL 60335-2-89 discussed in section II.H indicates that 
refrigerant charges greater than a specific amount (called 
``m3'' in the standard and based on the refrigerant's LFL) 
are beyond its scope and that national standards might apply, such as 
ASHRAE 15-2022. Hence, EPA is proposing to require adherence to both 
standards as use conditions for remote condensing units and supermarket 
systems, broadening the coverage under this proposed rule.
    EPA is proposing to incorporate by reference ASHRAE 15-2022, 
including all addenda published by the date of this proposal, in use 
conditions that apply to use of the proposed A2L refrigerants in new 
remote condensing units and supermarket systems. Where the requirements 
specified in this proposed rule (if finalized) and ASHRAE 15-2022 
differ, the requirements of this rule would 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. ASHRAE 15-2022 specifies requirements 
for refrigeration systems, based on the safety group classification of 
the refrigerant used, the type of occupancy in the location for which 
the system is used, and whether refrigerant-containing parts of the 
system enter the space or ductwork and so leakage in the space is 
deemed ``probable.'' ``High-probability'' installations are those such 
that leaks or failures will result in refrigerant entering occupied 
space. As previously explained, HFO-1234yf, HFO-1234ze(E), R-454A, R-
454C, R-455A, R-457A, and R-516A are all classified as A2L 
refrigerants. 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 in this proposal when 
used in ``high-probability'' systems that are not for human comfort, 
including requirements for nameplates, labels, refrigerant detectors 
(under certain conditions), airflow initiation and other actions (if a 
rise in refrigerant concentration is detected), and other restrictions.
    EPA recognizes that ASHRAE 15-2022 is undergoing continuous 
maintenance with publication of periodic addenda and is typically 
updated and republished every three years. While this proposed rule 
incorporates all addenda published by the date of this proposal, there 
may be additional changes to ASHRAE 15-2022 by the time EPA issues a 
final rule based upon this proposal. However, given EPA would not have 
reviewed and proposed use conditions based on those changes, EPA is not 
proposing to include addenda or other changes made to ASHRAE 15-2022 
after the date of the proposed rule.
    EPA is proposing to list R-454A as acceptable, subject to use 
conditions, in supermarkets and remote condensing units with a use 
condition 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 proposing this use 
condition to allow use of R-454A less broadly than for the other

[[Page 33731]]

refrigerants proposed for use in remote condensing units and 
supermarket systems because its GWP is higher than those of the other 
proposed listings for these end-use categories (about 240, compared to 
less than four to 150). EPA's understanding is that there are two 
particular situations where use of refrigerants is likely to be more 
constrained, and thus, additional refrigerant options 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 200 pounds 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 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, such as where charge sizes of 200 pounds or more of A2L 
refrigerant would be allowed under the use conditions incorporating UL 
60335-2-89 and ASHRAE 15-2022, there would be fewer space constraints 
and greater flexibility in equipment design, so refrigeration system 
designers can accommodate a narrower set of substitutes. Conversely, 
where the general public is more likely to come into contact with any 
leaked refrigerant in an interior space, refrigerant charge capacities 
of a system would be less than 200 pounds; there would be more space 
constraints, less flexibility in equipment design, and potentially 
stricter code requirements, leading to a need for more refrigerant 
options. Allowing the additional option of R-424A for supermarket 
systems and remote condensing units with smaller refrigerant charges 
would enable the use of a wider set of available substitutes to manage 
safety (in particular, flammability and toxicity), as well as allowing 
more options to achieve adequate performance where there may be more 
constraints. Therefore, EPA is proposing to list R-454A as acceptable, 
subject to use conditions, only for supermarket systems and remote 
condensing units with a refrigerant charge capacity less than 200 
pounds.
    EPA is also proposing to list R-454A as acceptable, subject to use 
conditions, for use in the high temperature side of cascade systems 
used for supermarket systems and remote condensing units. As discussed 
above in section II.A.1, ``Background on retail food refrigeration,'' 
each system of a cascade system uses a different refrigerant that is 
most suitable for the given temperature range. High 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, low boiling refrigerants 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 for 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 standards). The Agency considered whether to 
propose to list R-454A as acceptable, subject to narrowed use limits. 
For listings with narrowed use limits, the refrigerant user (e.g., 
equipment manufacturer or end user) intending to adopt a substitute 
with narrowed use limits ``must ascertain that other alternatives are 
not technically feasible.'' 40 CFR 82.180(b)(3). In the case of the 
high side of a cascade system, EPA is currently aware of a limited 
number of available options with a GWP below R-454A; therefore, EPA 
does not consider it necessary to require users to first consider those 
lower GWP refrigerants before selecting R-454A. The Agency notes that 
there are multiple substitutes available for the low temperature side 
of the cascade system with GWPs lower than that of R-454A, but there 
are few options for the high temperature side of the cascade system. 
Therefore, instead of proposing to list R-454A as acceptable, subject 
to narrowed use limits and subject to use conditions, EPA is proposing 
to list 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.
5. What additional information is EPA including in these proposed 
listings?
    EPA is providing additional information related to these proposed 
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. The additional 
information applies to multiple end-uses covered in this proposal. 
Because of this similarity, EPA discusses the proposed additional 
information in these proposed listings that would apply to all five 
end-uses in section II.H.2 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.
6. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed decision 
to list HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, and 
R-516A acceptable, subject to use conditions, in new supermarket 
systems and new remote condensing units as discussed in this section 
II.A. We also request comment on the use conditions specifically for R-
454A, restricting its use to supermarket systems and remote condensing 
units used either with a refrigerant charge capacity of less than 200 
pounds or in the high temperature side of a cascade system, and whether 
EPA should use different criteria in the final use conditions. We 
request comment on our proposal to find HFO-1234yf, HFO-1234ze(E), R-
454C, R-455A, R-457A, and R-516A acceptable, subject to use conditions, 
for use in new refrigerated food processing and dispensing equipment 
(self-contained equipment) and new stand-alone units. EPA also seeks 
specific comments on the use conditions including the proposed 
requirements to comply with UL 60335-2-89, and for charge sizes larger 
than ``m3,'' also to comply with ASHRAE 15-2022 including 
addenda as of the date of this proposal. With respect to these 
standards, EPA is requesting comment on the risk mitigation offered by 
compliance with the current version of the standards proposed as use 
conditions, i.e., UL 60335-2-89 and ASHRAE 15-2022, the nature of 
updates proposed for these standards, and the expected timeline for 
those updates. EPA is requesting comment on the applicability of the 
2nd edition of UL 60335-2-89 to retail food refrigeration equipment, 
including which types of equipment and under which

[[Page 33732]]

applications the standard applies, as well as on the applicability of 
ASHRAE 15-2022 with the addenda published as of the date of this 
proposal. Finally, EPA requests comment on whether there are any 
specific cases of conflicts between UL 60335-2-89 and ASHRAE 15-2022 
that require a clarification as to which standard should apply.

B. Retail Food Refrigeration--Proposed Listing of R-290 as Acceptable, 
Subject to Use Conditions, for Use in New Refrigerated Food Processing 
and Dispensing Equipment and Proposed Revision of Use Conditions 
Provided in the Previous Listing of R-290 as Acceptable, Subject to Use 
Conditions, for Use in Stand-Alone Units

    This proposed listing for R-290 would be a new listing for one end-
use category under retail food refrigeration, i.e., new refrigerated 
food processing and dispensing equipment. Further, EPA is also 
proposing to revise use conditions provided in the previous 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). In this document, we are 
proposing to update those use conditions to be consistent with the most 
recent U.S. national standard for retail food refrigeration equipment, 
the 2nd edition of UL 60335-2-89. Similar use conditions apply to other 
refrigerants with lower flammability as proposed in this SNAP action in 
section II.A above. The proposed use conditions would be allowed for 
such equipment manufactured on or after the effective date of any final 
rule and would not apply to nor affect equipment manufactured before 
the effective date of any final action and manufactured in compliance 
with the SNAP requirements applicable at the time of manufacture.
    This proposed revision to the use conditions would incorporate by 
reference a different industry standard, changing the reference from 
Supplement SB to the 10th edition of UL 471, ``Commercial Refrigerators 
and Freezers,'' which is required in the current SNAP listing for R-
290, to the 2nd edition of UL 60335-2-89. EPA is proposing a transition 
period during which stand-alone units manufactured with R-290 may 
follow either the earlier standard UL 471 or UL 60335-2-89. After the 
transition period ends, stand-alone units manufactured with R-290 would 
need to follow UL 60335-2-89 for purposes of the SNAP program.
    Several use conditions proposed for these end-use categories are 
similar to those proposed for other end-uses. Because of this 
similarity, EPA discusses the use conditions that would apply to all 
five end-uses in section II.H. In summary, the common use conditions 
proposed include the following: restricting the use of each refrigerant 
to new equipment that is specifically designed for that refrigerant; 
use consistent with the 2nd edition of 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.
    If the regulatory text is finalized as proposed, EPA would revise 
the existing listing for R-290 in new stand-alone units in appendix R 
to 40 CFR part 82, subpart G, and would add the new listing for R-290 
in refrigerated food processing and dispensing units in appendix Y to 
40 CFR part 82, subpart G. The proposed 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 proposing 
substantive changes to, and is not taking comment on, 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 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 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 also known as 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 proposed 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 substitute. This 
risk screen is available in the docket for this proposed rule.\21\
---------------------------------------------------------------------------

    \21\ ICF, 2023h. Risk Screen on Substitutes in Retail Food 
Refrigeration (New Equipment); Substitute: Propane (R-290).
---------------------------------------------------------------------------

    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 prohibition under CAA 
section 608(c)(2) on knowingly venting, releasing, or disposing of 
substitute refrigerants, 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 (propane) 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 below, EPA estimates that potential emissions of saturated HC 
refrigerants, such as R-290 and R-600a (isobutane), do not have a 
significant impact on local air quality.\22\
---------------------------------------------------------------------------

    \22\ ICF, 2014a. Assessment of the Potential Impact of 
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. 
February, 2014.
---------------------------------------------------------------------------

    EPA has conducted multiple analyses of various scenarios to 
consider the potential impacts on local air quality if HC refrigerants 
were used widely.\23\ 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 
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 1% of the NAAQS, and

[[Page 33733]]

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 
significantly greater risk to the environment than other alternatives. 
Using the current ozone NAAQS value of 70 ppb, use of the most reactive 
saturated HC, R-600a, with a 100% market penetration would just exceed 
a level that might raise concerns for EPA. However, considering that R-
290 is less reactive than R-600a \24\ and that R-290 would have a 
market penetration at least as high as that of R-600a,\25\ we still 
consider use of saturated HC refrigerants not to result in 
significantly greater risk.
---------------------------------------------------------------------------

    \23\ Ibid.
    \24\ R-600a has a maximum incremental reactivity (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.
---------------------------------------------------------------------------

    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 
proposed to be acceptable under this rule. For example, we assumed use 
of R-290 in refrigerated food processing and dispensing equipment \25\ 
and in end-uses where it is already listed as acceptable, including 
retail food refrigeration--stand-alone units, 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.\26\ Based on this still conservative but 
more probable assessment of refrigerant use, we found that even if all 
the refrigerant in appliances in end-uses addressed in this proposed 
rule and in appliances in end-uses 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. 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).\27\ 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.
---------------------------------------------------------------------------

    \25\ 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.
    \26\ ICF, 2014a. Assessment of the Potential Impact of 
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. 
February 2014.
    \27\ Ibid.
---------------------------------------------------------------------------

    EPA also has performed more recent air quality analyses, 
considering additional end-uses and refrigerants that have been listed 
acceptable more recently (e.g., R-1150 in very low temperature 
refrigeration) and using updated models.\28\ 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 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 proposed use conditions in this rule, would not 
result in significantly greater risk to people's health or the 
environment than other alternatives available for the same end-use, 
refrigerated food processing and dispensing equipment.
---------------------------------------------------------------------------

    \28\ ICF, 2020. 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, 2020.
---------------------------------------------------------------------------

    Based on the results of these analyses, EPA is proposing to list R-
290 as acceptable, subject to use conditions, in 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 proposed refrigerated processing and dispensing equipment 
end-use category, even in a worst-case scenario, we conclude that R-290 
does not have a significantly 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. However, the 
proposed substitute is not expected to present a flammability concern 
provided the proposed use conditions are followed.
    Toxicity and exposure data: R-290 has an ASHRAE toxicity 
classification of A (lower toxicity). Potential health effects of 
exposure to this substitute include drowsiness or dizziness. The 
substitute may also irritate the skin or eyes or cause frostbite. This 
substitute 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 propane 
(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 use conditions proposed 
(including compliance with UL 60335-2-89), adherence to ASHRAE 15-2022, 
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 3 is comparable to that of other acceptable 
substitutes for new refrigerated food processing and dispensing 
equipment, including CO2, with a GWP of 1. 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, R-
134a, 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,\29\ 
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.
---------------------------------------------------------------------------

    \29\ ICF, 2023h. Op. cit.
---------------------------------------------------------------------------

    Although we noted that the flammability of R-290 may be greater 
than that of other available, substitutes with an ASHRAE 1, 2, or 2L 
flammability classification in the same end-use, we found its 
flammability risk to be not significant even under worst-case 
assumptions in this end-use category when following the proposed

[[Page 33734]]

use conditions.\30\ We note that flammability risk can be minimized by 
use consistent with industry standards such as UL 60335-2-89--which 
would be required by our proposed use conditions--and ASHRAE 15-2022, 
as well as recommendations in the manufacturers' SDS and other safety 
precautions common in the refrigeration and air conditioning industry. 
The proposed use conditions for refrigerated food processing and 
dispensing equipment would maintain low potential risk associated with 
the flammability of this alternative so that it will not pose 
significantly greater risk than other acceptable substitutes in this 
end-use category.
---------------------------------------------------------------------------

    \30\ ICF, 2023h. Op. cit.
---------------------------------------------------------------------------

    The proposed substitute, R-290, has a GWP of 3, 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 additional, lower-GWP 
options with lower overall risk to human health and the environment, 
EPA is proposing the listing of R-290 as acceptable, subject to use 
conditions, for use in refrigerated food processing and dispensing 
equipment.
4. Why is EPA proposing these specific use conditions for refrigerated 
food processing and dispensing equipment?
    For refrigerated food processing and dispensing equipment, EPA 
proposes to require use of UL 60335-2-89, for purposes of the SNAP 
program, as of the effective date of the final rule based on this 
proposal. Several of the use conditions proposed for refrigerated food 
processing and dispensing equipment are common to those proposed for R-
290 in the commercial ice machine end-use in section II.D, and others 
are common to all five end-uses in this proposed rule. Because of this 
similarity, EPA discusses the use conditions that would apply to all 
five end-uses in section II.H. In summary, the common use conditions 
proposed include the following: restricting the use of each refrigerant 
to new equipment that is specifically designed for that refrigerant; 
use consistent with the 2nd edition of 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.
5. How would the proposed 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 document, EPA is proposing to exempt 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 industrial process refrigeration.
6. What use conditions currently apply to this refrigerant in the 
stand-alone units end-use category?
    EPA previously listed R-290 acceptable, subject to use conditions, 
in new stand-alone 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 substitutes available at that 
time for use in this end-use category. Additionally, 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 2011 listing 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 the standard 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 significantly 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 
proposing?
    EPA is proposing to update the use conditions that apply to R-290 
in new stand-alone units manufactured on or after the effective date of 
any final rule based on this proposal. Several of the updated use 
conditions proposed for use of R-290 in stand-alone units are common to 
those proposed for the commercial ice machine end-use in section II.D, 
and others are common to all five end-uses in this proposed rule. 
Because of this similarity, EPA discusses the use conditions that would 
apply to all five end-uses in section II.H. For R-290 in stand-alone 
units, these are the only revised use conditions EPA is proposing. In 
summary, with the updates proposed to the use conditions for stand-
alone units, the common use conditions proposed include the following: 
restricting the use of each refrigerant to new equipment that is 
specifically designed for that refrigerant; use consistent with the 2nd 
edition of 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.
    If finalized as proposed, the use conditions in this action would 
apply to new stand-alone units on or after the effective date of any 
final rule. Any final rule would not apply to nor affect equipment 
manufactured before the effective date of this action and manufactured 
in compliance with the SNAP use conditions applicable at the time of 
manufacture as stipulated in SNAP Rule 17 and appendix R to 40 CFR part 
82, subpart G. EPA views equipment to be manufactured at the date upon 
which the appliance's

[[Page 33735]]

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. If this rule is finalized as proposed, new stand-alone 
units manufactured between February 21, 2012, and the effective date of 
the final rule would be 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, including the use condition 
incorporating by reference Supplement SB to the 10th edition of UL 471. 
Such products would be permitted to be warehoused and sold through 
normal channels, even if they are sold or installed after the effective 
date of any final rule based on this proposed rule. Stand-alone units 
using R-290 manufactured on or after the effective date of any final 
rule based on this proposal would be required to meet the use 
conditions so finalized and listed in the revisions to appendix R. 
Those use conditions would 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 any final rule based on this proposal and would last through 
September 29, 2024. On and after September 30, 2024, the use condition 
for use of R-290 in equipment that meets UL 60335-2-89 only would apply 
under SNAP.
    EPA is proposing use conditions allowing new stand-alone units to 
be manufactured consistent with Supplement SB of UL 471, up to and 
including September 29, 2024, which is the date when UL is sunsetting 
UL 471. Therefore, during the time between the effective date of any 
final rule based on this proposal and September 29, 2024, manufacturers 
would be allowed to follow either UL 471, 10th Edition or UL 60335-2-
89, 2nd Edition. EPA is proposing 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. EPA proposes that, beginning 
September 30, 2024, R-290 may only be used in new stand-alone units 
that meet all requirements in UL 60335-2-89 for the purposes of the 
SNAP program. See section II.H.1 for further discussion on the 
requirements of this standard that EPA is proposing to incorporate by 
reference.
    In addition, we are proposing that manufacturers would need to 
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 
2 and when using UL 60335-2-89, follow all use conditions in listing 4 
in the proposed revisions to appendix R). After the transition period 
ends, stand-alone units manufactured with R-290 would need to follow UL 
60335-2-89 for purposes of the SNAP program.
    EPA also notes that we are not proposing to change two use 
conditions that currently apply, nor are we taking comment on those 
other 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 on service ports, pipes, hoses, and other 
devices through which the refrigerant is serviced, repeat the current 
use conditions for R-290 in new stand-alone units. If the regulatory 
text is finalized as proposed, EPA would amend to add use conditions 
that apply to R-290 in new stand-alone units manufactured on or after 
the effective date of the final rule. Equipment manufactured before the 
effective date of the final rule would not be affected by this action 
and would hence be subject to the current use conditions included in 
appendix R.
8. How do the proposed use conditions for stand-alone units differ from 
the existing ones and why is EPA proposing to change the use 
conditions?
    The revised use conditions EPA is proposing for stand-alone units 
are 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 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 proposed listing. The updated use conditions concern 
incorporating by reference the most recent U.S. national standard and 
updated labeling requirements consistent with that new standard. Stand-
alone units using R-290 manufactured before the effective date of a 
final rule to this proposal would not be affected by the updated use 
conditions.
    Warning labels are required under EPA's current regulations, and 
EPA is proposing to continue to require them, although with some 
specific language changes. The proposed warning labels are similar to 
those required currently as use conditions for the use of R-290 in 
stand-alone units. EPA finds that using a common set of labels, similar 
to those from UL 60335-2-89, would aid in compliance and could reduce 
burden for the industry, especially for a manufacturer that uses more 
than one refrigerant. EPA is proposing that the labels must be provided 
in letters no less than 6.4 millimeter (\1/4\ inch) high and must be 
permanent, which is identical to the current requirement for R-290 in 
stand-alone units.
    EPA is proposing to incorporate by reference a new industry 
standard in the use conditions, including use of the 2nd edition of UL 
60335-2-89 instead of continuing to require the standard Supplement SB 
of the 10th edition of UL 471 for equipment manufactured on or after 
the effective date of any final rule based on this proposal. 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. The 2nd edition of 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 more appropriately. 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 (HPs) 
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.'' In this 
document, we are proposing such a change knowing that UL is replacing 
the standard to which such equipment is certified from UL 471 to the 
newer standard UL 60335-2-89 starting September 30, 2024.
    To allow time for manufacturers of stand-alone units to transition 
between the current use condition using the 10th edition of UL 471, and 
the new use condition using the 2nd edition of UL 60335-2-89, EPA is 
proposing to allow R-290 to be used in stand-alone units manufactured 
either following UL 471 or UL 60335-2-89 during a transition period. We 
propose that transition period would begin on the effective date of the 
final rule based on this proposal

[[Page 33736]]

and would last through September 29, 2024. It is EPA's understanding 
that UL intends to sunset UL 471 on September 29, 2024, and EPA is 
proposing to coordinate with that sunset date. Beginning September 30, 
2024, the use condition in effect would only allow R-290 to be used in 
new stand-alone units that follow UL 60335-2-89. In addition, we are 
proposing that manufacturers would need to 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 proposed 
revisions to appendix R).
    Updating the UL standard incorporated as a use condition will 
provide more consistency amongst the products within the retail food 
refrigeration end-use. This change will allow the industry to focus on 
the most recent standard. The change will be helpful in implementing 
any transitions needed or planned for manufacturers, installers, and 
technicians. A manufacturer, who may offer different products within 
this end-use with different refrigerants, could use similar processes, 
such as in developing and applying the warning labels required. 
Installers and technicians, likewise, would not need to reference 
different standards depending on the type of equipment and the 
particular flammable refrigerant being used in that equipment, when 
putting in a new piece of equipment or servicing that equipment.
    Another proposed revision to the use conditions is the limit on 
charge sizes. The current use conditions from SNAP Rule 17 require the 
charge sizes calculated consistent with UL 471, with a maximum charge 
of 150 g allowed. The proposed revised use conditions for equipment 
manufactured on or after the effective date of any final rule would 
allow charge sizes calculated based on UL 60335-2-89, which allows 
charges of up to 500 g of R-290 for open stand-alone units, or 300 g 
for those with doors and drawers.
    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.\31\ In this risk 
screen, EPA adjusted charge sizes to be consistent with the larger 
charge sizes of 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. The updated risk screen found that concentrations of R-290 
still would not exceed the LFL when used according to the proposed use 
condition and consistent with UL 60335-2-89, and thus the proposed new 
use conditions would also address potential flammability risks of using 
R-290.\32\ In addition, the risk screen modeled the reasonable work 
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.\33\ 
For further information, see the risk screen in the docket for this 
rulemaking.
---------------------------------------------------------------------------

    \31\ ICF, 2023h. Op. cit.
    \32\ Ibid.
    \33\ The source of the ATEL is ASHRAE 34-2022, as cited in ICF, 
2023h. Op cit.
---------------------------------------------------------------------------

9. What additional information is EPA including in these proposed 
listings?
    EPA is providing additional information related to the proposed 
listing for R-290 in new refrigerated food processing and dispensing 
equipment and the proposed revised listing for R-290 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 
substitute under the SNAP program. See section II.H.2 for further 
discussion on what additional information EPA is including in these 
proposed listings. EPA notes that the additional information is similar 
to, but not identical with, the addition information in the listing for 
R-290 in stand-alone units in SNAP Rule 17. EPA is proposing additional 
information consistent with that included in the other proposed 
listings for 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. 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.
10. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed decision 
to list R-290 acceptable, subject to use conditions, in new 
refrigerated food processing and dispensing equipment as discussed in 
this section II.B. EPA also requests comments on the proposed change in 
use conditions for use of R-290 in stand-alone units, and if and how 
such change would affect the safety of stand-alone units using R-290. 
The Agency requests comment on the time periods during which 
manufacturers are to follow UL 471, either UL 471 or UL 60335-3-89, or 
only UL 60335-2-89. EPA also requests comments on the proposed use 
conditions for use of R-290 in new refrigerated food processing and 
dispensing equipment, including the proposed requirements to comply 
with UL 60335-2-89. With respect to this standard, EPA is requesting 
comment on the risk mitigation offered by compliance with the current 
version of the standard proposed as use conditions, i.e., UL 60335-2-
89, the nature of updates proposed for this standard, and the expected 
timeline for those updates. EPA is requesting comment on the 
applicability of the 2nd edition of UL 60335-2-89 to refrigerated food 
processing and dispensing equipment, including which types of 
equipment, under which applications the standard applies, and whether 
the listing of R-290 should apply to refrigerated food processing and 
dispensing equipment that has a remote compressor and is not self-
contained.

C. Commercial Ice Machines--Proposed 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

    EPA is proposing to list HFC-32, HFO-1234yf, 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 commercial ice 
machines.
    Several use conditions proposed for commercial ice machines are 
common to those proposed for other end-uses. Because of this 
similarity, EPA discusses the use conditions that would apply to all 
five end-uses in section II.H. For commercial ice machines, those are 
the only use conditions EPA is proposing. In summary, the common use 
conditions proposed include the following: restricting the use of each 
refrigerant to new equipment that is specifically designed for that 
refrigerant; use consistent with the 2nd edition of 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.

[[Page 33737]]

    If the regulatory text is finalized as proposed, EPA would revise 
the existing listing for R-290 in new self-contained commercial ice 
machines in appendix V to 40 CFR part 82, subpart G. The proposed 
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 proposing substantive changes to, and is not taking comment 
on, those earlier decisions (i.e., 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 machines \34\ 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 
equipment). 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.''
---------------------------------------------------------------------------

    \34\ 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.
---------------------------------------------------------------------------

    This proposal, if finalized, would list HFC-32, HFO-1234yf, R-454A, 
R-454B, R-454C, R-455A, R-457A, and R-516A as acceptable, subject to 
use conditions, in new commercial ice machines.
2. What are the ASHRAE classifications for refrigerant flammability?
    ASHRAE 34-2022 categorizes the refrigerants proposed for commercial 
ice machines in this section as being in the A2L Safety Group. See 
section II.A.2 for further discussion on ASHRAE classifications of 
these refrigerants.
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?
    See section II.A.3 for further discussion on the environmental, 
flammability, toxicity, and exposure information for HFC-32, HFO-
1234yf, R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A.\35\
---------------------------------------------------------------------------

    \35\ EPA previously listed HFO-1234yf as acceptable, subject to 
use conditions, in motor vehicle AC in light-duty 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 HPs (86 FR 24444, May 6, 
2021). EPA previously listed HFC-32 as acceptable, subject to use 
conditions, in self-contained 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.
---------------------------------------------------------------------------

    HFC-32 is also known as R-32 or difluoromethane (CAS Reg. No. 75-
10-5). R-454B, also known by the trade names ``OpteonTM XL 
41'' and ``Puron AdvanceTM,'' 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 proposed 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 substitutes. These risk screens are available in the 
docket for this proposed rule.36 37 38 
39 40 41 42 43
---------------------------------------------------------------------------

    \36\ ICF, 2023i. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: HFC-32.
    \37\ ICF, 2023j. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: HFO-1234yf.
    \38\ ICF, 2023k. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-454A (Opteon[supreg] XL40).
    \39\ ICF, 2023l. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-454B.
    \40\ ICF, 2023m. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-454C (OpteonTM 
XL20).
    \41\ ICF, 2023n. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-455A (Solstice[supreg] 
L40X).
    \42\ ICF, 2023o. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-457A (Forane[supreg] 457A).
    \43\ ICF, 2023p. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: R-516A (Forane[supreg] 516A).
---------------------------------------------------------------------------

    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 less than four, comparable to that of R-290 
and ammonia with GWPs of 3 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 commercial ice machines, including 
R-290 and ammonia with GWPs of 3 and zero, respectively, 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 such systems. Our initial evaluation is that 
the characteristics of HFC-32 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 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 proposed refrigerants can be mitigated 
by use consistent with UL 60335-2-89, 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 of HFC-32, HFO-1234yf, and the refrigerant 
blends R-454A, R-454B, R-454C, R-455A, R-

[[Page 33738]]

457A, and R-516A in the new commercial ice machine end-use, determined 
by the likelihood of exceeding their respective lower flammability 
limits, are evaluated in the risk screens referenced previously in this 
section. While these refrigerants may 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 by our proposed use 
conditions, as well as recommendations in the manufacturers' SDS and 
other safety precautions common in the refrigeration and AC industry. 
EPA is proposing use conditions to reduce the potential risk associated 
with the flammability of these alternatives so that they will not pose 
significantly greater risk than other acceptable substitutes in the new 
commercial ice machines end-use.
    In addition, the proposed substitutes have lower GWPs than most 
other available alternatives for new commercial ice machines. The 
proposed refrigerants provide 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 substitutes with lower 
GWP for the full range of new commercial ice machines and, therefore, 
lower overall risk to human health and the environment, EPA is 
proposing the listings for HFC-32, HFO-1234yf, 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 commercial ice 
machines.
4. Why is EPA proposing these specific use conditions?
    EPA is proposing to list HFC-32, HFO-1234yf, 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 commercial ice 
machines. The use conditions identified in these proposed listings are 
explained in section II.H.1 in greater detail.
5. What additional information is EPA including in these proposed 
listings?
    EPA is providing additional information related to these proposed 
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. See section II.H.2 for 
further discussion on what additional information EPA is including in 
these proposed listings. 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.
6. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed decision 
to list HFC-32, HFO-1234yf, and R-454A, R-454B, R-454C, R-455A, R-457A, 
and R-516A acceptable, subject to use conditions, in new commercial ice 
machines as discussed in this section II.C. EPA seeks comment on the 
risk mitigation offered by the proposed use conditions, including 
requiring compliance with UL 60335-2-89, except to the extent the 
proposed rule conflicts with the UL Standard, in which case we propose 
that the use conditions specified in the rule would apply. We also 
request comment on whether EPA should consider other use conditions to 
further mitigate potential risk from the proposed refrigerants in this 
end-use. EPA requests comment on whether commercial ice machines have 
been designed for or manufactured with the refrigerants proposed and 
any information on the safety of such equipment in other countries, and 
if and how such experience would translate to safe use in the United 
States.

D. Commercial Ice Machines--Proposed Revision of 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 proposing to revise use conditions in the previous listing 
of R-290 as acceptable, subject to use conditions, for use in new self-
contained commercial ice machines. More specifically, EPA previously 
listed R-290 as acceptable, subject to use conditions, in new self-
contained commercial ice machines in SNAP Rule 21 (81 FR 86779, 
December 1, 2016). In this document, we are proposing to update those 
use conditions to be consistent with the most recent U.S. national 
standard for commercial refrigeration equipment, including commercial 
ice machines, the 2nd edition of UL 60335-2-89. Similar use conditions 
would apply to other refrigerants with lower flammability as proposed 
in this SNAP action in section II.C above. The proposed revised use 
conditions would be allowed for such equipment manufactured on or after 
the effective date of any final rule and would not apply to nor affect 
equipment manufactured before the effective date of any final action 
and manufactured in compliance with the SNAP requirements applicable at 
the time of manufacture.
    This proposed revision to the use conditions would incorporate by 
reference a different industry standard, changing the reference from 
Supplement SA to the 8th edition, dated July 31, 2009, of the standard 
UL 563, ``Ice Makers'' to the 2nd edition of UL 60335-2-89. EPA is 
proposing a transition period during which self-contained commercial 
ice machines manufactured with R-290 may follow either the earlier 
standard UL 563 or UL 60335-2-89. After the transition period ends, 
self-contained commercial ice machines manufactured with R-290 would 
need to follow UL 60335-2-89 for purposes of the SNAP program.
    Several use conditions proposed for this end-use are similar to 
those proposed for other end-uses. Because of this similarity, EPA 
discusses the use conditions that would apply to all five end-uses in 
section II.H. In summary, the common use conditions proposed include 
the following: restricting the use of the refrigerant to new equipment 
that is specifically designed for that refrigerant; use consistent with 
the 2nd edition of 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 proposed decisions 
appears in tables at the end of this document.
    If the regulatory text is finalized as proposed, EPA would revise 
the existing listing for R-290 in new self-contained commercial ice 
machines in appendix V to 40 CFR part 82, subpart G. The proposed 
regulatory text contains listing decisions for new self-contained 
commercial ice machines in appendix V, as well as certain other 
previous listings that EPA is republishing for purposes of formatting 
for the Federal

[[Page 33739]]

Register; EPA is not proposing substantive changes to, and is not 
taking comment on, those earlier decisions (i.e., 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 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 for further discussion on ASHRAE classifications.
3. What is R-290 and were is there information on its use in this end-
use?
    See section II.B.3 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 proposed 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 substitute in 
self-contained commercial ice machines. The risk screen is available in 
the docket for this proposed rule.\44\
---------------------------------------------------------------------------

    \44\ ICF, 2023q. Risk Screen on Substitutes in Commercial Ice 
Machines (New Equipment); Substitute: (R-290).
---------------------------------------------------------------------------

4. What use conditions currently apply to this refrigerant in this end-
use?
    EPA previously listed R-290 acceptable, subject to use conditions, 
in new self-contained 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 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 the standard 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 substitute, 
including the risk due to flammability, was not significantly greater 
risk in this end-use than other substitutes that are currently or 
potentially available for that same end-use.
5. What updates to the existing use conditions for commercial ice 
machines is EPA proposing?
    EPA is proposing to update the use conditions that apply to R-290 
in new self-contained commercial ice machines manufactured on or after 
the effective date of any final rule based on this proposal. Several of 
the updated use conditions proposed for use of R-290 in self-contained 
commercial ice machines are common to those proposed for the stand-
alone units end-use in section II.B, and other are common to all five 
end-uses in this proposed rule. Because of this similarity, EPA 
discusses the use conditions that would apply to all five end-uses in 
section II.H. For R-290 in self-contained commercial ice machines, 
these are the only revised use conditions EPA is proposing. In summary, 
with the updates proposed to the use conditions for new self-contained 
commercial ice machines, the common use conditions proposed include the 
following: restricting the use of the refrigerant to new equipment that 
is specifically designed for that refrigerant; use consistent with the 
2nd edition of 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.
    If finalized as proposed, the use conditions in this action would 
apply to new self-contained commercial ice machines manufactured on or 
after the effective date of the final rule. Any final rule would not 
apply to nor affect equipment manufactured before the effective date of 
this action and manufactured in compliance with the SNAP use conditions 
applicable at the time of manufacture as stipulated in SNAP Rule 21 and 
appendix V to 40 CFR part 82, subpart G. 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. If this rule is finalized as proposed, new self-
contained commercial ice machines manufactured between January 3, 2017, 
and the effective date of the final rule based on this proposal would 
be 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 
would be permitted to be warehoused and sold through normal channels, 
even if they are sold or installed after the effective date of any 
final rule based on this proposed rule. Self-contained ice machines 
using R-290 manufactured on or after the effective date of any final 
rule based on this proposal through September 29, 2024, would be 
required to meet the use conditions so finalized and listed in the 
revisions to appendix V. Those use conditions would allow manufacturers 
of new self-contained commercial ice machines using R-290 to follow 
either UL 563 or UL 60335-2-89 from the effective date of any final 
rule based on this proposal and would last through September 29, 2024. 
On and after September 30, 2024, the use condition for use of R-290 in 
equipment that meets UL 60335-2-89 only would apply under SNAP.
    EPA is proposing use conditions allowing new self-contained 
commercial ice machines to be manufactured consistent with Supplement 
SA of UL 563, up to and including September 29, 2024, which is the date 
when UL is sunsetting UL 563. Therefore, during the time between the 
effective date of any final rule based on this proposal and September 
29, 2024, manufacturers would be allowed to follow either UL 563, 8th 
Edition or UL 60335-2-89, 2nd Edition. EPA is proposing allowing 
manufacturers to adhere to either

[[Page 33740]]

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. EPA proposes that, beginning 
September 30, 2024, R-290 may only be used in new self-contained 
commercial ice machines that meet all requirements in UL 60335-2-89 for 
the purposes of the SNAP program. See section II.H.1 for further 
discussion on the requirements of this standard that EPA is proposing 
to incorporate by reference.
    In addition, we are proposing that manufacturers would need to 
follow the set of use conditions that correspond with a specific UL 
standard (i.e., when using UL 563, follow all existing use conditions 
in listing 1 and when using UL 60335-2-89, follow all use conditions in 
listing 3 in the proposed revisions to appendix V). After the 
transition period ends, stand-alone units manufactured with R-290 would 
need to follow UL 60335-2-89 for purposes of the SNAP program.
    EPA also notes that we are not proposing to change two use 
conditions that currently apply, nor are we taking comment on those 
other 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 current use 
conditions for R-290 in new self-contained commercial ice machines.
    If the regulatory text is finalized as proposed, EPA would amend to 
add use conditions that apply to R-290 in new self-contained commercial 
ice machines manufactured on or after the effective date of the final 
rule. Equipment manufactured before the effective date of the final 
rule would not be affected by this action and would hence be subject to 
the current use conditions included in appendix V.
6. How do the proposed use conditions for commercial ice machines 
differ from the existing ones and why is EPA proposing to change the 
use conditions?
    The updated use conditions EPA is proposing 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 proposed 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 
proposed listing. The revised use conditions concern incorporating by 
reference the most recent U.S. national 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 a final rule based on this proposal would not be 
affected by the revised use conditions.
    Warning labels are required under EPA's current regulations, and 
EPA is proposing to continue to require them, although with some 
specific language changes. EPA is proposing warning labels that are 
identical to those required as use conditions for the use of R-290 in 
self-contained commercial ice machines. EPA finds that using a common 
set of labels, similar to those from UL 60335-2-89, would aid in 
compliance and could reduce burden for the industry, especially for a 
manufacturer that uses more than one refrigerant. EPA is proposing that 
the labels must be provided in letters no less than 6.4 millimeter (\1/
4\ inch) high and must be permanent, which is identical to the current 
requirement for R-290 in self-contained commercial ice machines.
    EPA is proposing to update the standard incorporated by reference 
in the use conditions, and after a transition period, replacing the 
requirement to follow Supplement SA of the 8th edition of UL 563 with 
the proposed requirement to adhere to the 2nd edition of UL 60335-2-89. 
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. 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 was aware of the continuing progress of UL 
Standards to address flammable refrigerants more appropriately. In this 
document, we are proposing such a change knowing that UL is replacing 
the standard to which such equipment is certified 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 current use condition using the 8th 
edition of UL 563, and the new use condition using the 2nd edition of 
UL 60335-2-89, EPA is proposing to allow 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. We propose that transition 
period would begin on the effective date of any final rule based on 
this proposal and would last through September 29, 2024. It is EPA's 
understanding that UL intends to sunset UL 563 on September 29, 2024, 
and EPA is proposing to coordinate with that sunset date. Beginning 
September 30, 2024, the use condition in effect would only allow R-290 
to be used in new self-contained commercial ice machines that follow UL 
60335-2-89. In addition, we are proposing that manufacturers would need 
to 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 proposed revisions to appendix V).
    Incorporating UL 60335-2-89 by reference in a use condition would 
allow the industry to manufacture and test refrigeration equipment 
following the most recent standard, which provides additional 
flexibility and safeguards when using flammable refrigerants. The 
transition period when equipment may follow either UL standard would be 
helpful in implementing any transitions needed or planned for 
manufacturers, installers, and technicians. A manufacturer, who may 
offer different products within this end-use with different 
refrigerants, could use similar processes, such as in developing and 
applying the warning labels required.
    Another proposed revision to the use conditions is the limit on 
charge sizes. The current use conditions from SNAP Rule 21 require the 
charge sizes from UL 563 calculated consistent with UL 563, with a 
maximum charge size of 150 g allowed. The proposed revised use 
conditions for equipment manufactured on or after the effective date of 
any final rule would allow charge sizes calculated based on UL 60335-2-
89, which would allow 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 would allow the 
use of R-290 in larger equipment than previously and would provide more 
options for industry, while maintaining 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 commercial 
ice

[[Page 33741]]

machines.\45\ In this risk screen, EPA adjusted charge sizes to be 
consistent with the larger charge sizes 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 proposed use condition and consistent with UL 60335-2-
89, and thus the proposed new use conditions would also address 
potential flammability risks of using R-290.\46\ 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.\47\ For further 
information, see the risk screen in the docket for this rulemaking.
---------------------------------------------------------------------------

    \45\ ICF, 2023q. Op. cit.
    \46\ Ibid.
    \47\ Ibid.
---------------------------------------------------------------------------

7. What additional information is EPA including in this proposed 
listing?
    EPA is providing additional information related to this proposed 
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. See section II.H.2 for 
further discussion on what additional information EPA is including in 
these proposed listings. EPA notes that the additional information is 
similar to, but not identical with, the addition information in the 
listing for R-290 in self-contained commercial ice machines in SNAP 
Rule 21. EPA is proposing additional information consistent with that 
included in the other proposed listings for stand-alone units in this 
rule and consistent with that included in the listings for R-290 as 
acceptable, subject to use conditions, in self-contained commercial ice 
machines in Rule 21. 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.
8. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed updates to 
the use conditions as discussed in this section II.D. EPA requests 
comments on the proposed change in use conditions and if and how such 
change would affect the safety of self-contained commercial ice 
machines using R-290. EPA is requesting comment on the risk mitigation 
offered by compliance with the current version of the standard proposed 
as use conditions, i.e., UL 60335-2-89, the nature of updates proposed 
for this standard, and the expected timeline for those updates. The 
Agency also requests comment on allowing a transition period where 
either of two sets of use conditions, including either UL 563 or UL 
60335-2-89, may be followed and on the specific dates for the 
transition period. EPA is requesting comment on the applicability of 
the 2nd edition of UL 60335-2-89 to new self-contained commercial ice 
machines, including which types of equipment, under which applications 
the standard applies, and whether the listing of R-290 should apply to 
commercial ice machines that have a remote compressor and are not self-
contained.

E. Industrial Process Refrigeration--Proposed Listing of HFC-32, HFO-
1234yf, HFO-1234ze(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

    EPA is proposing to list 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 industrial 
process refrigeration.
    Most of the use conditions proposed for the proposed A2L 
refrigerants when used in IPR are the same as those proposed for other 
end-uses. Because of this similarity, EPA discusses the use conditions 
that would apply to all five end-uses in section II.H. In summary, the 
common use conditions proposed include the following: restricting the 
use of each refrigerant to new equipment that is specifically designed 
for that refrigerant; use consistent with the 2nd edition of 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 following use condition also applies for R-32 and R-454B in 
industrial process refrigeration: these substitutes may only be used in 
chillers for IPR.
    The following use condition also applies for R-454A in IPR: this 
substitute may only be used either in chillers for IPR, 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 proposed decisions appears in tables at 
the end of this document. If finalized as proposed, this text would be 
codified in appendix Y to 40 CFR part 82, subpart G. The proposed 
regulatory text contains listing decisions for the end-use discussed 
above. EPA notes that there may be other legal obligations pertaining 
to the manufacture, use, handling, and disposal of the proposed 
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 substitute for specific 
applications depends on ambient and required operating temperatures and 
pressures. It is EPA's understanding that this type of equipment 
generally 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 Motor-Compressor.'' In contrast, 
industrial process air conditioning primarily cools people, may also 
cool processes, and follows a different UL standard. In addition, 
sometimes chillers are used primarily to cool process streams, rather 
than for comfort cooling. EPA describes this application as ``chillers 
in IPR.''
2. What are the ASHRAE classifications for refrigerant flammability?
    ASHRAE 34-2022 categorizes the refrigerants proposed for IPR in 
this section as being in the A2L Safety Group. See section II.A.2 for 
further discussion on ASHRAE classifications.
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?
    See section II.A.3 for further discussion on the environmental, 
flammability, toxicity, and exposure information for these 
refrigerants.

[[Page 33742]]

    The redacted submission and supporting documentation for HFC-32, 
HFO-1234yf, HFO-1234ze(E), blends R-454A, R-454B, R-454C, R-455A, R-
457A, and R-516A is provided in the docket for this proposed 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 substitutes. These risk screens are available in the docket for 
this proposed rule.48 49 50 51 52 53 54 55 56
---------------------------------------------------------------------------

    \48\ ICF, 2023r. Risk Screen on Substitutes in Industrial 
Process Refrigeration (New Equipment); Substitute: HFC-32 
(Difluoromethane).
    \49\ ICF, 2023s. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: HFO-1234yf.
    \50\ ICF, 2023t. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: HFO-1234ze(E) (Solstice[supreg] 
ze, Solstice[supreg] 1234ze).
    \51\ ICF, 2023u. Risk Screen on Substitutes in Industrial 
Process Refrigeration and Cold Storage Warehouses (New Equipment); 
Substitute: R-454A (Opteon[supreg] XL40).
    \52\ ICF, 2023v. Risk Screen on Substitutes in Industrial 
Process Refrigeration (New Equipment); Substitute: R-454B 
(Opteon[supreg] XL41).
    \53\ ICF, 2023w. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: R-454C (OpteonTM 
XL20).
    \54\ ICF, 2023x. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: R-455A (Solstice[supreg] L40X).
    \55\ ICF, 2023y. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: R-457A.
    \56\ ICF, 2023z. Risk Screen on Substitutes in Industrial 
Process Refrigeration, Cold Storage Warehouses, and Ice Skating 
Rinks (New Equipment); Substitute: R-516A.
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: HFC-32, HFO-
1234yf, HFO-1234ze(E), and 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 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.\57\
---------------------------------------------------------------------------

    \57\ WMO, 2018.
---------------------------------------------------------------------------

    HFO-1234yf and HFO-1234ze(E) have GWPs less than four and less than 
six, respectively, comparable to that of R-290 and ammonia with GWPs of 
3 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 has a GWP of 675, which is 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 refrigerant 
that have typically been employed in chillers for IPR.
    Information regarding the toxicity of other available alternatives 
is provided in the previous listing decisions for new IPR (https://www.epa.gov/snap/substitutes-industrial-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, R-454B, 
R-454C, R-455A, R-457A, and R-516A in this end-use, is evaluated in the 
risk screens referenced above. 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 the 
proposed 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, R-454B, R-454C, R-455A, R-457A, and R-516A in the IPR end-use, 
determined by the likelihood of exceeding their respective lower 
flammability limits, are evaluated in the risk screens referenced in 
this section above. 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 UL 60335-2-89, required by our proposed 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 proposing use 
conditions to reduce the potential risk associated with the 
flammability of the proposed alternatives so that they will not pose 
significantly greater risk than other acceptable substitutes in the new 
IPR end-use.
    In addition, the proposed substitutes have lower GWPs than most 
other available alternatives for the same uses. The proposed 
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 substitutes 
for the full range of IPR equipment with lower GWP and, therefore, 
lower overall risk to human health and the environment, EPA is 
proposing the listings for 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 proposing to list the refrigerants HFC-32 and R-454B 
with a use condition restricting their use to chillers in IPR. These 
refrigerants have higher GWPs than the other refrigerants EPA is 
proposing to list as acceptable, subject to use conditions; lower GWPs 
than many currently listed acceptable substitutes for IPR that are 
commonly in use; and lower flammability than HC refrigerants currently 
listed as acceptable in IPR. 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.
    EPA is also proposing to list 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, or in the high temperature side of a cascade system. 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 ice skating 
rinks with moderate charge sizes and for cascade systems, EPA is 
proposing to list R-454A as acceptable, subject to use conditions, for 
use in new ice skating rinks with a charge size capacity less than 200 
pounds or for use

[[Page 33743]]

in the high-temperature side of a cascade system.
4. Why is EPA proposing these specific use conditions?
    The use conditions identified in the proposed listings above for 
all nine refrigerants are explained in section II.H.1 in greater 
detail.
    EPA is proposing the use condition for HFC-32 and R-454B 
restricting their use to chillers for IPR because these substitutes 
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), EPA is 
proposing to list these two additional refrigerants to provide 
additional options and to address a broader range of equipment and 
applications. EPA also is proposing a use condition for R-454A that 
would allow its use in chillers for IPR, as well as other certain other 
applications, as described below in this section. In addition, the 
Agency previously listed HFC-32, R-454A, and R-454B as acceptable, 
subject to use conditions, in centrifugal and positive displacement 
chillers for comfort cooling in SNAP Rule 25. EPA is proposing to list 
the same refrigerants the same way for the same type of equipment 
(chillers) because of similar technical issues, such as volumetric 
capacity and operating pressure, which restrict the technical viability 
of alternatives for some applications.
    EPA is proposing to list R-454A as acceptable, subject to use 
conditions, in IPR with a use condition that this substitute may only 
be used in chillers for IPR, in equipment with a refrigerant charge 
capacity less than 200 pounds or in the high-temperature side of a 
cascade system. EPA is proposing to allow use of R-454A for use in 
chillers for IPR for the same reasons as above for HFC-32 and R-454B. 
The Agency is also proposing this use condition to allow use of R-454A 
less broadly than for the refrigerants HFO-1234yf, HFO-1234ze(E), R-
454C, R-455A, R-457A, and R-516A because its GWP is higher than those 
other proposed listings for non-chiller IPR equipment (that has a GWP 
of about 240, compared to less than four to 150). EPA's understanding 
is that, in addition to the technical constraints for refrigerant in 
chillers, there are two more situations where use of refrigerants is 
likely to be more constrained, and thus, additional refrigerant options 
may be helpful. The first of those situations is in what 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 200 pounds for 
applications inside an occupied space where people might be located. 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 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, such as 
where charge sizes of 200 pounds or more of A2L refrigerant would be 
allowed under the use conditions incorporating UL 60335-2-89 and ASHRAE 
15-2022, there would be fewer space constraints and greater flexibility 
in equipment design, so refrigeration system designers can accommodate 
a narrower set of substitutes. Conversely, where people are more likely 
to come into contact with any leaked refrigerant in an interior space, 
refrigerant charge capacities of a system would be less than 200 
pounds; there would be more space constraints, less flexibility in 
equipment design, and potentially stricter code requirements, leading 
to a need for more refrigerant options. Allowing the additional option 
of R-424A for non-chiller IPR equipment with smaller refrigerant 
charges would enable the use of a wider set of available substitutes to 
manage safety (in particular, flammability and toxicity), as well as 
allowing more options to achieve adequate performance where there may 
be more constraints. Therefore, EPA is proposing to list R-454A as 
acceptable, subject to use conditions, only for non-chiller IPR 
equipment with a refrigerant charge capacity less than 200 pounds.
    EPA is also proposing to list R-454A as acceptable, subject to use 
conditions, for use in the high temperature side of cascade systems 
used for non-chiller IPR equipment. As discussed above in section 
II.A.1, ``Background on retail food refrigeration,'' each system 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, low boiling 
refrigerants 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 standards). EPA notes that there 
are a number of substitutes available for the low temperature side of 
the cascade system with GWPs lower than that of R-454A. Therefore, 
instead of proposing to list R-454A as acceptable, subject to narrowed 
use limits and subject to use conditions, EPA is proposing to list 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.
5. What additional information is EPA including in these proposed 
listings?
    EPA is providing additional information related to these proposed 
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. See section II.H.2 for 
further discussion on what additional information EPA is including in 
these proposed listings. 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.
6. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed decision 
to list HFC-32, HFO-1234yf, HFO-1234ze(E), and the refrigerant blends 
R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A acceptable, subject 
to use conditions, in IPR as discussed in this section II.E. EPA seeks 
comment on the risk mitigation offered by the proposed use conditions, 
including requiring compliance with the 2nd edition of UL 60335-2-89, 
except to the extent the proposed rule conflicts with the UL standard, 
in which case we propose that the conditions specified in the rule 
would apply. We also request comment

[[Page 33744]]

on whether other use conditions would offer needed risk mitigation for 
the flammable refrigerants proposed. EPA requests comment on whether 
types of IPR equipment have been designed for the refrigerants 
proposed; any information on the safety of such equipment in other 
countries; and if and how such experience would translate to safe use 
in the United States. The Agency requests comment on whether HFC-32, R-
454A, and R-454B should be listed as acceptable for chillers in IPR 
given their higher GWP than some other alternatives listed as 
acceptable, if they should not be listed in IPR at all, or if they 
should be listed as acceptable for all types of IPR equipment, and if 
so, why. Depending on public comments and information received, EPA may 
revise the substitutes listed with a use condition for use only in 
chillers for IPR or may not finalize some of the proposed listings.

F. Cold Storage Warehouses--Proposed 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

    EPA is proposing to list HFO-1234yf, HFO-1234ze(E), and the 
refrigerant blends R-454A, 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 proposed for cold storage warehouses are 
common to those proposed for the other end-uses in this rule. Because 
of this similarity, EPA discusses the use conditions that would apply 
to all five end-uses in section II.H. In summary, the common use 
conditions proposed include the following: restricting the use of each 
refrigerant to new equipment that is specifically designed for that 
refrigerant; use consistent with the 2nd edition of 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 following proposed use condition would also apply 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 proposed decisions appears in tables at 
the end of this document. If finalized as proposed, this text would be 
codified in appendix Y to 40 CFR part 82, subpart G. The proposed 
regulatory text contains listing decisions for the end-use discussed 
above. EPA notes that there may be other legal obligations pertaining 
to the manufacture, use, handling, and disposal of the proposed 
refrigerants that are not included in the information listed in the 
tables (e.g., the CAA section 608(c)(2) venting prohibition, or 
Department of Transportation 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 (R-717). 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 falls 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.''
    EPA is proposing to list HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, 
R-455A, R-457A, 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 proposed for cold 
storage warehouses in this section as being in the A2L Safety Group. 
See section II.A.2 for further discussion on ASHRAE classifications of 
these refrigerants.
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?
    See section II.A.3 for further discussion on the environmental, 
flammability, toxicity, and exposure information for HFO-1234yf, HFO-
1234ze(E), R-454A, R-454C, R-455A, R-457A, and R-516A.\58\
---------------------------------------------------------------------------

    \58\ EPA previously listed HFO-1234yf as acceptable, subject to 
use conditions, in motor vehicle AC in light-duty 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 HPs (86 FR 24444, May 6, 
2021).
---------------------------------------------------------------------------

    Redacted submissions and supporting documentation for HFO-1234yf, 
HFO-1234ze(E), and the refrigerant blends are provided in the docket 
for this proposed rule (EPA-HQ-OAR-2023-0043) at https://www.regulations.gov. EPA performed risk screening assessments to 
examine the health and environmental risks of each of these 
substitutes. These risk screens are available in the docket for this 
proposed rule.59 60 61 62 63 64 65
---------------------------------------------------------------------------

    \59\ ICF, 2023s. Op. cit.
    \60\ ICF, 2023t. Op. cit.
    \61\ ICF, 2023u. Op. cit.
    \62\ ICF, 2023w. Op. cit.
    \63\ ICF, 2023x. Op. cit.
    \64\ ICF, 2023y. Op. cit.
    \65\ ICF, 2023z. Op. cit.
---------------------------------------------------------------------------

    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) have GWPs less than four and less than 
six, respectively, comparable to that of (HCFO)-1233zd(E), 
CO2, and ammonia with GWPs of 3.7, one, and zero 
respectively. R-454A, 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, R-513A, 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/

[[Page 33745]]

substitutes-cold-storage-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 end-uses, are evaluated 
in the risk screens referenced above. 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 end-use. Toxicity risks of the 
proposed refrigerants can be minimized 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 HFO-1234yf, HFO-1234ze(E), R-454A, R-
454C, R-455A, R-457A, and R-516A in this end-use, determined by the 
likelihood of exceeding their respective lower flammability limits, are 
evaluated in the risk screens referenced above. 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 60335-2-89--which is required by our proposed use 
conditions--as well as recommendations in the manufacturers' SDS and 
other safety precautions common in the refrigeration and AC industry. 
EPA is proposing use conditions to reduce the potential risk associated 
with the flammability of these alternatives so that they will not pose 
significantly greater risk than other acceptable substitutes in this 
end-use.
    The proposed 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 substitutes 
for the full range of cold storage warehouses with lower GWP and, 
therefore, lower overall risk to human health and the environment, EPA 
is proposing the listings for 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 proposing to list 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 proposing these specific use conditions?
    The proposed use conditions identified in the proposed listings 
above are explained in section II.H.1.
    This proposal applies to end-uses covered by UL 60335-2-89, 
including the SNAP cold storage warehouses end-use. In addition, ASHRAE 
15-2022 applies to these refrigeration systems.
    The standard UL 60335-2-89 discussed in section II.H indicates that 
refrigerant charges greater than a specific amount (called 
``m3'' in the standard and based on the refrigerant's LFL) 
are beyond its scope and that national standards might apply, such as 
ASHRAE 15-2022. Hence, EPA is proposing to require adherence to both 
standards as use conditions for cold storage warehouses, broadening the 
coverage under this proposed rule.
    EPA is proposing to incorporate by reference ASHRAE 15-2022, 
including all addenda published by the date of this proposal, in use 
conditions that apply to use of the proposed A2L refrigerants in new 
cold storage warehouses. Where the requirements specified in this 
proposed rule (if finalized) and ASHRAE 15-2022 differ, the 
requirements of this rule would apply.
    EPA recognizes that ASHRAE 15-2022 is undergoing continuous 
maintenance with publication of periodic addenda and is typically 
updated and republished every three years. While this proposed rule 
incorporates all addenda to ASHRAE 15-2022 published by the date of 
this proposal, there may be additional changes by the time EPA issues a 
final rule based upon this proposal. However, given EPA would not have 
reviewed and proposed use conditions based on those changes, EPA is not 
proposing to include addenda or other changes made to ASHRAE 15-2022 
after the date of the proposed rule.
    EPA is proposing to list R-454A as acceptable, subject to use 
conditions, in cold storage warehouses with a use condition 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 proposing this use condition to allow 
use of R-454A less broadly than for the other refrigerants proposed for 
use in cold storage warehouses because its GWP is higher than those of 
the other proposed listings for this end-use (about 240, compared to 
less than four 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 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 200 pounds 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 
outdoors or in a machinery room with access restricted to employees. 
Where people are unlikely to come into contact with any leaked 
refrigerant, such as where charge sizes of 200 pounds or more of A2L 
refrigerant would be allowed under the use conditions incorporating UL 
60335-2-89 and ASHRAE 15-2022, there would be fewer space constraints 
and greater flexibility in equipment design, so refrigeration system 
designers can accommodate a narrower set of substitutes. Conversely, 
where people are more likely to come into contact with any leaked 
refrigerant in an interior space, refrigerant charge capacities of a 
system would be less than 200 pounds; there would be more space 
constraints, less flexibility in equipment design, and potentially 
stricter code requirements, leading to a need for more refrigerant 
options. Allowing the additional option of R-454A for cold storage 
warehouses with smaller refrigerant charges would enable the use of a 
wider set of available substitutes to manage safety (in particular, 
flammability and toxicity), as well as allowing more options to achieve 
adequate performance where there may be more constraints. Therefore, 
EPA is proposing to list R-454A as acceptable, subject to use 
conditions, only for cold storage warehouses with a refrigerant charge 
capacity less than 200 pounds.
    EPA is also proposing to list R-454A as acceptable, subject to use 
conditions, for use in the high temperature side of cascade systems 
used for cold storage

[[Page 33746]]

warehouses. As discussed above in section II.A.1, ``Background on 
retail food refrigeration,'' each system 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, low boiling refrigerants 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 standards). EPA notes that there are a number of 
substitutes available for the low temperature side of the cascade 
system with GWPs lower than that of R-454A. Therefore, instead of 
proposing to list R-454A as acceptable, subject to narrowed use limits 
and subject to use conditions, EPA is proposing to list 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.
5. What additional information is EPA including in these proposed 
listings?
    EPA is providing additional information related to these proposed 
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. See section II.H.2 for 
further discussion on what additional information EPA is including in 
these proposed listings. 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.
6. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed decision 
to list HFO-1234yf, HFO-1234ze(E), R-454A, R-454C, R-455A, R-457A, and 
R-516A acceptable, subject to use conditions, in new cold storage 
warehouses as discussed in this section II.F. EPA seeks comment on the 
risk mitigation offered by the proposed use conditions, including 
requiring compliance with the 2nd edition of UL 60335-2-89 under the 
SNAP program, except to the extent the proposed rule conflicts with the 
UL Standard, in which case we propose that the use conditions specified 
in the rule would apply. The Agency takes comment on our proposal to 
limit R-454A to use either in equipment with a refrigerant charge 
capacity less than 200 pounds or in the high temperature side of a 
cascade system. We also request comment on whether EPA should consider 
other use conditions to further mitigate potential risk from 
refrigerants. EPA requests comment on whether cold storage warehouses 
have been designed for or manufactured with the refrigerants proposed 
and any information on the safety of such equipment in other countries, 
and if and how such experience would translate to safe use in the 
United States.

G. Ice Skating Rinks--Proposed 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

    EPA is proposing to list 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.
    Several use conditions proposed for ice skating rinks with a remote 
compressor are common to those proposed for other end-uses. Because of 
this similarity, EPA discusses the use conditions that would apply to 
all five end-uses in section II.H. For ice skating rinks with remote 
compressors, those are the only use conditions EPA is proposing. In 
summary, the common use conditions proposed include the following: 
restricting the use of each refrigerant to new equipment that is 
specifically designed for that refrigerant; use consistent with the 2nd 
edition of 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 proposed decisions appears in tables at 
the end of this document. If finalized as proposed, this text would be 
codified in appendix Y to 40 CFR part 82, subpart G. EPA notes that 
there may be other legal obligations pertaining to the manufacture, 
use, handling, and disposal of the proposed 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, are used by 
the general public for recreational purposes and also include 
professional rinks. 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 proposed listings would apply only to ice skating rinks 
that have a remote compressor.
    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 (R-717). 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). This type of equipment falls under the scope of 
UL 60335-2-89, ``Requirements for Commercial Refrigerating Appliances 
and Ice-Makers with an Incorporated or

[[Page 33747]]

Remote Refrigerant Unit or Motor-Compressor.''
2. What are the ASHRAE classifications for refrigerant flammability?
    ASHRAE Standard 34-2022 categorizes the refrigerants proposed for 
ice skating rinks in this section as being in the A2L Safety Group. See 
section II.A.2 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 for further discussion on the environmental, 
flammability, toxicity, and exposure information for these 
refrigerants.\66\
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    \66\ EPA previously listed HFO-1234yf as acceptable, subject to 
use conditions, in motor vehicle AC in light-duty 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-454C, and R-457A as 
acceptable, subject to use conditions, as substitutes in residential 
and light commercial AC and HPs (86 FR 24444, May 6, 2021).
---------------------------------------------------------------------------

    Redacted submissions and supporting documentation for HFO-1234yf, 
HFO-1234ze(E) and the blends R-454C, R-455A, R-457A and R-516A are 
provided in the docket for this proposed 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 
substitutes. These risk screens are available in the docket for this 
proposed rule.67 68 69 70 71 72
---------------------------------------------------------------------------

    \67\ ICF, 2023s. Op. cit.
    \68\ ICF, 2023t. Op. cit.
    \69\ ICF, 2023w. Op. cit.
    \70\ ICF, 2023x. Op. cit.
    \71\ ICF, 2023y. Op. cit.
    \72\ ICF, 2023z. Op. cit.
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: HFO-1234yf, HFO-
1234ze(E) and 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) have GWPs of less than four and less 
than six, respectively, 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 acceptable substitutes for new ice skating rinks, such 
as R-450A, 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-skating-rinks). 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 end-
uses, are evaluated in the risk screens referenced above. The toxicity 
risks of using HFO-1234yf, HFO-1234ze(E), and 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 proposed refrigerants can be 
minimized by use consistent with ASHRAE 15-2022--which would be 
required by our proposed 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, R-455A, R-457A, and R-516A in this end-use, determined by the 
likelihood of exceeding their respective lower flammability limits, are 
evaluated in the risk screens referenced above. 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 proposed use conditions--as 
well as recommendations in the manufacturers' SDS and other safety 
precautions common in the refrigeration and AC industry. EPA is 
proposing use conditions to reduce the potential risk associated with 
the flammability of these alternatives so that they will not pose 
significantly greater risk than other acceptable substitutes in this 
end-use. In addition, EPA is proposing to limit these listings to 
equipment with a remote compressor. Such equipment reduces the chances 
of exposure to the general public compared to refrigerants that are 
piped directly under an ice skating rink. This also can reduce the 
amount of refrigerant used, potentially reducing climate impacts of any 
refrigerant released.
    In addition, the proposed substitutes have lower GWPs than most 
other available alternatives for the same end-use. The proposed 
refrigerants may provide additional lower-GWP 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 substitutes with lower 
GWP for more ice skating rinks and, therefore, lower overall risk to 
human health and the environment, EPA is proposing the listings for 
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.
4. Why is EPA proposing these specific use conditions?
    The use conditions identified in the proposed listings above are 
explained in section II.H.1.
    This proposal applies to end-uses covered by UL 60335-2-89, 
including the SNAP ice skating rinks end-use. In addition, ASHRAE 15-
2022 applies to these refrigeration systems.
    The standard UL 60335-2-89 discussed in section II.H indicates that 
refrigerant charges greater than a specific amount (called 
``m3'' in the standard and based on the refrigerant's LFL) 
are beyond its scope and that national standards might apply, such as 
ASHRAE 15-2022. Hence, EPA is proposing to require adherence to both 
standards as use conditions for ice skating rinks, broadening the 
coverage under this proposed rule.
    EPA is proposing to incorporate by reference ASHRAE 15-2022, 
including all addenda published by the date of this proposal, in use 
conditions that apply to use of the proposed A2L refrigerants in new 
ice skating rinks. Where the requirements specified in this proposed 
rule (if finalized) and ASHRAE 15-2022 differ, the requirements of this 
rule would apply.
    EPA recognizes that ASHRAE 15-2022 is undergoing continuous 
maintenance with publication of periodic addenda and is typically 
updated and republished every three years. While this proposed rule 
incorporates all addenda to ASHRAE 15-2022 published by the date of 
this proposal, there may be additional changes by the time EPA issues a 
final rule based upon this proposal. However, given EPA would not have 
reviewed

[[Page 33748]]

and proposed use conditions based on those changes, EPA is not 
proposing to include addenda or other changes made to ASHRAE 15-2022 
after the date of the proposed rule.
    EPA is proposing a use condition that the six A2L refrigerants may 
only be used in new equipment that includes a remote compressor. This 
is intended to ensure that these flammable refrigerants, which are 
likely to use large charge sizes, are only used in situations where the 
refrigerant is removed 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 proposed 
listings?
    EPA is providing additional information related to these proposed 
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. See section II.H.2 for 
further discussion on what additional information EPA is including in 
these proposed listings. 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.
6. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of this proposed decision 
to list HFO-1234yf, HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A 
as acceptable, subject to use conditions, in new ice skating rinks with 
a remote compressor as discussed in this section II.G. We request 
comment on our initial evaluation and our proposal to find HFO-1234yf, 
HFO-1234ze(E), R-454C, R-455A, R-457A, and R-516A acceptable, subject 
to use conditions, for use in new ice skating rinks. EPA seeks comment 
on the risk mitigation offered by the proposed use conditions, 
including requiring compliance with the 2nd edition of UL 60335-2-89, 
except to the extent the proposed rule conflicts with the UL Standard, 
in which case we propose that the use conditions specified in the rule 
would apply. We also request comment on whether EPA should consider 
other use conditions to further mitigate potential risk from 
refrigerants. EPA requests comment on whether equipment for such ice 
skating rinks with remote compressors in the United States has already 
been designed or manufactured for the refrigerants proposed and any 
information on the safety of such equipment in other countries, and if 
and how such experience would translate to safe use in the United 
States. The Agency also requests comment on whether these listings 
should be restricted to ice skating rinks with a remote compressor, if 
they should be allowed for any ice skating rink, or if they should be 
limited to a different subset of ice skating rinks (e.g., for use only 
in the primary loop of a secondary loop systems).

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 proposing and why?
    As described above, EPA is proposing to list:
     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, 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 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, for use in new chillers for IPR;
     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 proposing to update 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 self-contained commercial ice machines.
    These use conditions are summarized in the listings under preamble 
units II.A, II.C, II.E, II.F, and II.G, and the revisions to the use 
conditions are summarized under preamble units II.B and II.D and are 
explained here in greater detail. The proposed use conditions (either 
as new listings or revisions to an existing listing) include 
restricting the use of each refrigerant to new equipment that is 
specifically designed for the refrigerant; use consistent with the 2nd 
edition of 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 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 proposing that these refrigerants may be used only in new 
equipment which has been designed to address concerns unique to 
flammable refrigerants--i.e., none of these substitutes may 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 for this proposal and is only proposing 
that they may be used in new equipment which can be properly designed 
for their use. This proposed use condition would 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 proposed flammable refrigerants, EPA is

[[Page 33749]]

proposing to incorporate by reference certain industry consensus safety 
standards in a use condition. Specifically, the Agency is proposing 
that the flammable refrigerants may be used only in equipment that 
meets all requirements in the 2nd edition of UL 60335-2-89.
    Currently, new stand-alone units using R-290 are subject to a use 
condition to meet the requirements of Appendix SB of the 10th edition 
of the standard UL 471. If this rule becomes final as proposed, stand-
alone units using R-290 manufactured before the effective date could 
continue to be used under SNAP and would remain in compliance with the 
SNAP use conditions as long as they met the applicable use conditions 
when they were manufactured. EPA is proposing that new stand-alone 
units using R-290 manufactured from the effective date of the final 
rule through September 29, 2024, must meet the requirements of either 
Appendix SB of the 10th edition of UL 471 or the 2nd edition of UL 
60335-2-89. The Agency is also proposing that new stand-alone units 
using R-290 that are manufactured on or after September 30, 2024, must 
meet the requirements of the 2nd edition of UL 60335-2-89, rather than 
the earlier UL standards.
    Currently, new self-contained commercial ice machines using R-290 
must meet the requirements of Appendix SA of the 8th edition of UL 563. 
If this rule becomes final as proposed, commercial ice machines using 
R-290 manufactured before the effective date of a final rule could 
continue to be used under SNAP and would remain in compliance with the 
SNAP use conditions as long as they met the applicable use conditions 
when they were manufactured. EPA is proposing that new self-contained 
commercial ice machines using R-290 that are manufactured from the 
effective date of the final rule through September 29, 2024, must meet 
the requirements of either Appendix SA of the 8th edition of UL 563 or 
the 2nd edition of UL 60335-2-89. The Agency is also proposing that new 
self-contained commercial ice machines using R-290 that are 
manufactured on or after September 30, 2024, must meet the requirements 
of the 2nd edition of UL 60335-2-89, rather than the earlier UL 
standards.
    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 in 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 proposing to rely 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 UL 60335-2-89 as they affect the 
proposed refrigerants and end-uses is offered here for information only 
and does not provide a complete review of the requirements in this 
standard.
    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. Annex DVU provides guidance on how to apply the 
requirements to allow for safe use of A2L refrigerants. The 2nd edition 
of 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); mitigation means 
(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 (i.e., 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 15-2022. Specifically, if the refrigeration 
circuit with the greatest mass of an A2L refrigerant is more than 260 
times the lower flammability limit (in kg/m\3\), such equipment is 
outside the scope. For example, HFC-32 has an LFL of approximately 
0.307 kg/m\3\ (0.0192 lb/ft\3\); therefore, equipment with charge sizes 
of a single circuit exceeding 79.82 kg (176.0 lb) would fall outside 
the scope of UL 60335-2-89. In such situations, the refrigerant 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 (500 g of R-290) for equipment that is open 
and contains no doors or drawers and eight times the LFL (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 proposing that an additional safety standard, ASHRAE 
15-2022, apply to commercial refrigeration equipment using A2L 
refrigerants, as discussed in section II.A. Certain key provisions of 
ASHRAE 15-2022 are described above in section II.A; that standard 
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, e.g., for use in 
refrigeration

[[Page 33750]]

systems with large charge sizes in a machinery room or outdoors.
Warning Labels--Equipment With A2L Refrigerants
    As a use condition or revision to existing use conditions, EPA is 
proposing to require 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 proposed lower flammability (A2L) refrigerants. The text 
of these labels can also be found in Annex 101.DVV of UL 60335-2-89. 
EPA is proposing that the following labels, or the equivalent, must be 
provided in letters no less than 6.4 mm (\1/4\ 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''
    1. If the equipment is delivered packaged, this label shall be 
applied on the packaging
    2. 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 1 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 1 or 2, 
respectively.
    5. On indoor unit near the nameplate:
    1. 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 the 2nd edition of 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.
    2. Immediately below 5.1. above or at the top of the marking if 
5.1. is not required: ``Minimum room area (operating or storage), Y 
m\2\ (Z ft\2\)''. 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 Inch-Pound 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. above 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 only 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 proposing 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 proposing to require the minimum height for lettering must be 
\1/4\ inch as opposed to \1/8\ inch. This would 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 proposed use condition for refrigerated food processing and 
dispensing equipment and a proposed revision to existing use conditions 
for stand-alone units and commercial ice machines, EPA is proposing to 
require 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. EPA is 
proposing that the following markings, or the equivalent, must be 
provided in letters no less than 6.4 mm (\1/4\ 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''.
    1. If the equipment is delivered packaged, this label shall be 
applied on the packaging.
    2. 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 1 above. EPA expects that other types 
of commercial refrigeration equipment

[[Page 33751]]

could be provided packaged or not, and this label would be placed as 
stipulated in item 1 or 2, respectively.
    5. On indoor unit near the nameplate:
    1. 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 the 2nd edition of 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.
    2. Immediately below 5.1. above or at the top of the marking if 
5.1. is not required: ``Minimum room area (operating or storage), Y 
m\2\ (Z ft\2\)''. 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.
    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, above, is exactly the same as that 
required in UL 60335-2-89, with the exception of the label identified 
in 5., which is similar to 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 proposing in this action. As in the requirements in our 
previous rules for A3 refrigerants (i.e., 76 FR 78832, December 20, 
2011; 80 FR 19454, April 10, 2015; and 81 FR 86778, December 1, 2016), 
EPA is proposing that the minimum height for lettering be \1/4\ inch, 
which would make it easier for technicians, consumers, retail 
storeowners, first responders, and those disposing the appliance to 
view the warning labels.
Markings
    EPA is proposing to require as a use condition that the 
refrigerants must be used in refrigerating equipment that has red, 
Pantone[supreg] 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 proposed are required by UL 60335-2-89 for all flammable 
refrigerants. EPA is proposing that such markings apply to the proposed 
listings for flammable refrigerants as well to establish a common, 
familiar, and standard means of identifying the use of a flammable 
refrigerant.
    These red markings would help technicians immediately identify the 
use of a flammable refrigerant, thereby reducing the risk of using 
sparking equipment or otherwise having an ignition source nearby. 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. 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 
electric vehicles. Currently in SNAP listings, color-coded hoses or 
pipes must be used for ethane, HFC-32, R-452B, R-454A, R-454B, R-454C, 
R-457A, R-600a, R-290, and R-441A in certain types of equipment where 
these are listed acceptable, subject to use conditions. All such tubing 
must be colored red PMS #185 or RAL 3020. The intent of this aspect of 
the proposal is to alert technicians and others that a flammable 
refrigerant is being used within a particular piece of equipment or 
appliance. Another goal is to provide adequate notification of the 
presence of flammable refrigerants for personnel disposing of 
appliances containing flammable refrigerants. 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 could be used. The 
colored plastic sleeve, cap, or tape would have to be forcibly removed 
to access the service tube and would have to be replaced if removed. 
This would signal to the technician that the refrigeration circuit that 
she/he was about to access contained a flammable refrigerant, even if 
all warning labels were somehow 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 proposing the use of color-coded hoses or piping as a way 
for technicians and others to recognize that a flammable refrigerant is 
used in the equipment. This would be in addition to the proposed use of 
warning labels discussed above. EPA believes having two such 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 also is proposing to add a new marking to 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 refrigeration equipment that is charged in place. 
These locations correspond with the locations for red markings and for 
the 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. UL 60335-2-89 describes markings in section 7, including 
a triangular symbol with a white picture of a flame on a red 
background, similar in size and shape to that of the International 
Organisation for Standardisation (ISO) symbol 7000-W021, but with 
different coloration (Clause 7.6DV D1). EPA is proposing a new 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. The diamond 
symbol hazard category 1 flammable gases would need to be at least 15 
mm (9/16 inches) high.
    EPA understands that in consultation with different fire service 
groups, such as the International Association of Fire

[[Page 33752]]

Fighters, UL and its standard-setting committees have been considering 
appropriate symbols to alert first responders to the presence and 
potential hazards of flammable refrigerant. One symbol under 
consideration is an equal-sided diamond with a red outline and a flame 
symbol on a white background, together with the refrigerant class from 
ASHRAE 34-2022 (e.g., A2L or A3) to be written in text not less than 
one-third of the height of the 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.\73\ 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. You 
may see the proposed symbol for hazard category 1 flammable gases in 
the docket for this rulemaking under the title, ``Proposed Flammability 
Hazard Symbol.''
---------------------------------------------------------------------------

    \73\ GHS, 2021. GHS 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. You may 
find the GHS document online at https://unece.org/sites/default/files/2021-9/GHS_Rev9E_0.pdf or from the United Nations Publications 
section at: https://shop.un.org/books/global-harmon-syst-class-9-92280.
---------------------------------------------------------------------------

    EPA is proposing to add this symbol to ensure the adoption of a 
symbol for ``Caution, risk of fire'' that is likely to be recognized by 
first responders in the United States as well as internationally. The 
symbol ISO 7000-W021, used in other UL standards for refrigerating 
equipment, is a black flame symbol on a yellow triangle. U.S. 
organizations representing fire fighters have raised concerns about 
that symbol, since it could refer 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. EPA is proposing to include the GHS diamond symbol for 
hazard category 1 flammable gases prior to UL's adoption of it in UL 
60335-2-89 to provide an additional warning about flammability hazard 
that is more likely to be recognizable by first responders and 
internationally than the current symbol in UL 60335-2-89.
2. What additional information is EPA including in these proposed 
listings?
    For retail food refrigeration, commercial ice machines, IPR, cold 
storage warehouses, and ice skating rinks with remote compressors, EPA 
is proposing to include recommendations, found in the ``Further 
Information'' column of the regulatory text at the end of this 
document, to protect personnel from the risks of using flammable 
refrigerants. Similar to our previous listings of flammable 
refrigerants, EPA is proposing to include 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 
substitutes.
3. On which topics is EPA specifically requesting comment?
    EPA is requesting comment on all aspects of the proposed use 
conditions described above and the appropriateness for applying these 
use conditions to the listings for A2L refrigerants used in retail food 
refrigeration, commercial ice machines, IPR and chillers for IPR, cold 
storage warehouses, and ice skating rinks with remote compressors in 
sections II.A, II.C, II.E, II.F, and II.G, respectively.
    EPA is requesting comment on all aspects of the proposed use 
conditions described above and the appropriateness for applying these 
use conditions to the listing for R-290 used in refrigerated food 
processing and the proposed revisions to the use conditions in existing 
listings for R-290 in stand-alone units and self-contained commercial 
ice machines in sections II.B and II.D.
    EPA is requesting comment on the applicability of UL 60335-2-89 to 
commercial refrigeration equipment, including for which types of 
equipment and under which applications the standard applies. We 
likewise are requesting comment on the applicability of UL 60335-2-89 
to commercial ice machines, IPR equipment, cold storage warehouses, and 
ice skating rinks with remote compressors.
    Also, with regard to UL 60335-2-89, EPA is requesting comment on 
the status of the standard, the modifications that are being or have 
been incorporated in it, how those modifications would change the risk 
associated with the use of the proposed flammable refrigerants in these 
end-uses, and the appropriateness of adopting as a use condition the 
current (2nd) edition of this standard.
    EPA is also requesting comment on requiring labeling, the height of 
the lettering, the proposed diamond symbol for hazard category 1 
flammable gases, and the likelihood of labels remaining on a product 
throughout the lifecycle of the product, including its disposal.

I. Proposed Exemption for R-290 From the Venting Prohibition Under CAA 
Section 608 for Refrigerated Food Processing and Dispensing Equipment.

1. What is EPA's proposed determination regarding whether venting, 
releasing, or disposing of R-290 in refrigerated food processing and 
dispensing equipment would pose a threat to the environment?
    As described in section I.A above, 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 industrial 
process refrigeration, 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 industrial 
process refrigeration) 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 above, EPA is 
proposing to list 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 
proposing to exempt R-290 in this end-use from the venting prohibition 
under CAA section 608(c)(2), on the basis of current evidence that the 
venting, release, or disposal of this substance in this end-use and 
subject to the use conditions in this proposed action does not pose a 
threat to the environment.
    For purposes of CAA section 608(c)(2), EPA considers two factors in 
determining whether or not venting, release, or disposal of a 
refrigerant substitute during the maintenance, servicing, repairing, or 
disposing of appliances poses a threat to the environment. See 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

[[Page 33753]]

refrigerant substitute, such as GWP or photochemical reactivity. 
Second, EPA determines whether and to what extent 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 
R-290 into the environment, a substitute that we are proposing to list 
under the SNAP program 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 sizes 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 (see 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 the compound 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 if 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. Based on the analysis and modeling 
results described in section II.B.3, EPA proposes to conclude that the 
release of R-290 from the refrigerated food processing and dispensing 
end-use, in addition to the HCs previously 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 NAAQS at 70 ppb.\74\
---------------------------------------------------------------------------

    \74\ ICF, 2016. Additional Follow-on Assessment of the Potential 
Impact of Hydrocarbon Refrigerants on Ground Level Ozone 
Concentrations. September, 2016.
---------------------------------------------------------------------------

    In addition, when examining all HC substitute refrigerants in those 
uses for which UL currently has standards in place, for which the SNAP 
program has already listed the uses as acceptable, subject to use 
conditions, or for which the SNAP program is reviewing a submission, 
including those in this proposed action, we found that even if all the 
HC refrigerant substitutes in appliances in end-uses proposed to be 
listed acceptable, subject to use conditions, in this action and listed 
as acceptable in previous rules were to be emitted, there would be a 
worst-case impact of less than 0.15 ppb for ground-level ozone in the 
Los Angeles area.\75\ 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 end-use. Because R-290 is not listed as 
acceptable for use in all refrigerant uses, the total amount of R-290 
that could be emitted in the end-uses evaluated is estimated at roughly 
ten percent of total refrigerant emissions, or less than 16,000 metric 
tons annually.\76\ In comparison, total anthropogenic VOC emissions 
were estimated at 19.6 million metric tons in 2017.\77\ Further, there 
are other substitute refrigerants that are not VOC that may also be 
used in these end-uses, so our analysis assuming complete market 
penetration of HCs is conservative.
---------------------------------------------------------------------------

    \75\ ICF, 2014a. Assessment of the Potential Impact of 
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. 
February 2014.
    \76\ Ibid.
    \77\ U.S. EPA, 2020. 2017 National Emissions Inventory Report. 
U.S. Environmental Protection Agency. Available online at https://gispub.epa.gov/neireport/2017/.
---------------------------------------------------------------------------

    EPA also has performed more recent air quality analysis, 
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.\78\ 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, 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 2020 analysis compared to 7.8 ppb in Los Angeles 
in an analysis in 2016 looking at the same scenario with the same 
refrigerant. 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 0.01 ppb in Houston and Atlanta.\79\ Looking at the 2020 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 ground-level ozone in 
Los Angeles was 0.012 ppb, in Houston was 0.009 ppb, and in Atlanta was 
0.006 ppb. Unlike the 2016 analysis, the 2020 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). The modeled changes to ground-level 
ozone levels were less than 0.017 percent of the NAAQS 8-hour ozone 
concentration of 70 ppb.\80\ EPA considers this 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.
---------------------------------------------------------------------------

    \78\ ICF, 2020. 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, 2020.
    \79\ ICF, 2016. Additional Follow-on Assessment of the Potential 
Impact of Hydrocarbon Refrigerants on Ground Level Ozone 
Concentrations. September 2016.
    \80\ ICF, 2020. Op cit.

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[[Page 33754]]

    Considering our evaluation of these potential environmental 
impacts, EPA proposes to conclude 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
    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, 2016, and 2022 (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. As explained below, EPA proposes 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.
    As mentioned above, 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 
disposal is adequately controlled by other authorities, regulations, or 
practices. This information is another part of EPA's proposal that the 
venting, release, or disposal of R-290, in the specified end-use and 
subject to the use conditions in this proposed action, does not pose a 
threat to the environment.
    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 proposing?'' and 
II.D.5, ``What updates to existing use conditions for commercial ice 
machines is EPA proposing?'' above in this document, we note that the 
amount of substitute refrigerant from a refrigerant loop is effectively 
limited to 500 g or 300 g in the end-uses proposed in this rule. This 
indicates that HC emissions from such uses are likely to be relatively 
small.
    As discussed above 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 R-290 in the 
proposed new end-use in this 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 proposal provides recommendations for its safe use (see 
section II.H.2, ``What additional information is EPA including in these 
proposed listings?''). The SNAP program's analysis suggests that the 
proposed 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 
proposed use conditions in this rule would 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 proposing to incorporate 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 15-2022 are in the process of being adopted in 
the next version of the IBC; once the IBC adopts those standards, 
states 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 proposal regarding whether venting of R-290 from 
refrigerated food processing and dispensing equipment should be 
exempted from the venting prohibition under CAA section 608(c)(2)?
    Consistent with the proposed listing under SNAP in this action, EPA 
proposes to determine 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 more fully above, 
we propose this on the basis of the inherent characteristics of this 
substance, the limited quantities used in the relevant end-uses, 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 
proposing to revise the regulations at Sec.  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 would the exemption from the venting prohibition apply?
    We are proposing that this exemption for R-290 in refrigerated food 
processing and dispensing equipment would apply as of 30 days after the 
publication of a final rule in the Federal Register. This would be the 
same as the proposed effective date of the SNAP listing of R-290 in 
refrigerated food processing and dispensing equipment, if that listing 
is finalized as proposed.

[[Page 33755]]

4. What is the relationship between this proposed exemption under CAA 
section 608(c)(2) and other EPA rules?
    If this proposed exemption were to become final as proposed, it 
would not mean that R-290 could be vented in all situations. R-290 and 
other HCs being recovered, vented, released, or otherwise disposed of 
from commercial and industrial appliances are 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), R-600a, 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. On which topics is EPA specifically requesting comment?
    EPA requests comment on all aspects of our proposal to exempt R-290 
used as a refrigerant substitute in refrigerated food processing and 
dispensing equipment from the venting prohibition under CAA section 
608(c)(2), as well as seeking comment on the proposed addition to the 
existing exemption language for R-290 in particular end-uses at 40 CFR 
82.154(a)(1)(viii). The Agency notes that the proposed regulatory text 
contains the proposed addition to Sec.  82.154(a)(1)(viii), as well as 
certain other exemptions for other end-uses that already appear at 40 
CFR 82.154(a)(1)(viii) and that EPA is republishing for purposes of 
formatting for the Federal Register. EPA is not proposing changes to, 
and is not taking comment on, those existing exemptions and we are not 
reopening for comment those current exemptions for the other end-uses 
where R-290 may be used.

III. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review.

    This action is not a significant regulatory action 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 proposed 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 proposed 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 proposes to add the additional options under SNAP of 
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, R-454B, 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 
proposed 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 standard; these would 
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 a final rule 
based on this proposal would 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 
would result in no adverse impact compared with the absence of this 
proposed rule. Thus, if the rule were finalized as proposed, it would 
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 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.

[[Page 33756]]

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 economically 
significant as defined in 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 proposed rule, the rule does contain use 
conditions that would 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 proposed 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 1 CFR Part 51

    This action involves technical standards. EPA uses and proposes to 
incorporate by reference portions of the 2021 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.
    The 2021 standard UL 60335-2-89, ``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=UL60335-2-89_2_S_20211027, and may be 
purchased by mail at: COMM 2000, 151 Eastern Avenue, Bensenville, IL 
60106; Email: [email protected]; Telephone: 1-888-853-3503 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 proposed to be incorporated by reference is reasonably 
available.
    EPA is also proposing to incorporate by reference the GHS diamond 
symbol (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, copyrighted in 2021, in the use conditions 
for hazard labeling of commercial and industrial refrigeration 
equipment. This document is available for viewing online at: https://unece.org/sites/default/files/2021-9/GHS_Rev9E_0.pdf. 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. 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 GHS symbol proposed to be 
incorporated by reference is reasonably available.
    EPA is also proposing to incorporate by reference ANSI/ASHRAE 
Standard 15-2022, ``Safety Standard for Refrigeration Systems,'' 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,'' 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/technical-resources/bookstore/ashrae-refrigeration-resources, and may be purchased by mail at: 180 
Technology Parkway NW, Peachtree Corners, Georgia 30092; by telephone: 
1-800-527-4723 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 these standards 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 proposed to be incorporated by reference are 
reasonably available.
    The following standards are already approved for locations where 
they appear in the amendatory text: UL 471, UL 541, UL 484, UL 60335-2-
24, and 60335-2-40.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) directs 
Federal agencies, to the greatest extent practicable and permitted by 
law, to make environmental justice part of their mission by identifying 
and addressing, as appropriate, disproportionately high and adverse 
human health or environmental effects of their programs, policies, and 
activities on minority populations (people of color and/or indigenous 
peoples) and low-income populations.
    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 
people of color, low-income populations and/or indigenous peoples. This 
action's health and environmental risk assessments are contained in the 
comparison of health and environmental risks for HFC-32, HFO-1234yf, 
HFO-1234ze(E), R-290, R-454A, R-454B, 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. EPA's analysis indicates that other environmental 
impacts and human health impacts of HFC-32, HFO-1234yf, HFO-1234ze(E), 
R-290, R-454A, R-454B, R-454C, R-455A, R-457A, and R-516A are 
comparable to or less than those of other substitutes that are listed 
as acceptable for the same end-use. Because adoption of the new 
substitutes listed in this proposed rule is voluntary, the Agency is 
unable to quantify when, where, and

[[Page 33757]]

how much of the listed substitutes will be produced and used. Thus, EPA 
cannot determine the extent to which this proposed 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).
    EPA believes that it is not practicable to assess whether this 
action is likely to result in new disproportionate and adverse effects 
on people of color, low-income populations, and/or indigenous peoples. 
The Agency will continue to evaluate the impacts of this program on 
communities with environmental justice concerns and consider further 
action, as appropriate.

IV. References

    Unless specified otherwise, all documents are available 
electronically through the Federal Docket Management System 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.
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.
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 at 
https://unece.org/sites/default/files/2021-9/GHS_Rev9E_0.pdf or from 
the United Nations Publications section at: https://shop.un.org/books/global-harmon-syst-class-9-92280.
Hodnebrog, et al., 2013. Hodnebrog, [Oslash]., 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, 2020. Additional Assessment of the Potential Impact of 
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. May, 
2020.
ICF, 2023a. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: HFO-1234yf.
ICF, 2023b. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: HFO-1234ze(E) (Solstice[supreg] ze, 
Solstice[supreg] 1234ze).
ICF, 2023c. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: R-454A (Opteon[supreg] XL40).
ICF, 2023d. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: R-454C (OpteonTM XL20).
ICF, 2023e. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: R-455A (Solstice[supreg] L40X).
ICF, 2023f. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: R-457A (Forane[supreg] 457A).
ICF, 2023g. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: R-516A (Forane[supreg] 516A).
ICF, 2023h. Risk Screen on Substitutes in Retail Food Refrigeration 
(New Equipment); Substitute: Propane (R-290).
ICF, 2023i. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: HFC-32.
ICF, 2023j. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: HFO-1234yf.
ICF, 2023k. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-454A (Opteon[supreg] XL40).
ICF, 2023l. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-454B (Opteon[supreg] XL41).
ICF, 2023m. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-454C (OpteonTM XL20).
ICF, 2023n. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-455A (Solstice[supreg] L40X).
ICF, 2023o. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-457A (Forane[supreg] 457A).
ICF, 2023p. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: R-516A (Forane[supreg] 516A).
ICF, 2023q. Risk Screen on Substitutes in Commercial Ice Machines 
(New Equipment); Substitute: Propane (R-290).
ICF, 2023r. Risk Screen on Substitutes in Industrial Process 
Refrigeration (New Equipment); Substitute: HFC-32 (Difluoromethane)
ICF, 2023s. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: HFO-1234yf.
ICF, 2023t. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: HFO-1234ze(E) (Solstice[supreg] ze, 
Solstice[supreg] 1234ze).
ICF, 2023u. Risk Screen on Substitutes in Industrial Process 
Refrigeration and Cold Storage Warehouses (New Equipment); 
Substitute: R-454A (Opteon[supreg] XL40).
ICF, 2023v. Risk Screen on Substitutes in Industrial Process 
Refrigeration (New Equipment); Substitute: R-454B (Opteon[supreg] 
XL41).
ICF, 2023w. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: R-454C (OpteonTM XL20).
ICF, 2023x. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: R-455A (Solstice[supreg] L40X).
ICF, 2023y. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: R-457A (Forane[supreg] 457A).
ICF, 2023z. Risk Screen on Substitutes in Industrial Process 
Refrigeration, Cold Storage Warehouses, and Ice Skating Rinks (New 
Equipment); Substitute: R-516A (Forane[supreg] 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=CH2.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 Ice-Makers 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 (WMO), 2018. Burkholder et al. 
Appendix A, Table A-1 in Scientific Assessment of

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Ozone Depletion: 2018, Global Ozone Research and Monitoring Project, 
Report No. 58, World Meteorological Organization, Geneva, 
Switzerland. Available at: https://ozone.unep.org/science/assessment/sap.

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 set forth in the preamble, EPA proposes to amend 40 
CFR part 82 as follows:

PART 82--PROTECTION OF STRATOSPHERIC OZONE

0
1. The authority citation for part 82 continues to read as follows:

    Authority: 42 U.S.C. 7414, 7601, 7671-7671q.

Subpart G--Significant New Alternatives Policy Program

0
2. Amend appendix R to subpart G of part 82 by:
0
a. Revising the heading; and
0
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 [date of publication of the final rule], Final Rule, Effective 
[effective date of the final rule]

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0
3. Amend appendix V to subpart G of part 82 by:
0
a. Revising the heading; and
0
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 [date of 
publication of the final rule], Final Rule, Effective [effective date 
of final rule]

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0
4. 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 [Date of 
publication of the final rule in the Federal Register], Final Rule, 
Effective [30 days after date of publication of the final rule in the 
Federal Register]

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0
5. Amend Sec. 82.154 by revising paragraph (a)(1)(viii) to read as 
follows:

Sec. 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; self-contained room air conditioners for 
residential and light commercial air-conditioning and heat pumps; 
vending machines; effective January 3, 2017, self-contained commercial 
ice machines, very low temperature refrigeration equipment, and water 
coolers; and effective [30 DAYS AFTER PUBLICATION OF FINAL RULE IN THE 
FEDERAL REGISTER], retail food refrigeration--refrigerated food 
processing and dispensing equipment;
* * * * *
[FR Doc. 2023-09600 Filed 5-23-23; 8:45 am]
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