Concerning one commenter's request for either an exception or a
longer period to comply for refrigerated laboratory equipment, to the
extent that equipment used in the laboratory has exiting fluid
temperatures of -50 [deg]C (-58 [deg]F) or lower, EPA notes that this
equipment will also not be restricted from using HFCs or HFC blends
under this final rule. Refrigerated laboratory equipment operating at
temperatures at or above -50 [deg]C (-58 [deg]F) and less than -30
[deg]C (-22 [deg]F) is considered part of IPR, and will have three
years longer than proposed, until 2028, for new equipment to transition
to substitute

refrigerants. Laboratory refrigerated equipment that operates at
temperatures higher than -30 [deg]C (-22 [deg]F), also part of IPR, is
similar to retail food refrigerators and freezers with alternatives
that are already available (e.g., R-290), and under this final rule,
they will have one year longer than proposed, until 2026.
b. Data Center, Information Technology Equipment Facility, and Computer
Room Cooling Equipment
    In the proposed rule, EPA indicated that appliances used to cool
data centers and data servers were considered part of the IPR
subsector. After review of the comments and relevant industry standards
in consideration of the subsection (i)(4) factors of the AIM Act, EPA
is creating a new subsector for data center, ITEF, and computer room
cooling equipment, subject to a 700 GWP limit beginning January 1,
2027. Such cooling equipment is designed specifically for large-scale
cooling or AC of information technology (IT). Examples include server
farms, ITEFs, computer rooms, data centers, data servers, communication
rooms, and other spaces dedicated to maintaining the operating
temperature of electronic technologies. Equipment typically has large
refrigerant charge capacities to satisfy the significant cooling
demands of the heat-generating equipment. Historically, cooling
equipment within this subsector has commonly used HCFC-22, moving to R-
410A and to a lesser extent R-407C after the 2010 ban on production of
HCFC-22 for new equipment. Historically, some facilities may have been
cooled by chillers using CFC-12, particularly if the facilities date
back to before the 1994 CFC production and consumption phaseout, or
they may use HFC-134a; nonetheless, with the establishment of this
subsector under subsection (i) of the AIM Act, EPA considers such
equipment to be within its own subsector rather than the chillers
subsector, both subject to a 700 GWP limit. As communications and
information technology has developed over the past few decades, the
heat produced and the cooling demand has increased significantly,
complicating designs in consideration of the weight and location of the
cooling equipment and how these issues might impact structural
requirements of the facility.
    Comment: Several commenters requested that equipment used to cool
data centers, computer rooms, server farms, and ITEFs, including
chillers for this market, should not be included within the IPR
subsector, and should instead either be classified as its own subsector
or included under the residential and light commercial AC subsector.
Several commenters described the system design and refrigerant
selection of data center and IT equipment cooling as closer to those
for building AC applications than those for IPR, including indirect
cooling through AC by chillers or direct expansion (DX) systems.
Commenters noted that such equipment indirectly cools through AC
equipment rather than through refrigeration as in IPR, and that new
technologies such as dielectric fluids for direct contact systems and
full immersion chip heat exchangers are also being used. Additionally,
some of these commenters noted that data center, ITEF, and computer
room cooling equipment has higher heat loads than traditional AC
equipment, and although it may be more similar to equipment in the
residential and light commercial AC subsector than to that in the IPR
subsector, considerably larger refrigerant charges (per square foot of
the building being cooled) differentiate this equipment from that in
those two subsectors.
    Commenters also highlighted that data center, ITEF, and computer
room cooling equipment falls within the scope of the UL Standard 20335-
2-40, 4th edition, which covers electrical heat pumps, air
conditioners, and dehumidifiers, and not UL 60335-2-89, which covers
commercial refrigeration equipment used in IPR. Commenters therefore
recommended that EPA consider data centers, ITEF, and computer room
cooling equipment to be a separate subsector, similar to how DOE
classifies this type of cooling equipment under their energy
conservation standards. Further, commenters asserted that data center,
ITEF, and computer room cooling equipment are subject to unique
operating conditions and important safety considerations not shared by
other subsectors, such as year-round cooling and non-stop, continuous
cooling operation and technical designs that maintain temperatures in a
wide range of weather conditions, in addition to reliability mandated
by the critical nature of the equipment.
    Commenters also noted that EPA's original SNAP rulemaking and
Applicability Determination Index document for control number C960015
do not include IT cooling equipment within the definition of IPR (59 FR
13037, March 18, 1994). Other commenters noted that CARB defined this
type of cooling equipment under ``Air Conditioning Equipment.''
    Response: EPA agrees with commenters that the cooling needs for
data centers, ITEFs, and computer rooms are sufficiently different from
those of industrial processes to merit a separate subsector. As
commenters noted, equipment for this purpose has been granted its own
annex in the 4th edition of UL 60335-2-40, ``Household and Similar
Electrical Appliances--Safety--Part 2-40: Particular Requirements for
Electrical Heat Pumps, Air Conditioners and Dehumidifiers,'' and is in
the process of being added to ASHRAE 15-2022, ``Safety Standard for
Refrigeration Systems.'' EPA proposed to include data centers and
server farm cooling equipment within the IPR subsector. Based on a
review of the comments, including information on how the availability
of substitutes for data centers, ITEF, and computer rooms can be
affected by the safety standards covering the equipment, EPA has
decided to consider data center, ITEF, and computer room cooling
equipment as a separate subsector, independent of the IPR subsector,
for the purposes of establishing GWP restrictions for this equipment.
    Additionally, rather than including data center, ITEF, and computer
room cooling equipment in the residential and light commercial AC
subsector, also covered by the UL 60335-2-40 safety standard, EPA
agrees with most commenters that the significantly larger charge sizes
and delays in being addressed by safety standards warrant independent
evaluation of the availability of substitutes for this subsector.
    EPA recognizes how defining categories of equipment consistently
with other regulatory authorities can minimize confusion for
stakeholders. However, while CARB considers IT cooling equipment to be
part of residential and light commercial AC and SNAP considers this
equipment to be part of IPR, in this rulemaking EPA is establishing a
separate subsector to enable EPA to evaluate the availability of
substitutes for use in data center, ITEF, and computer room cooling
equipment together, independently of other similar equipment types.
Therefore, EPA is finalizing a separate subsector to better consider
the (i)(4) factors, and particularly the availability of substitutes
under (i)(4)(B) when setting restrictions on the use of HFC and HFC
blends in new data center, ITEF, and computer room cooling equipment.
What restrictions on the use of HFCs is EPA establishing for data
center, ITEF, and computer room cooling equipment?
    EPA is prohibiting the installation of new data center, ITEF, and
computer room cooling equipment that uses HFCs

and HFC blends with GWPs of 700 and above beginning January 1, 2027.
EPA proposed to consider equipment in this subsector to fall within
IPR, with a 150 GWP limit for equipment with charge capacities greater
than or equal to 200 lb and a 300 GWP limit for equipment with charge
capacities less than 200 lb and for the high temperature side of
cascade systems, effective January 1, 2025. However, after review of
the comments received and consideration of the subsection (i)(4)
factors of the AIM Act, EPA is finalizing a separate subsector for data
center, ITEF, and computer room cooling equipment to allow evaluation
of the availability of substitutes in consideration of the
significantly different technical specifications of equipment designed
for this purpose.
    In considering the availability of substitutes for data center,
ITEF, and computer room cooling equipment under subsection (i)(4)(B),
EPA identified several substitutes that could replace the higher-GWP
substances, such as R-410A, that will be restricted under this rule.
Finalizing a GWP limit of 700 allows the use of available substitutes
that meet the technical requirements for this subsector, notably the
high heat loads generated in the area in which the computer equipment
is installed. These available substitutes include HFO-1234ze(E) and R-
513A, for which equipment has recently been introduced, as well as
refrigerants being developed and implemented in other AC subsectors,
such as HFC-32 (GWP 675) and R-454B (GWP 465). As the technology
develops, other available refrigerants with even lower GWPs may prove
practicable for this subsector, including nonflammable refrigerants R-
744 (GWP 1), R-471A (GWP 144), R-480A (GWP 291), and R-482A (GWP 144),
or additional A2L refrigerants such as R-454A (GWP 237), R-454C (GWP
146), and R-457A (GWP 137).
    Comment: EPA received many comments requesting a 700 GWP limit for
data center, ITEF, and computer room cooling equipment. Given the
technological similarities to residential AC equipment and chillers,
commenters explained that this type of equipment therefore also
requires additional substitutes above 150 to 300 GWP to meet its
cooling needs. One such commenter pointed to refrigerants historically
used in data center, ITEF, and computer room cooling equipment as also
used in commercial AC, such as the high-pressure refrigerant R-410A and
to a lesser extent, R-407C. Thus, this commenter requested the
continued use of high-pressure substitutes identified for commercial AC
equipment, R-454B and HFC-32, with GWPs up to 675. Another commenter
noted how IT cooling equipment is subject to requirements under UL
60335-2-40, showing its congruence to other subsectors within this
standard's scope, while another highlighted an insufficient number of
suitable components, specifically compressors, currently available for
use by the industry with refrigerants below the proposed 150 or 300 GWP
limit. Additionally, a commenter asserted that the high-pressure
operating conditions of IT cooling equipment relative to residential
and commercial AC equipment further limit the number of suitable
refrigerants for this subsector, and that the proposed 150 or 300 GWP
limit would impose excessive economic costs without appreciable
environmental gains.
    Response: As noted in the discussion above, EPA agrees that data
center, ITEF, and computer room cooling equipment is sufficiently
different from other IPR applications to warrant creating a distinct
subsector, separate from IPR. While EPA identified alternatives in the
proposed rule below the proposed threshold, EPA understands from the
commenters that the operating conditions for this subsector suggest a
higher GWP limit is appropriate. Therefore, EPA is finalizing a 700 GWP
limit for data center, ITEF, and computer room cooling equipment. In
establishing a distinct subsector for this equipment, EPA evaluated the
refrigerant options available for use, in consideration of the factors
under subsection (i)(4) of the AIM Act, in IT cooling equipment
independently of IPR. The Agency is establishing a 700 GWP limit rather
than the proposed GWP restrictions on use of HFCs and HFC blends for
IPR of 150 or 300 GWP based on a review of the comments and
reconsideration of the (i)(4) factors, including a review of the
relevant safety standards and technological challenges for this new
subsector. EPA determined that there would be an insufficient number of
available substitutes for these particular uses under the proposed
restrictions.
    Moreover, the type of equipment used in this new subsector is
generally similar to equipment for residential and light commercial AC
and chillers for comfort cooling, which are all covered by the safety
standard UL 60335-2-40. EPA proposed, and is now finalizing, GWP limits
of 700 for residential and light commercial AC and chillers for both
comfort cooling and IPR in this rule. Analogous technical challenges
remain for equipment in the data center, ITEF, and computer room
cooling equipment subsector transitioning to substitutes with GWPs
lower than 700. EPA notes that challenges associated with compressors
and other components, requiring continued use of higher-pressure
refrigerant options, such as HFC-32 and R-454B, also apply to equipment
in this subsector. For further discussion on EPA's decision to set a
700 GWP limit for chillers for comfort cooling and IPR and for
residential and light commercial AC, see sections VI.F.1.j and
VI.F.1.k.
    As noted by commenters, data center, ITEF, and computer room
cooling equipment faces even greater obstacles than those for smaller
equipment within the scope of UL 60335-2-40. Refrigerant capacities
necessary to cool high-heat load equipment and spaces are significantly
greater than those typical of residential and light commercial AC
equipment, highlighting the need for a 700 GWP limit for this type of
equipment. The challenges of using flammable refrigerants to cool
sensitive data and information systems 24/7 in facilities, requiring
100 percent reliability compared to other types of AC equipment, were
also stressed by commenters in their request for EPA to consider IT
cooling equipment separately from IPR. Commenters who requested a
separate subsector unanimously agreed that setting GWP restrictions at
the same level as residential and light commercial AC and chillers for
IPR would offer a sufficient number of available substitutes, provided
there is adequate time to transition. Therefore, EPA is establishing
the same GWP restrictions for the manufacture and installation of new
equipment in this subsector as in other analogous AC subsectors. The
Agency has identified many refrigerant substitutes that are likely to
meet the requirements of this subsector that are below this GWP limit,
including HFC-32, R-454B, and R-513A, with the possibility to also use
R-450A, R-452B, R-454A, R-454C, and R-457A, considering the additional
time provided for the reasons discussed in the response to comments
below. The list of available substitutes includes the nonflammable
options R-450A and R-513A, which may be used where flammable
refrigerants remain prohibited for safety reasons or are not
technologically achievable.
    Comment: EPA received many comments regarding the proposed January
1, 2025, compliance date for IPR as it would apply to data center,
ITEF, and computer room cooling equipment. Many commenters requested
additional time to comply with GWP restrictions, in addition to higher
limits. Several

commenters requested a January 1, 2029, compliance date, while one
requested the compliance date be no earlier than January 1, 2027, or
later than January 1, 2029, and another generally stated IT cooling
equipment may need additional time beyond 2026. Two commenters
expressed support for the proposed date, provided EPA finalized a GWP
limit of 700.
    Commenters requested compliance dates two years or more later than
those proposed. These commenters noted a variety of reasons for this
request, including time needed for IT equipment cooling design,
prototyping, and testing; accommodation for 20-month lead-times for
component manufacturing; and time to train designers and regulators on
new provisions in codes and safety standards. Other commenters noted
that the UL standard allowing for the use of lower-GWP A2L refrigerants
in data centers, ITEF, and computer room cooling equipment was updated
relatively recently in December 2022.\90\ These commenters highlighted
that SNAP has yet to adopt the most recent edition of UL 60335-2-40,
and requested additional time for SNAP to incorporate the updates
included in the 4th edition. A commenter also asked for additional time
to allow further safety standard development, such as finalizing
Addendum ``t'' to ASHRAE 15-2022, which would address IT cooling
equipment, specifically.
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    \90\ 4th edition of UL Standard 60335-2-40.
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    Certain commenters stated that building codes currently prohibit
use of flammable lower-GWP substitutes in this subsector. Commenters
also noted that building codes are updated on a fixed development cycle
and that adopting A2L refrigerants into these codes may take many
years.
    Response: EPA has identified available substitutes that meet the
restrictions for this subsector, given the similarity of the equipment
to equipment in the residential and light commercial AC subsector and
chillers for comfort cooling and the identical GWP limits. However, EPA
is finalizing a January 1, 2027, compliance date for data center, ITEF,
and computer room cooling equipment, providing additional time
consistent with a review of the subfactors in subsection (i)(4)(B). In
particular, the updates to safety standard UL 60335-2-40, allowing
sufficiently large charge sizes of A2L refrigerants to be used in this
equipment, were only published in December 2022. Thus, the regulatory
evaluations under SNAP, equipment redesign and testing, and updates to
building codes that typically follow updates to UL safety standards are
all in somewhat early stages. The additional time for compliance
provided by this final rulemaking will enable updates to the UL
standard, and future harmonizing updates to ASHRAE 15-2022, to be
incorporated in these areas, increasing the number of available
substitutes for use in this subsector by January 1, 2027. See sections
VI.E.2.c and VI.E.2.d for further discussion on how EPA considers these
factors in its evaluation of substitutes.
    EPA is finalizing a date that the Agency has determined to be
reasonable after reviewing the comments and applying the subsection
(i)(4) factors to this new subsector. While some commenters asked for
compliance dates beyond the January 1, 2027, date being finalized, the
Agency does not agree that more time is reasonable. Design and testing
of substitute refrigerants in equipment for this subsector is already
underway, and a number of non-flammable refrigerants that meet the GWP
restrictions for some equipment are already available (e.g., R-513A and
R-744). Certain server farms are cooled exclusively with water through
direct evaporative cooling.\91\ Commenters also noted that new
technologies such as dielectric fluids for direct contact systems and
full immersion chip heat exchangers are other possible cooling methods.
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    \91\ https://sustainability.fb.com/wp-content/uploads/2022/02/Public-Water-Reporting_Expanding-the-Operating-Envelope.pdf.
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    Equipment used for the purposes of cooling IT equipment generally
resembles traditional AC equipment, cooling either through indirect
chillers or DX systems. The Agency understands that the high heat load
of data centers, ITEF, and computer rooms can be very large compared to
typical building cooling; however, by allowing continued use of certain
high-pressure refrigerants, such as HFC-32 and R-454B, challenges
associated with designing new equipment will be minimized. Further,
building codes must also be updated for many other subsectors that are
likely to transition at least partly to flammable refrigerants, such as
retail food refrigeration, IPR, residential and light commercial AC,
and chillers, among others, and such industries have indicated
confidence that such updates can be completed by compliance dates
finalized in this rule.
    The Agency has therefore determined that setting the compliance
date for new manufactures and installations in this subsector beginning
January 1, 2027, is reasonable for the reasons discussed above.
c. Retail Food Refrigeration
    Retail food refrigeration is characterized by storing and
displaying food and beverages, generally for sale, at different
temperatures for different products (e.g., chilled and frozen food).
The designs and refrigerating capacities of such equipment vary widely.
Retail food refrigeration is composed of four main categories of
equipment, and EPA is treating these categories as separate subsectors
under the Technology Transitions program: stand-alone equipment in
retail food refrigeration (hereafter, ``stand-alone units'');
refrigerated food processing and dispensing equipment; remote
condensing units in retail food refrigeration (hereafter, ``remote
condensing units''); and supermarket systems.\92\
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    \92\ By ``supermarket systems,'' EPA means systems that operate
with racks of compressors installed in a machinery room where
different compressors turn on to match the refrigeration load
necessary to maintain temperatures using direct or indirect (e.g.,
cascade) systems. These systems are described further in the section
of the rule pertaining specifically to retail food refrigeration--
supermarket systems, section VI.F.1.c.iv. Grocery stores, warehouse
stores, convenience stores, supermarkets, and bodegas may not use a
``supermarket system'' as described in this rule and instead may be
using stand-alone units and/or remote condensing units. The presence
of a refrigeration system in a supermarket does not on its own mean
that it falls within the retail food refrigeration--supermarket
subsector.
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What restrictions on the use of HFCs is EPA establishing for new retail
food refrigeration?
    EPA proposed a 150 GWP limit across retail food refrigeration, with
exceptions for remote condensing units and supermarket systems with
refrigerant charge capacities greater than or equal to 200 lb, and for
the high temperature side of these subsectors' cascade systems, where a
300 GWP limit would apply. After review of the comments, EPA is
finalizing the GWP limits as proposed for retail food refrigeration in
stand-alone units, remote condensing units, and supermarket systems.
For refrigerated food processing and dispensing equipment covered by
edition 7 of UL Standard 621, Ice Cream Makers (UL 621) and for
equipment with charge sizes greater than 500 g, EPA is not finalizing a
GWP limit, but rather prohibiting the use of certain refrigerants. For
refrigerated food processing and dispensing equipment not covered by UL
621 and with charge sizes less than or equal to 500 g, EPA is
finalizing the 150 GWP limit as proposed.
    EPA proposed a January 1, 2025, compliance date for all four
categories of retail food refrigeration. After review

of the comments, EPA is finalizing a January 1, 2025, compliance date
for stand-alone units, as proposed. For remote condensing units, EPA is
finalizing a compliance date of January 1, 2026. For supermarket
systems, EPA is finalizing a compliance date of January 1, 2027. For
refrigerated food processing and dispensing equipment, EPA is
finalizing different compliance dates depending on the specific
equipment: January 1, 2028, for equipment within the scope of UL 621;
January 1, 2026, for other refrigerated food processing and dispensing
equipment with charge sizes of 500 g or less; and January 1, 2027, for
other refrigerated food processing and dispensing equipment with charge
sizes greater than 500 g.\93\ After review of the comments on the
proposed rule and the availability of HFC and HFC-blend substitutes for
these subsectors, and considering the subsection (i)(4) factors under
the AIM Act, the Agency concludes that finalizing these restrictions on
the use of regulated substances by the specified timeframes is
appropriate.
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    \93\ Commenters noted that some refrigerated food processing and
dispensing equipment utilizes two refrigeration systems: one to
process the food/drink and a separate one to cool a holding tank to
maintain the food/drink at the required temperature. In those
situations, each separate refrigeration system must comply with the
applicable HFC restrictions.
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    EPA received comments regarding the proposed restrictions and
compliance dates applicable across the entire retail food refrigeration
subsector, which are addressed in this section. EPA also received
comments that addressed issues specific to certain subsectors within
retail food refrigeration, and those are summarized and responded to
separately, below.
    Comment: Many commenters addressed the proposed GWP limits for the
entire retail food refrigeration subsector. Most commenters from
industry generally supported the proposed GWP limits. One industry
commenter requested increases to the proposed GWP limits to that of
existing, readily available refrigerants such as R-513A (GWP 630) and
R-449A (GWP 1,396), citing lack of trained technicians to service and
install new systems, unavailability of lower-GWP refrigerant options,
safety concerns, and disproportionate economic burden on disadvantaged
communities. The commenter noted that the refrigerants EPA identified
with GWPs less than 150 for this subsector, such as R-454C, R-471A, and
R-455A, have not been SNAP-approved for use in a retail environment.
The commenter pointed out that the flammability of these substitutes
poses significant health and safety concerns, and also stated that the
toxicity concerns of substitutes like R-717 prevents their widespread
adoption across the subsector. Further, the commenter asserted that R-
744 is not a viable option for retail food refrigeration in many cases
due to efficiency concerns, leak detection challenges, costs, and other
technological constraints associated with a high-pressure refrigerant.
    Several environmental groups urged EPA to lower the proposed GWP
limits in the retail food refrigeration subsector. One organization
recommended that EPA adopt a 150 GWP limit across retail food
refrigeration, regardless of charge size, citing adequate availability
of existing refrigerant options. As discussed in section VI.F.1.c.i,
they asserted that the 300 GWP limit for certain charge sizes and
systems was unnecessarily high and overly complicated, could provide
potential for a regulatory loophole, and could stifle innovation of
very low-GWP refrigerants.
    Response: EPA has considered comments requesting uniform
restrictions across retail food refrigeration--those seeking both
increased and decreased stringency from EPA's proposed limits--and has
determined that uniform restrictions and compliance timeframes are not
appropriate, given the differences in availability of substitutes for
use in these subsectors. EPA proposed GWP limits for retail food
refrigeration based on the availability of substitutes specific to each
subsector. For these four subsectors, EPA considered all subsection
(i)(4)(B) factors to the extent practicable, including carefully
evaluating the circumstances associated with technological
achievability of substitutes given the varying equipment types,
location of the equipment, servicing challenges, and technological
specifications and constraints. Selecting a single GWP limit for all
retail food refrigeration oversimplifies the technologies and
substitutes available for use in this subsector. Therefore, the Agency
discusses available HFC and HFC-blend substitutes in the following
sections to describe the appropriateness of the finalized GWP limits in
the context of each subsector.
    EPA does not agree with commenters seeking a higher GWP limit for
all retail food refrigeration subsectors. As discussed in the List of
Substitutes TSD and in the sections that follow, EPA has considered, to
the extent practicable, the subsection (i)(4)(B) factors and identified
lower-GWP refrigerant substitutes that are available for use to meet
the Agency's GWP limit. To the extent that the availability of some
substitutes is currently constrained for certain uses within the retail
food refrigeration subsectors, such as R-454C and R-455A, as noted by
one commenter, EPA has considered those constraints and is providing
additional time for compliance for some of the subsectors and uses.
Since issuing the proposed rule, EPA has listed R-471A as acceptable
for use in these subsectors.
    EPA does not agree that the concerns raised by a commenter--
potential lack of trained technicians, unavailability of lower-GWP
refrigerant options, and safety concerns--warrant establishing a
uniformly higher GWP limit for the four retail food refrigeration
subsectors. The Agency has analyzed these concerns specific to the
systems and equipment in each subsector within retail food
refrigeration and adjusted the restrictions and compliance timeframes
as appropriate. For example, the concerns raised by a commenter about
R-744 and R-717 use in retail food refrigeration are relevant to
certain subsectors where these options have been identified as
substitutes, such as in supermarket systems, but not necessarily
others. Such considerations are discussed in the context of the
relevant subsectors rather than in this section, which applies
generally to all of retail food refrigeration.
    EPA also does not agree that it would be appropriate to establish
uniform GWP limits across the retail food refrigeration subsector,
regardless of the charge size of equipment. For further discussion on
EPA's decision to finalize GWP restrictions based on a 200 lb
refrigerant charge capacity threshold for certain subsectors, see
section VI.F.1.a.
    With respect to those commenters seeking GWP limits below 150, the
Agency acknowledges that some refrigerants identified as available for
use, such as R-744 and R-717, meet that threshold, but EPA does not
agree that it is appropriate to adopt restrictions based only on the
lowest GWP substitutes. Doing so would inappropriately limit the
overall availability of substitutes for that subsector (see section
VI.E.5). Setting restrictions at least at 150 GWP for the subsectors in
retail food refrigeration ensures that multiple available substitutes
may be used, which eases constraints on commercial demands, costs, and
training needs specific to certain substitutes. Allowing a variety of
substitutes acknowledges the fact that not every substitute can be used
for every application within a subsector

and ensures a smooth transition from higher-GWP HFCs.
    Comment: EPA received many comments supportive of the proposed GWP
limits that requested additional time to comply. Some commenters
requested a January 1, 2026, compliance date, noting several concerns
affecting the subsector's ability to meet the January 1, 2025, date.
Other commenters requested a much longer timeframe for compliance for
the retail food refrigeration subsector, including compliance dates
that would not become effective until January 1, 2032.
    A couple of commenters who requested additional time for compliance
noted the delayed updates to UL Standard 60335-2-89 in the 2nd edition,
published in October 2021, relative to publication dates of similar
updates to other industry standards (e.g., UL 60335-2-40 and ASHRAE
15). They highlighted how it takes time for updates in safety standards
to be adopted and implemented. After a safety standard is updated, it
must be reflected in equipment testing and certification, manufacturing
facility updates, building codes, and be adopted where appropriate
under SNAP. The commenter stated that the updated UL Standard 60335-2-
89, which covers commercial refrigeration, has not yet been fully
incorporated and addressed in these ways. Commenters stated that the
retail food refrigeration subsector has fewer available substitutes
than other subsectors (such as residential AC and heat pumps) where the
updates to their applicable UL standards were published earlier.
Therefore, these commenters asserted that additional time for
compliance with the GWP limits for retail food refrigeration would
allow for manufacturers to design and test equipment to comply with the
updated UL standards and address other concerns, such as building code
adoption, that could limit the ability to install and operate such
equipment. The commenters assert that without this extra time, it would
be unreasonable to consider certain refrigerant substitutes,
particularly certain flammable substitutes, to be ``available.''
    The need for more time to test new equipment and refrigerants was
highlighted by a few commenters. Two commenters noted that providing
further time for compliance would help NRTLs test and list equipment
using new lower-GWP substitutes prior to the compliance date.
Additional time was also requested to evaluate the safety and
efficiency of systems using flammable refrigerants, which the commenter
stated have yet to be evaluated by retailers for effectiveness.
According to commenters, after such systems are evaluated,
manufacturing facilities would need to be upgraded for the safe storage
and handling of flammable refrigerants. One commenter highlighted how
the retail food refrigeration subsector's role in providing groceries
and supplies to the public mandates 24/7 reliability, and that some
systems using low-GWP substitutes, such as R-744, are not yet reliable.
This commenter stated that additional time would allow them to develop
and test systems to ensure that they meet all of the sector's
reliability, performance, and safety requirements.
    Additionally, commenters noted that building codes in certain areas
could impede the transition to substitute refrigerants because they
currently do not allow for use of flammable refrigerants in new
buildings. These commenters requested a delay in the compliance date to
allow those jurisdictions to continue to update their codes to reflect
the expanding list of safe, lower-GWP refrigerant options in response
to updated safety standards.
    Finally, commenters highlighted that relevant SNAP listings for
refrigerants in retail food refrigeration, in response to the updates
to UL 60335-2-89, have yet to be finalized. Commenters cited additional
SNAP listings for A2Ls and expanded charge sizes for R-290 in this
subsector as necessary to comply with the proposed GWP limits, and that
additional time would provide the opportunity for EPA to finalize
pertinent SNAP listings before the compliance date.
    Response: EPA has considered these comments and agrees that
additional time for compliance is appropriate in some instances. EPA
does not agree that such additional time is required for every
subsector in retail food refrigeration, and therefore addresses these
concerns and requests for extensions in the subsector-specific sections
that follow. This section discusses in general terms the extent to
which EPA considered how the timing of UL standards' publications
impacts other factors that inform availability of substitutes for
retail food refrigeration as part of the decision to provide a later
compliance date.
    Most retail food refrigeration equipment falls under the scope of
safety standard UL 60335-2-89. In October 2021, the 2nd edition of this
standard was published, updating safety requirements so that flammable
and lower flammability refrigerants could be deployed more widely in
commercial refrigeration equipment. EPA recognizes the time it can take
for an updated UL standard to be widely incorporated and for the
updates to be applied across industry. Many other relevant changes
affecting the availability of substitutes and facilitating transition
to the use of those substitutes generally occur after the UL standard
is updated, including evaluation of substitutes under the SNAP program,
adoption of new editions into building codes, equipment testing and
certification, safety updates to manufacturing facilities, and training
of technicians. All of these are considerations for EPA's assessment of
availability of substitutes under subsection (i)(4)(B). Further
discussion on how updates to UL 60335-2-89 affect the availability of
substitutes for equipment within the safety standard's scope can be
found in section VI.E.2.
    Typically, following updates to safety standards for retail food
refrigeration, EPA evaluates substitutes through the SNAP program's
comparative risk framework, where the Agency considers safety by
assessing exposure assessments, toxicity data, and flammability, among
several regulatory criteria. EPA is currently evaluating many of the
refrigerants impacted by the updates to UL 60335-2-89 and has proposed
to list many refrigerants as acceptable, subject to use conditions,
under SNAP for use across retail food refrigeration (88 FR 33722, May
24, 2023). Although those evaluations under SNAP are ongoing, the
Agency anticipates that given the number of substitutes currently
proposed as acceptable for use, users in the retail food refrigeration
subsector will likely have an expanded set of available substitutes
from which to choose in the coming years. EPA has considered its
ongoing retail food refrigerant evaluations under SNAP on a subsector-
specific basis, and the adjusted compliance timeframes reflect these
evaluations and their potential impact on the availability of
substitutes for use in each individual subsector. Further discussion on
the intersection of SNAP listing decisions and AIM Act subsection
(i)(4) can be found in section VI.E.2.
    As noted by many commenters, building codes can limit refrigerants
available for use based on their flammability, the charge size of the
equipment, and other relevant safety factors, and take time to adopt
changes to safety standards. These code updates are generally made in
each specific jurisdiction, and the timeframe for adoption of new
editions of safety standards can vary greatly. In certain
jurisdictions, users may be unable to utilize certain flammable
substitutes identified by EPA for use in retail food refrigeration,
even if they are SNAP-

approved, until building codes incorporate the updates in the 2nd
edition of UL 60335-2-89. However, EPA may still consider a substitute
to be available before every building code in every jurisdiction across
the United States permits its use. See section VI.E.2.d for discussion
on EPA's consideration of building codes and the availability of
substitutes under subsection (i)(4).
    Further, EPA agrees with commenters that updates to UL standards
must also be incorporated into equipment design, testing, and
certifications. Even after manufacturers develop equipment using
substitutes, NRTLs must certify that the new equipment meets UL safety
standards. NRTL equipment certification requires substantial testing,
site visits, and labor input before new equipment can be used. For a
subsector as large as retail food refrigeration, NRTLs could struggle
to complete certification of new equipment by the proposed January 1,
2025, compliance date for the subsector.
    EPA also anticipates that the use of lower-GWP refrigerant options
like R-744, with very high pressure, or the use of flammable
substitutes may require more specialized training. Such trainings are
available and underway, but more trained technicians would benefit the
commercial refrigeration industry in the transition to lower-GWP
refrigerants.
    EPA agrees with the commenter that manufacturing facilities not
currently using flammable refrigerants will need to incorporate safety
updates before using flammable refrigerants on site. EPA acknowledges
that these changes to manufacturing facilities could require financial
and time investments; however, the use of flammable refrigerants has
steadily increased over the last ten years, meaning some manufacturers
have already made such upgrades. In the cases where these updates have
yet to be made, EPA understands that they could delay when those
facilities are able to factory-charge new substitutes into their
appliances or pre-charged components.
    EPA has therefore determined, in consideration of the need for
certain SNAP approvals, updates to building codes, equipment design,
testing, and certifications, technician trainings, and manufacturing
facility upgrades, that providing additional time to comply is
reasonable for certain subsectors in retail food refrigeration.
Considering these factors, noted by many commenters, the Agency is
finalizing delayed compliance dates for certain refrigerated food
processing and dispensing equipment, remote condensing units, and
supermarket systems. This additional time will provide an opportunity
for additional SNAP listings to be finalized; jurisdictions to consider
the latest edition of UL 60335-2-89 and incorporate the updated safety
requirements into their building codes to enable the use of certain
substitutes; further development, testing, and certification of
equipment using new substitutes; a greater number of specialized
trained technicians; and completion of remaining safety updates to
facilities.
    EPA understands that the lagging effects of updating UL 60335-2-89
do not affect stand-alone units and certain refrigerated food
processing and dispensing equipment in the same way. Therefore, EPA is
finalizing the compliance date of January 1, 2025, for stand-alone
units and certain refrigerated food processing and dispensing equipment
as proposed. Further discussion on EPA's decision to finalize the
compliance dates for these subsectors can be found in sections
VI.F.1.c.i and VI.F.1.c.ii.
i. Retail Food Refrigeration--Stand-Alone Units
    Stand-alone units are equipment where all refrigeration components
are integrated and, for the smallest types, the refrigeration circuit
is entirely brazed or welded. Stand-alone units are charged with
refrigerant at the factory and typically require only an electricity
supply to begin operation. Examples include refrigerators, freezers,
and reach-in coolers (either open or with doors). EPA considers these
to be products according to the definition of stand-alone units
finalized in this rulemaking.
    Medium-temperature stand-alone units maintain a temperature above
32 [deg]F (0 [deg]C). Most are typically designed to maintain food and
beverages at temperatures roughly between 32 [deg]F (0 [deg]C) and 41
[deg]F (5 [deg]C). Low-temperature stand-alone units are designed to
maintain food and beverages at temperatures roughly between -40 [deg]F
(-40 [deg]C) and 32 [deg]F (0 [deg]C) (i.e., freezers). Today, HFC-134a
is the most commonly used refrigerant in stand-alone units, with R-404A
also commonly used in low temperature applications and some high-
capacity applications.
What restrictions on the use of HFCs is EPA establishing for new stand-
alone units and why?
    EPA is prohibiting the manufacture and import of stand-alone units
that use HFCs and HFC blends with a GWP of 150 or greater beginning
January 1, 2025. This GWP limit applies to new stand-alone units,
irrespective of compressor capacity or evaporator design. After review
of the comments received, EPA is finalizing these restrictions as
proposed.
    Comment: In addition to the general retail food refrigeration
comments discussed in section VI.F.1.c, EPA received comments on the
proposed GWP limits for stand-alone units, specifically. One commenter,
a private citizen, expressed support for the 150 GWP limit. Another
commenter requested a 300 GWP limit for stand-alone units, claiming
that refrigerants between 150 and 300 GWP offer increased energy
efficiency benefits and require smaller charge sizes. In particular,
the commenter advocated for a limit that accommodates the use of R-454A
(GWP 237), which they asserted is the only substitute that can exceed
the capacity of the refrigerant currently used by the commenter, R-
404A, and the use of which would allow for a fast and simple
transition. According to the commenter, the only other substitute
identified by EPA with comparable volumetric capacity that would meet
the 150 GWP limit is R-455A (GWP 146), which the commenter claimed
poses non-ideal glide conditions for equipment transitioning out of R-
404A. The commenter stated that EPA was not permitted to rely on State
HFC regulations to fulfill its statutory duty to evaluate substitutes
under the AIM Act, that EPA was required to comply with AIM Act
subsection (i)(5), and that there was no indication in the record that
EPA had complied with the requirement in subsection (i)(4)(A) to
consider best available data.
    Response: After review of the general retail food refrigeration
comments and the comments specific to stand-alone units, EPA is
finalizing the GWP limits for stand-alone units as proposed. The Agency
agrees with the comment that a 150 GWP limit is appropriate for this
subsector. The Agency disagrees with the commenter requesting a 300 GWP
limit for stand-alone units, given the availability of substitutes with
GWPs below 150 for use in this subsector under subsection (i)(4).
Further, EPA does not agree with the commenter's assessment that the
Agency has not relied on best available data in determining the
availability of substitutes nor do we agree that EPA was obligated to
evaluate substitutes under (i)(5) in carrying out a rulemaking (see
section VI.E.1).
    The commenter asserts that EPA should revise its restriction for
stand-alone units on the basis that its preferred substitute, R-454A,
is the only

currently available substitute that ``can exceed'' the volumetric
capacity of R-404A. But subsection (i)(4) does not require EPA to set
restrictions in a way that would accommodate transition only when the
substitutes under consideration outperform the regulated substances
currently being used. While setting a limit at 300 would permit the use
of more substitutes than the Agency's limit of 150, and therefore
potentially provide a ``faster and simpler'' transition for this
subsector, that does not mean that the substitutes identified by the
Agency for use in stand-alone units are not ``available.'' The
commenter does not demonstrate that the substitutes EPA identified as
currently available for use in stand-alone units cannot be used, for
instance by adjusting or reengineering equipment models to overcome
issues of volumetric capacity,\94\ or that EPA should not have
considered any of its identified substitutes to be available per any of
the subsection (i)(4)(B) factors. Further, as noted elsewhere, EPA has
recently proposed to approve additional alternatives (e.g., R-454C, R-
455A, R-457A, and R-516A) and increase the allowable charge size for
existing alternatives (e.g., R-290), that may address the commenter's
concern (88 FR 33722, May 24, 2023). Tests on HFC/HFO blends such as R-
454C, R-455A, and R-457A show a volumetric capacity either identical or
varying in the range of 5 percent, compared to HCFC-22,
indicating that the blends should not create a significant change in
volumetric capacity that would require reengineering.\95\ The Agency's
assessment is that a 150 GWP limit is appropriate for stand-alone units
after considering the (i)(4) factors, to the extent practicable, and,
particularly relevant to the commenter's points, after evaluating under
(i)(4)(B) the availability of substitutes for use in these units. We
also note that EPA's ongoing evaluation of additional substitutes under
the SNAP program, including for use in stand-alone units, may
facilitate the availability of more options for compliance by January
1, 2025. EPA continues to encourage innovation of refrigerants that
meet these restrictions and anticipates the number of substitutes
available for use in stand-alone units will continue to grow.
---------------------------------------------------------------------------

    \94\ In most cases, little or no reengineering will be required
to use HFC/HFO blends in place of regulated substances. The largest
amount of reengineering will be required for R-744, due to its
higher pressure, and for the hydrocarbon refrigerant R-290, because
of its higher flammability. However, industry is already in the
process of adopting those refrigerants. For example, R-290 is
already being used to replace R-404A in retail food stand-alone
units like ice cream cabinets and plug-in display cases. (RTOC,
2022)
    \95\ RTOC, 2022. TEAP 2022 Progress Report (May 2022) available
at: https://ozone.unep.org/science/assessment/teap.
---------------------------------------------------------------------------

    For new equipment, the Agency has identified R-744 (GWP 1), R-290
(GWP 3.3), R-600a (GWP 1), R-441A (GWP 3), HFO-1234ze(E) (GWP 1), and
HFO-1234yf (GWP 1) as available substitutes for the higher-GWP HFCs
currently used in stand-alone units. In addition to their lower GWPs,
some of these substitutes offer additional environmental and economic
benefits via increased energy efficiency. Multiple sources, not peer-
reviewed, indicate that R-290 offers significant efficiency benefits as
compared to traditional higher-GWP refrigerants used for commercial
refrigeration, claiming reduced energy usage of 11 to 63 percent for R-
290 models compared to similar equipment using HFC-134a \96\ and
reduced energy consumption of approximately 30 percent with R-290
compared to R-404A.\97\ A peer-reviewed study found that energy use in
a stand-alone freezer unit can be reduced as much as 34 percent,
depending on operating conditions, when using R-290 instead of R-
404A.\98\
---------------------------------------------------------------------------

    \96\ True Manufacturing, 2019, Hydrocarbon (Natural Refrigerant)
Brochure. Available at: https://www.truemfg.com/support/resource-center/#panel2.
    \97\ Carel, March 2020. Six Reasons to Use Propane as
Refrigerant. Available at: https://www.carel.com/blog/-/blogs/six-reasons-to-use-propane-as-refrigerant.
    \98\ Mastrullo, Rita & Mauro, Alfonso & Menna, Laura & Vanoli,
G.P. (2014). Replacement of R404A with propane in a light commercial
vertical freezer: A parametric study of performances for different
system architectures. Energy Conversion and Management. 82. 54-60.
10.1016/j.enconman.2014.02.069.
---------------------------------------------------------------------------

    Use of R-290, R-600a, and other lower-GWP refrigerants in stand-
alone equipment has increased significantly in recent years,
particularly since SNAP Rules 17, 19, and 21 listed various substitutes
as acceptable and provided use conditions that enable these
substitutes, including those that are flammable, to be used safely (76
FR 78832, December 20, 2011; 80 FR 19454, April 10, 2015; and 81 FR
86778, December 1, 2016). EPA is aware of several available low and
medium temperature stand-alone unit models using substitutes such as R-
290 and R-600a. Commercial demand exists for equipment types that use
R-290, including reach-in refrigerators and freezers, beverage coolers,
and food service equipment, as well as beverage coolers and vending
machines that use R-744.\99\ These lower-GWP refrigerants have had
significant use in other regions of the world.\100\ The increased
prevalence of these substitutes in stand-alone equipment indicates
their availability for use in this subsector, both in terms of
technological achievability and commercial demand.
---------------------------------------------------------------------------

    \99\ See Commercial Demands and Technological Achievability TSD
in the docket for a list of products in the affected sectors and
subsectors using substitutes.
    \100\ See TEAP 2022 Assessment Report, section 5.
---------------------------------------------------------------------------

    Several States have legal restrictions on the use of high-GWP HFCs
and HFC blends in stand-alone equipment.\101\ These restrictions became
effective between 2020 and 2022. Stand-alone equipment using lower-GWP
substitutes in compliance with State regulatory requirements are
currently being sold in these markets, clearly indicating that these
types of equipment can use substitutes that are available. The Agency
does not agree with the commenter that EPA has relied on State
prohibitions to fulfill its statutory duty under subsection (i). We
have factored in, to the extent practicable, those factors in
subsection (i)(4) in determining the use restrictions finalized in this
action. The Agency discussed in the proposed rule and a TSD that the
State regulations prohibiting the use of HFCs and requiring the use of
substitutes is one source of information that is relevant to EPA's
assessment of the availability of substitutes in stand-alone units,
particularly in terms of technological achievability. See the
Availability of Substitutes TSD for further information on available
HFC and HFC-blend substitutes for stand-alone units.
---------------------------------------------------------------------------

    \101\ California, Colorado, Delaware, Maine, Maryland,
Massachusetts, New Jersey, New York, Rhode Island, Virginia,
Vermont, and Washington.
---------------------------------------------------------------------------

    In addition to the lower-GWP refrigerants already available, EPA
continues to evaluate substitutes under the SNAP program and has
authority to do so under subsection (i)(5) of the AIM Act as well. The
Agency anticipates that this continuing evaluation of additional
substitutes, including for use in stand-alone units, may help
facilitate the availability of even more options for compliance by
January 1, 2025. For example, under the SNAP program, EPA has proposed
to list several additional refrigerants that would comply with the
final restrictions as acceptable, subject to use conditions, for use in
stand-alone units: HFO-1234ze(E), HFO-1234yf, R-457A, R-516A, R-455A,
and R-454C (with GWPs of 1, 1, 137, 140, 146, and 146, respectively)
(88 FR 33722, May 24, 2023). Concerning the ability to meet appliance
efficiency standards, one study found R-454C, R-455A, and R-457A
reduced energy consumption by 2.07 to 2.45 percent, 2.95 to 2.9
percent,

and 10.48 to 10.69 percent, respectively, compared to R-404A in a
stand-alone unit.\102\ To the extent that a manufacturer chooses not to
use a specific refrigerant because of glide, R-744, R-600a, R-290, HFO-
1234ze(E), and HFO-1234yf are all single component refrigerants and
therefore have no glide, and R-516A has been listed under ASHRAE
Standard 34 as an azeotropic blend, with glide comparable to that of R-
404A. The Agency therefore does not agree with the commenter urging EPA
to establish GWP limits for stand-alone units that are less stringent
than the limit proposed, given that the best available data indicate an
existing array of available substitutes.
---------------------------------------------------------------------------

    \102\ Ranges represent without a receiver to with a receiver.
Llopis, Rodrigo, et al., International Journal of Refrigeration,
June 2019. DOI: 10.1016/j.ijrefrig.2019.06.013, available at: http://www.energiazero.org/aermec/gas/Llopis_Low_GWP_R404A_MT_final.pdf.
---------------------------------------------------------------------------

    Comment: EPA received comments requesting an extension of the
proposed January 1, 2025, compliance date for stand-alone units. One
commenter noted that HFC/HFO-blends often have significantly lower GWPs
than HFC-only refrigerants, and that SNAP has listed many HFC blends as
acceptable for stand-alone units, implying relatively minimal
environmental impact of their continued use. They agreed that although
many manufacturers of stand-alone units have already transitioned to R-
290 (GWP 3.3), others chose non-flammable SNAP-approved refrigerants
that would not meet the new 150 GWP limit. According to the commenter,
additional time is needed for these manufacturers, whose products
include ENERGY STAR certified units with non-flammable HFC/HFO blends,
to transition to lower-GWP options. Another commenter pointed to the
recent updates to UL 60335-2-89 allowing for increased charge sizes up
to 500 g for A3 refrigerants in stand-alone units. The commenter
concluded that increased charge sizes are necessary to move to
substitutes with GWPs less than 150 and that if SNAP does not address
larger charge sizes for flammable refrigerants in the next several
months, then the compliance date should be delayed until January 1,
2026.
    A third commenter cited the need for an additional year for
research and development to manufacture new equipment that will meet
DOE energy efficiency requirements, for coordinating with compressor
and other component manufacturers, and for NRTLs to work through a
``backlog'' of testing that will result from the transition. They also
noted that building codes still need to be updated to allow for use of
flammable refrigerants and that manufacturing facilities need time for
redesigns to safely handle them.
    Response: After review of the general retail food refrigeration
comments and the comments specific to stand-alone units regarding the
proposed January 1, 2025, compliance date, EPA is finalizing the
compliance date as proposed. HFC and HFC blends already identified by
the Agency as available substitutes can support the final GWP limits
for new stand-alone units. In addition, this rule would not prevent a
manufacturer from seeking and receiving ENERGY STAR certification for
units using refrigerants with a GWP less than 150. Numerous models
using the lower-GWP refrigerants R-290 or R-600a, for example, are
already listed under the ENERGY STAR Product Finder,\103\ as well as
those using the higher-GWP, non-flammable HFC/HFO blends mentioned by
the commenter.
---------------------------------------------------------------------------

    \103\ See www.energystar.gov/productfinder.
---------------------------------------------------------------------------

    As discussed above, EPA has taken into account the delayed
publication of updates to UL standard 60335-2-89 and the subsequent
incorporation of those updates by electing to extend the compliance
dates for many subsectors in retail food refrigeration. However, the
Agency does not agree that for stand-alone units, a delay in the
January 1, 2025, compliance date is appropriate. In general, charge
sizes for stand-alone units are relatively small, and stand-alone units
containing A3 refrigerants have been in use for several years. The
transition to lower-GWP substitutes is further along than in other
subsectors within retail food refrigeration. Therefore, challenges
associated with the need to update building codes; evaluate substitutes
under SNAP; research, develop, test, and certify equipment; update
manufacturing facilities; and ensure an adequate supply of trained
technicians are less present for smaller charge refrigeration
equipment. For other retail food subsectors with complications that
could contribute to delays in their transition, EPA is providing
additional time to comply for the reasons discussed in the section
above.
ii. Retail Food Refrigeration--Refrigerated Food Processing and
Dispensing Equipment
    Refrigerated food processing and dispensing equipment is designed
to make or process and subsequently dispense cold food and beverages,
including equipment that functions as a holding tank to deliver the
food or beverage at the desired temperature or to deliver chilled
ingredients for their processing, mixing, and preparation. This
equipment can be self-contained or can be connected via refrigerant
piping to a dedicated condensing unit located elsewhere. Some may use a
refrigerant in a heat pump or utilize waste heat from the unit to
provide hot beverages. Some may also provide heating functions to melt
or dislodge ice or for sanitation purposes. Examples include equipment
used to make and dispense chilled and frozen beverages; frozen
custards, gelato, ice cream, Italian ice, sorbets and yogurts;
milkshakes, ``slushies'' and smoothies; and whipped cream.
    Refrigerated food processing and dispensing equipment historically
used CFC-12 and HCFC-22 and has more recently adopted HFC-134a and R-
404A in medium and low temperature applications, respectively. Both
HFC-134a and R-404A are potent GHGs with GWPs of 1,430 and 3,922,
respectively.
What restrictions on the use of HFCs is EPA establishing for new
refrigerated food processing and dispensing equipment and why?
    For new refrigerated food processing and dispensing equipment, EPA
proposed a 150 GWP limit restriction that would take effect starting
January 1, 2025. EPA received comments, summarized and responded to
below, that pointed out that much of the equipment in the refrigerated
food processing and dispensing subsector is covered by a different UL
standard (UL 621) that has not yet been revised to enable the effective
use of flammable refrigerants for certain charge sizes. EPA has
therefore modified the proposed restrictions in this final action by
establishing different restrictions and compliance dates where
availability of substitutes is constrained by these factors.
    Specifically, in new stand-alone refrigerated food processing and
dispensing equipment that is outside the scope of UL 621 and has a
refrigerant charge size less than or equal to 500 g, EPA is setting a
GWP limit of 150 GWP, as proposed, but beginning two years later than
proposed, on January 1, 2027. For new refrigerated food processing and
dispensing equipment with a charge size greater than 500 g, within the
scope of UL 621, and for systems that use remote condensing units, EPA
is not finalizing a GWP limit restriction as proposed, but is instead
prohibiting the use of the following HFCs or HFC blends, which have
GWPs as high or higher than HFC-134a: R-402A, R-402B, R-404A, R-407A,
R-407B, R-407C, R-407F, R-

407H, R-408A, R-410A, R-410B, R-411A, R-411B, R-417A, R-417C, R-420A,
R-421A, R-421B, R-422A, R-422B, R-422C, R-422D, R-424A, R-426A, R-427A,
R-428A, R-434A, R-437A, R-438A, R-507A, HFC-134a, HFC-227ea, R-125/290/
134a/600a (55/1/42.5/1.5), RB-276,\104\ RS-24 (2002 formulation), RS-44
(2003 formulation), GHG-X5, or Freeze 12 (within this section, EPA
refers to this list as the ``prohibited refrigerants''). New self-
contained refrigerated food processing and dispensing equipment with
charge sizes greater than 500 g outside the scope of UL 621 and systems
that use remote condensing units must comply with the prohibitions
beginning January 1, 2027. New stand-alone equipment within the scope
of UL 621 must comply with the prohibitions beginning January 1, 2028.
---------------------------------------------------------------------------

    \104\ RB-276 is also known as Free Zone and HCFC Blend Delta.
---------------------------------------------------------------------------

    Comment: In addition to the general retail food refrigeration
comments, EPA received a comment from a private citizen in support of
the proposed 150 GWP limit for refrigerated food processing and
dispensing equipment, specifically. Another commenter approved of the
150 GWP limit, but only for equipment that is self-contained and with
charge sizes less than or equal to 500 g. Commenters also requested
greater GWP limits than proposed for this subsector. One commenter
requested a 3,920 GWP limit to apply to refrigerated food processing
and dispensing equipment, while another requested a 1,450 GWP limit for
remote condensing units and equipment with charge sizes greater than
500 g. This commenter discussed the applicability of certain safety
standards (e.g., UL 621 versus UL 60335-2-89) to various refrigerated
food processing and dispensing equipment and noted that flammable
refrigerants are not yet permitted in equipment within the scope of UL
621 with charges greater than 150 g, greatly limiting the number of
available substitutes. Additionally, EPA received comments requesting
an exception for refrigerated food processing and dispensing equipment
within the scope of UL 621.
    Response: After review of the general retail food refrigeration
comments and the comments specific to refrigerated food processing and
dispensing equipment regarding the proposed 150 GWP limit, EPA is
finalizing the GWP limit as proposed for stand-alone equipment outside
the scope of UL 621 with charge sizes less than or equal to 500 g. EPA
agrees with the commenters who expressed their support of the proposed
GWP limit for this type of equipment, and understands the available HFC
and HFC-blend substitutes to be sufficient to replace refrigerants with
GWPs greater than 150 for this type of equipment. EPA initially
identified substitutes such as R-744 and R-717 as available for use in
this subsector for its consideration of availability of substitutes
under subsection (i)(4)(B) for the HFCs and HFC blends that EPA is
restricting. EPA acknowledges that in some situations, particularly in
public areas, R-717 may not be allowed by building codes or may be
limited in the charge size allowed. R-744 technology continues to
advance, allowing for improved appliance energy efficiency in climates
found in most of the United States. Additionally, companies expressed
interest in using other lower-GWP substitutes for this subsector, with
one commenter indicating they are already using refrigerants like R-290
(GWP 3.3) in some of their equipment. Proposed SNAP Rule 26 listings
for refrigerated food processing and dispensing equipment, enabled by
updates to UL 60335-2-89 and other safety standards, will likely
provide further refrigerant options for such types of stand-alone
equipment outside the scope of UL 621 and with charge sizes less than
or equal to 500 g, once finalized. EPA has proposed to list HFO-
1234ze(E), HFO-1234yf, R-290, R-457A, R-516A, R-455A, R-454C, R-454A
(with GWPs of 1, 1, 3.3, 137, 140, 146, 146, and 237, respectively) as
acceptable, subject to use conditions, under SNAP for use in
refrigerated food processing and dispensing equipment (88 FR 33722, May
24, 2023). All but one of these substances meet the GWP limit of 150
for this type of equipment in this subsector, further easing the
transition to lower-GWP refrigerants. EPA continues to encourage
innovation of refrigerants that meet these restrictions and anticipates
the number of substitutes available for use in refrigerated food
processing and dispensing equipment will continue to grow.
    The Agency therefore disagrees with commenters requesting a higher
GWP limit or an exemption uniformly across all types of refrigerated
food processing equipment, given the identified available substitutes
below 150 GWP for this type of equipment. EPA is aware of actions being
taken in various States and local jurisdictions that have or will amend
building codes that will increase the availability of substitutes by
permitting additional substitutes, including certain flammable
substitutes, with GWPs below the proposed GWP limit.\105\ See section
VI.E.2.d for further discussion on EPA's consideration of building
codes in identifying available substitutes under subsection (i)(4) of
the AIM Act.
---------------------------------------------------------------------------

    \105\ See the TSD on building codes in the docket for additional
information on building codes and list of substitutes.
---------------------------------------------------------------------------

    For self-contained products within the scope of UL 621, for self-
contained products with charge sizes greater than 500 g, and for
refrigerated food processing and dispensing systems using remote
condensers, EPA is not finalizing a GWP limit as proposed, and is
instead prohibiting certain listed refrigerants. The Agency agrees with
commenters that these types of equipment face additional challenges to
using lower-GWP substitutes. Prohibiting specific refrigerants retains
the use of nonflammable options even if such equipment is not added to
the scope of UL 60335-2-89 or other appropriate safety standards to
allow for additional flammable options in the necessary charge sizes.
In addition, refrigerant options for units with charge sizes greater
than 500 g or for systems using remote condensing units may not be
supported by the expected updates to the safety standards. Therefore,
the Agency finds that a more reasonable approach to transitioning such
refrigerated food processing and dispensing equipment to lower-GWP
options is by prohibiting higher-GWP refrigerants such as R-404A and
HFC-134a. The GWPs of the prohibited refrigerants range from 1,430
(HFC-134a) to 3,985 (R-507, R-507A), which is similar to the request of
one commenter to set a GWP limit of 1,450 for certain types of
refrigerated food processing and dispensing equipment. One commenter
indicated it has already transitioned some of its equipment to R-449A,
which is not one of the prohibited refrigerants. Other nonflammable
options, such as R-448A and R-449B, are also available for these types
of equipment and EPA has proposed further low-GWP options. As stated in
section VI.B of this preamble, this approach--restricting specific
substances instead of setting a GWP limit for a given subsector--gives
EPA time to identify an appropriate GWP limit for this subsector while
still restricting those substances that have the highest adverse
environmental impact.
    Comment: EPA received several comments on the proposed January 1,
2025, compliance date for various types of refrigerated food processing
equipment. Many comments requested

additional time for compliance for refrigerated food processing and
dispensing equipment within the scope of UL 621--Ice Cream Makers--
relative to other applications in this subsector. These comments noted
that equipment within the scope of UL 621, such as ice cream, yogurt,
custard, and milk shake machines, are not covered by the UL 60335-2-89
standard, and that UL 621 does not yet contain updated safety
requirements enabling the use of flammable refrigerants in necessary
charge sizes. Additional time to allow for analogous updates to UL 621,
as in the 2nd edition of UL 60335-2-89, was requested, ranging from two
to six years, including one request that the compliance date for
equipment covered by UL 621 be no earlier than six years after updates
to that standard are published, or that such equipment be exempted
outright. Until updates have been made to UL 621 to allow for use of
flammable refrigerants, commenters requested additional time to comply
with restrictions (in this case, the prohibited refrigerant list in
lieu of a GWP limit) for equipment within the scope of UL 621 or with
charge sizes greater than 500 g. One commenter noted the proposed
January 1, 2025, compliance date for this type of equipment (remote
condensing units or stand-alone units with charges greater than 500 g)
as appropriate if the Agency raises the GWP limit to 1,450.
    Other issues related to the compliance date for all types of
refrigerated food processing and dispensing equipment were flagged by
commenters such as building codes, time for NRTLs to test and list new
equipment, glide issues with using A2Ls in direct contact cooling
applications, time to source compressors and other components
appropriate for use with flammable refrigerants, and design challenges
for equipment using the lower-GWP substitutes identified by the Agency.
One commenter discussed how food service equipment has unique testing
requirements and must be certified by the National Sanitation
Foundation standard, which could take an additional four to six months.
The commenter stated that equipment must also meet DOE efficiency
standards, and was concerned about hydrocarbon refrigerants working
efficiently in larger charge equipment. This commenter requested a 5-
to 10-year extension of the proposed compliance date for this
subsector.
    Other commenters noted that UL 621 does not currently allow toxic
refrigerants such as R-717, a substitute identified by EPA for use in
refrigerated food processing equipment. According to these commenters,
using higher toxicity refrigerants (ASHRAE Standard 34 safety group
classification ``B'' substances) in equipment for producing fresh food
for consumption could potentially lead to harm if ingested by the
consumer under circumstances of a refrigerant leak. Commenters also
pointed to challenges of transitioning to high-pressure refrigerants,
such as R-744, in small equipment. For these reasons, commenters
requested a delayed compliance date for refrigerated food processing
and dispensing equipment under the scope of UL 621 (e.g., ice cream
makers) with charge sizes less than or equal to 500 g.
    Response: After review of the comments related to refrigerated food
processing and dispensing equipment and consideration of the (i)(4)
factors, EPA is finalizing a compliance date of January 1, 2027, for
self-contained equipment outside the scope of UL 621 (for both those
with charge sizes less than or equal to 500 g and those with charge
sizes greater than 500 g) and for refrigerated food processing and
dispensing equipment with a remote condenser. EPA is establishing a
January 1, 2028, compliance date for self-contained refrigerated food
processing and dispensing products within the scope of UL 621.
    After further evaluation of the substitutes available to this
subsector, EPA agrees that the proposed January 1, 2025, compliance
date would not provide sufficient time for refrigerated food processing
and dispensing equipment within the scope of UL 621. The current status
of UL 621 limits the availability of flammable lower-GWP refrigerants
for use in equipment covered by that standard. EPA agrees with
commenters that for equipment in this subsector within the scope of UL
621, additional time is warranted to ensure the availability of
technologically achievable refrigerants. In particular, approximately
two more years will be needed to update UL 621, or incorporate this
type of equipment into another standard such as UL 60335-2-89, to
support the use of lower-GWP, flammable refrigerants and then another
two years for EPA to list substitutes for use with UL 621 if those
mentioned above do not prove feasible and for manufacturers to design
and test equipment following the updated UL 621 standard. EPA is
therefore finalizing a compliance date of January 1, 2028, to provide
additional time for publication of updates to UL 621 to allow the use
of flammable refrigerants. However, EPA disagrees that a delay of up to
ten years following updates to UL 621 or an outright exemption for
equipment within the standard's scope would be appropriate, given the
updates that are already underway for this subsector.
    EPA is delaying the compliance dates for other equipment in this
subsector to allow further progress under SNAP evaluations, safety
standards, equipment design, and building codes. EPA finds a two-year
delay to January 1, 2027, to be sufficient for stand-alone equipment
not covered by UL 621 with charge sizes less than or equal to 500 g
because UL 60335-2-89 addresses some types of self-contained
refrigerated food processing and dispensing equipment allowing up to
500 g of A3 refrigerants. While similar equipment in the stand-alone
unit subsector has already begun using hydrocarbon refrigerants such as
R-290 in recent years, review of these substitutes for use in
refrigerated food processing and dispensing equipment is still ongoing
under SNAP and necessitates further research, development, and testing
of equipment using substitutes that meet the 150 GWP restriction.
Therefore, the Agency is finalizing a compliance date of January 1,
2027, for stand-alone equipment not covered by UL 621 with charge sizes
less than or equal to 500 g.
    In alignment with many commenters, EPA is also delaying the
compliance date by two years, to January 1, 2027, for refrigerated food
processing and dispensing equipment outside the scope of UL 621 with
either a greater than 500 g charge size (for self-contained equipment)
or with a remote condenser. EPA appreciates that one commenter found
the proposed January 1, 2025, compliance date appropriate for equipment
with larger charge sizes, given the tremendous product development the
organization has already completed for refrigerants below 1,450 GWP.
However, after considering the comments as a whole, and that the list
of prohibited refrigerants for these types of equipment may not exactly
conform with the GWP limit suggested by the commenter agreeing to a
2025 compliance date, EPA is providing two additional years to comply
for this class of equipment. This additional time will allow
manufacturers to investigate and implement substitutes such as R-448A,
R-449A, and R-449B (all A1 refrigerants) for types of equipment that
would not be able to use A3 refrigerants such as R-290 or R-600a under
the UL 60335-2-89 safety standard. It will also provide time for
resolution of current obstacles to adopting A2L refrigerants such as
building codes, testing, development, and certification of equipment,
and pending SNAP listings. EPA disagrees that a compliance delay of up
to ten years would be appropriate

for this type of equipment, given the updates that are already underway
for this subsector, including an updated UL safety standard and
availability of substitutes.
iii. Retail Food Refrigeration--Remote Condensing Units
    The third category of equipment under retail food refrigeration,
remote condensing units, exhibit refrigerating capacities typically
ranging from 1 kW to 20 kW (0.3 to 5.7 refrigeration tons) and are
composed of one (and sometimes two) compressor(s), one condenser, and
one receiver assembled into a single unit, 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. A cascade system might be used, e.g., to
reach low temperatures in a long-term storage room. Remote condensing
units are commonly installed in convenience stores and specialty shops
such as bakeries and butcher shops. Having historically used HCFC-22,
newly manufactured units now primarily use R-404A or HFC-134a. Other
HFC blends--including R-407A, R-407C, R-407F, and R-507A--are also
used.
What restrictions on the use of HFCs is EPA establishing for systems
using new remote condensing units and why?
    EPA is finalizing GWP limits for remote condensing units as
proposed. Analogous to supermarket systems, IPR systems, and cold
storage warehouses, EPA is distinguishing systems using remote
condensing units by their refrigerant charge capacity. See section
VI.F.1.a for a discussion of EPA's decision to finalize this
distinction. Systems with refrigerant charge capacities greater than or
equal to 200 lb have a GWP limit of 150. Systems with refrigerant
charge capacities less than 200 lb, and for the high temperature side
of cascade systems irrespective of the charge capacity, have a GWP
limit of 300.\106\ In response to comments, and after further
consideration of the (i)(4) factors, EPA is finalizing a compliance
date of January 1, 2026, rather than January 1, 2025.
---------------------------------------------------------------------------

    \106\ The GWP limit for the low temperature side of a cascade
system, either 150 or 300, is based on the refrigerant capacity of
the low-side system. The 300 GWP limit applies to the high
temperature side of a cascade system regardless of the total
refrigerant capacity.
---------------------------------------------------------------------------

    Comment: In addition to the retail food refrigeration comments that
are applicable to this subsector, discussed in section VI.F.1.c, EPA
received comments from several environmental groups requesting more
stringent restrictions for systems using remote condensing units
related to the varying technical distinctions of the equipment. In
general, commenters urged EPA to lower the proposed GWP limits,
decrease the proposed 200 lb charge size threshold to 50 lb or remove
it entirely, and/or remove the distinction for the high temperature
side of cascade systems.
    One such commenter urged a 10 GWP limit for all charge sizes of
remote condensing units, pointing to R-744 as the only currently
acceptable option below the 150 GWP limit for supermarkets, an example
they claim applies similarly to remote condensing units. The commenter
expressed confusion concerning EPA's decision to set GWP limits up to
300 when other refrigerant options in the 10 to 300 GWP range will be
unavailable for use before the proposed January 1, 2025, compliance
date. Further summary of comments related to the differing GWP limits
based on technical distinctions in IPR, supermarket systems, remote
condensing units, and cold storage warehouses can be found in the IPR
section, VI.F.1.a.
    Response: After reviewing the comments, EPA is finalizing GWP
limits for this subsector as proposed. These final limits are
consistent with comments supporting the GWP limits proposed for the
entire retail food refrigeration sector and are supported by the
substitutes identified by the Agency as available for use in remote
condensing units under subsection (i)(4)(B). EPA identified available
substitutes for the restricted substances, including R-744 (GWP 1) and
R-717 (GWP 1). R-744 remote condensing units are commercially available
in several global markets, including in the United States. EPA's SNAP
program recently listed R-471A (GWP 144) and R-515B (GWP 287) as
acceptable in supermarket systems (September 8, 2023, 88 FR 61977).
Additionally, EPA has proposed to list HFO-1234ze(E), HFO-1234yf, R-
457A, R-516A, R-455A, R-454C, R-454A (with GWPs of 1, 1, 137, 140, 146,
146, and 237, respectively) as acceptable, subject to use conditions,
under SNAP for use in supermarket systems (88 FR 33722, May 24, 2023).
Other technologically achievable substitutes that may potentially
become available in the future for supermarket systems in the high
temperature side of a cascade system or where charge capacities are
less than 200 lb, include R-480A (GWP 291) and R-457B (GWP 249). All of
these substances would meet the GWP limit of 300 for this subsector,
and all except R-454A and R-457B meet the GWP limit of 150. The already
available substitutes have been evaluated by EPA to be sufficient to
meet these restrictions while the potential for a greater array of
options in the future will further ease the transition to lower-GWP
refrigerants. EPA continues to encourage innovation of refrigerants
that meet these restrictions and anticipates the number of substitutes
available for use in retail food remote condensing units will continue
to grow.
    Comment: EPA did not receive comments on the proposed January 1,
2025, compliance date specific to remote condensing units, though the
Agency did receive comments regarding the proposed compliance dates for
retail food refrigeration generally.
    Response: After consideration of the subsection (i)(4) factors
under the AIM Act, EPA is finalizing a January 1, 2026, compliance date
rather than the proposed date of January 1, 2025, for remote condensing
units. For EPA's response to these comments and discussion on the
Agency's decision to provide an additional year to comply, see section
VI.F.1.c.iv.
iv. Retail Food Refrigeration--Supermarket Systems
    Supermarket systems are the fourth category of equipment under
retail food refrigeration, also known as multiplex or centralized
systems. They operate with racks of compressors installed in a
machinery room where different compressors turn on to match the
refrigeration load necessary to maintain temperatures. Two main designs
are used: direct and indirect systems. In a direct system, 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. Supermarket
walk-in cold rooms are often integrated into the system and cooled
similarly, but a dedicated condensing unit can be provided for a given
storage room.
    Indirect supermarket designs include secondary loop systems and
cascade refrigeration systems.\107\ Indirect systems use a chiller or
other refrigeration system to cool a secondary fluid that is then
circulated throughout the store to the cases. Compact chiller versions
of an indirect system rely on a lineup of 10-20 units, each using small
charge sizes. As the refrigeration load changes, so does the number of
active chillers. Each compact chiller is an independent unit with its
own

refrigerant charge, reducing the potential volume of refrigerant that
could be released from leaks or catastrophic failures. Despite the term
``chiller'' used in the description, these systems are considered
supermarket systems under this rulemaking.
---------------------------------------------------------------------------

    \107\ See section VI.F.1.a of this preamble for a description of
cascade systems.
---------------------------------------------------------------------------

    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 5 to 10 such systems in a store.
    Supermarket rack systems historically used CFC-12, R-502, HCFC-22,
and other blends containing HCFCs in a centralized design. While some
of these systems remain in use, others have been retrofitted to replace
the ODS refrigerant using a blend containing an HFC (e.g., R-404A, R-
422A, R-422B, R-422D, R-427A, R-438A, and R-507A) or have been replaced
with a newly manufactured system with refrigerant blends containing
HFCs (e.g., R-404A, R-507A, R-407A, R-407C, and R-407F). More recently,
some new supermarket systems have also been using non-fluorinated
refrigerants, such as CO2, or HFC/HFO blends, such as R-
448A, R-449A, and R-449B.
What restrictions on the use of HFCs is EPA establishing for
supermarket systems?
    Analogous to remote condensing units, IPR systems, and cold storage
warehouses, EPA is distinguishing larger and smaller supermarket
systems by their refrigerant charge capacity. See section VI.F.1.a for
a discussion of the safety standards driving this distinction. EPA is
prohibiting the installation of new supermarket systems using HFCs and
HFC blends with a GWP of 150 or greater when the refrigerant charge
capacities are greater than or equal to 200 lb, beginning January 1,
2027. For new supermarket systems with refrigerant charge capacities
less than 200 lb, and for the high temperature side of cascade systems
irrespective of the total charge capacity, EPA is establishing a GWP
limit of 300,\108\ beginning January 1, 2027.
---------------------------------------------------------------------------

    \108\ The GWP limit for the low temperature side of a cascade
system, either 150 or 300, is based on the refrigerant capacity of
the low-side system. The 300 GWP limit applies to the high
temperature side of a cascade system regardless of the total
refrigerant capacity.
---------------------------------------------------------------------------

    EPA is finalizing GWP limits for supermarket systems as proposed;
however, in response to comments received on the proposal and in
consideration of the subsection (i)(4)(B) factors under the AIM Act,
the Agency is finalizing a compliance date that is two years later than
proposed (i.e., January 1, 2027, rather than January 1, 2025).
    For its consideration of availability of substitutes under
subsection (i)(4)(B), EPA identified substitutes that are available in
place of the restricted substances for systems with larger refrigerant
charge capacities. These include R-717, which can be used in a
secondary loop (indirect) supermarket refrigeration system, and R-744,
which can be used for centralized direct and indirect supermarket
refrigeration systems. Further, the restrictions EPA is finalizing
would allow for the use of HFC/HFO blends. For example, EPA has
recently proposed HFC/HFO blends R-454C, R-457A, R-455A, and R-516A as
acceptable for use in supermarket systems under SNAP (88 FR 33722, May
24, 2023) and all have GWPs below the 150 limit. Further, EPA's SNAP
program has listed additional lower-GWP substitutes as acceptable for
use in supermarket systems (88 FR 61977, September 8, 2023) since
issuing the proposed rule, including R-471A and R-515B (with GWPs of
144 and 287, respectively). Other lower-GWP refrigerants that might
become available in the future include HFC/HFO blends such as R-459B,
R-465A, R-468A, R-476A, R-479A, and R-482A .
    These final restrictions support the transition to lower-GWP
substitutes and innovative technologies that have been used widely in
other parts of the world, such as Europe and Canada, and have seen
increased use in the United States. EIA maps multiple supermarkets
where lower-GWP refrigerants are being used, which includes Texas and
Florida.\109\ EPA's GreenChill Partnership includes a Certified Store
program where individual food retail stores voluntarily submit
applications detailing the types of refrigerants used in the store,
refrigerant emissions, and refrigerant quantities; to date, 47 percent
of certified stores have used refrigerants with a GWP less than 150,
primarily R-744. The number of platinum-level certified stores in the
South, Southwest, and Southeast regions, most using refrigerants with a
GWP less than 150, increased 40 percent from 2021 to 2022.\110\
ATMOsphere indicated that as of December 2022 there were over 1,000
stores globally using transcritical CO2 systems.\111\ The
global market of transcritical R-744 systems, which are manufactured by
multiple U.S. companies, was expected to grow at a compound annual
growth rate of 12.69 percent between 2018 and 2025.\112\ R-744 systems
may also provide additional environmental and economic benefits via
increased energy efficiency in some cases, though R-744 systems can
experience declining efficiencies in high ambient temperatures.
---------------------------------------------------------------------------

    \109\ https://www.climatefriendlysupermarkets.org/map, accessed
August 29, 2023.
    \110\ ``GreenChill Certified Store Achievements,'' web page,
accessed September 20, 2023. Available at: https://www.epa.gov/greenchill/greenchill-certified-store-achievements.
    \111\ ATMOsphere (2023). Natural Refrigerants: State of the
Industry. Available at: https://issuu.com/shecco/docs/2022_atmo_marketreport.
    \112\ Global Transcritical CO2 Systems Market by
Function (Refrigeration, Air Conditioning, Heating), Application
(Heat Pumps, Food Processing, Others), Region, Global Industry
Analysis, Market Size, Share, Growth, Trends, and Forecast 2018 to
2025, FiorMarkets, March 2019. Report description available at:
https://www.fiormarkets.com/report/global-transcritical-co2-systems-market-by-function-refrigeration-376006.html.
---------------------------------------------------------------------------

    Comment: In addition to the general retail food refrigeration
comments discussed below, EPA received comments on the proposed GWP
limits specific to supermarket systems. One industry commenter
supported the proposed GWP limits of 150 and 300 based on the 200 lb
charge size, in addition to the 300 GWP limit for the high temperature
side of a cascade system. Another suggested either a 1,500 or 700 GWP
limit, citing difficulties converting supermarkets to A2L refrigerants,
and that EPA should allow economics to be a design factor. Similarly,
another commenter objected to the 300 GWP limit for supermarkets with
charge capacities less than 200 lb, citing heightened impacts on food
deserts, which rely on small, local convenience stores for their access
to food, and typically use smaller refrigerant capacity systems.
Instead, the commenter suggested a 1,500 GWP limit for supermarket
systems with charge sizes less than 50 lb.
    Environmental groups urged EPA to finalize lower GWP limits than
proposed for supermarket systems, decrease the proposed 200 lb charge
size threshold to 50 lb or remove it entirely, and/or remove the
distinction for the high temperature side of cascade systems. One
commenter claimed that there is no need for indirect cascade systems
when the same capacity direct expansion system can be designed with
refrigerants that have GWPs less than 150. Another asserted that
because R-744 is currently used in supermarkets in California, an area
with a hot climate, such systems are therefore suitable for
supermarkets across the country. Another commenter urged a 10 GWP limit
for all charge sizes of supermarket systems, pointing to R-744 as the
only

currently acceptable option below the 150 GWP limit. They discussed how
fluorinated substances like R-454C, with a GWP of 146, are not yet
available on the market, will impose unknown costs to businesses, have
significantly greater potential impacts on global climate change
compared to R-744, and could pose environmental justice concerns not
addressed by the proposed rule. This commenter also stated that having
two GWP limits based on charge size could encourage manufacturers to
move to smaller systems with higher-GWP HFCs instead of transitioning
from HFCs altogether. The commenter expressed confusion over the
Agency's proposal to set GWP limits up to 300, when other supermarket
system refrigerant options in the 10 to 300 GWP range will be
unavailable for use before the proposed January 1, 2025, compliance
date.
    Response: After review of the comments received, the Agency
disagrees with assertions that EPA should adopt GWP limits as high as
700 or 1,500, or as low as 10, for this subsector. Instead, the Agency
has determined that providing additional time for compliance, rather
than increasing GWP limits, is a more appropriate way to address the
concerns raised by commenters about the availability of substitutes for
use in supermarket systems. As discussed in this section, a number of
substitutes for use in this subsector are already currently available
and in use in all regions of the country, and EPA has identified a
number of additional substitutes that will meet the GWP limits at the
levels the Agency proposed that will be available, consistent with the
subsection (i)(4)(B) factors, by January 1, 2027. Therefore, EPA is
finalizing the level of the GWP limits for supermarket systems as
proposed.
    The Agency does not agree that the higher limits suggested by
commenters are reasonable in consideration of subsection (i)(4)(B)
factors, given that many refrigerant options with GWPs lower than 150
and 300 are already available for use in this subsector. As other
commenters noted, currently available substitutes include R-717, which
can be used in secondary loop (indirect) supermarket refrigeration
systems, and R-744, which can be used for centralized direct and
indirect supermarket refrigeration systems. Many supermarket systems in
various regions of the United States already use refrigerants with GWPs
below the GWP limits, including R-744 even in warmer climates.
Additionally, consistent with the Agency's position at proposal that
the options for this subsector will continue expand, EPA's SNAP program
has recently listed two non-flammable blends, R-471A (GWP 144) and R-
515B (GWP 287), as acceptable for use in supermarket systems.\113\
---------------------------------------------------------------------------

    \113\ 88 FR 61977 (Sept. 8, 2023).
---------------------------------------------------------------------------

    Similarly, the Agency does not agree that a higher GWP limit (e.g.,
1,500 GWP) is appropriate for systems with refrigerant charge
capacities less than 200 lb, including those with charge sizes less
than 50 lb as requested by one industry commenter. EPA recognizes that
convenience stores and smaller food retailers can be critical to
communities, sometimes referred to as food deserts, that are not served
by larger supermarkets. However, these establishments often do not use
supermarket systems, as described in this subsector, but rather use
smaller charge systems such as self-contained cases and remote
condensing units. Many currently available models of self-contained
cases are already using refrigerants with a GWP of less than 150, and,
as discussed in section VI.F.1.c.iii., EPA has determined that, given
existing and expanding options of lower-GWP refrigerants, new remote
condensing units will be able to meet the 150 and 300 GWP limits by
January 1, 2026. Even some larger supermarkets are implementing
innovative designs using stand-alone equipment or smaller, remote
condensing units operating with R-744 or hydrocarbon refrigerants, such
as R-290 and R-600a, to supplement, or even replace, supermarket rack
systems. See the Availability of Substitutes TSD for further
information on available HFC and HFC-blend substitutes for supermarket
systems. We therefore do not agree that a GWP limit of up to 1,500 is
necessary to ensure that smaller supermarkets or convenience stores,
which we agree are critical for food security in certain communities,
have options for new equipment.
    In addition to R-744, R-717, and hydrocarbons that are already
available for use in this subsector, and the recently listed R-471A and
R-515B, EPA has proposed to list HFO-1234ze(E), HFO-1234yf, R-457A, R-
516A, R-455A, R-454C, R-454A (with GWPs of 1, 1, 137, 140, 146, 146,
and 237, respectively) as acceptable, subject to use conditions, under
SNAP for use in supermarket systems. All of these substances meet the
GWP limit of 300 for this subsector, and all except R-454A meet the GWP
limit of 150. Although the already available substitutes have been
evaluated by EPA to be sufficient to meet these restrictions, the
potential for a greater array of options in the future will further
ease the transition to lower-GWP refrigerants. EPA continues to
encourage innovation of refrigerants that meet these restrictions and
anticipates the number of substitutes available for use in supermarket
systems will continue to grow. ASHRAE continues to receive applications
for the designation of new refrigerants in the ASHRAE 34 standard.
There has also been a notable increase in submissions for new
refrigerants under EPA's SNAP program for this subsector. As discussed
further in EPA's response to comments regarding the compliance deadline
for supermarket systems, below, EPA understands that allowing
additional time to comply will provide an opportunity for the
applicable UL safety standard updates to be reflected in ways that will
continue to increase the availability of substitutes for use in this
subsector.
    While EPA is not certain what was meant by the comment to ``allow
economics to be a design factor,'' EPA agrees that the AIM Act's
phasedown of HFCs will mean that HFCs will become increasingly scarce,
and scarcity may lead to price increases in the event that demand also
remains high. However, EPA does not agree that the HFC phasedown
established by the AIM Act negates the need to promulgate regulations
under subsection (i) including the establishment of GWP limits for
supermarket systems.
    EPA is also not electing to establish restrictions as low as 10 GWP
for this subsector, even though, as commenters pointed out, some of the
refrigerants available for use in supermarket systems, such as R-744
and R-717, have very low GWPs. EPA does not agree that it is
appropriate to adopt restrictions based only on the lowest GWP
substitutes, as doing so would inappropriately limit the overall
availability of substitutes to meet the restrictions. Rather, EPA has
established limits for this subsector to encourage the continued
development and innovation of substitutes, and to ensure that there
will be sufficient substitutes to support a smooth transition of this
subsector away from higher-GWP HFCs. See section VI.E.5 for further
discussion on EPA's decision not to tailor restrictions to the GWPs of
specific substitutes.
    Regarding the request for EPA to use a 50 lb or lower refrigerant
charge capacity rather than a 200 lb capacity as the threshold between
the 150 GWP limit and the 300 GWP limit, EPA does not agree that a 50
lb refrigerant charge capacity threshold is appropriate in this
context. Further discussion on EPA's decision to finalize the 200 lb
cutoff and the distinction of a high temperature side of cascade
systems when setting

GWP limits can be found in section VI.F.1.a.
    For these reasons, in addition to those described in the Agency's
response to comments that are relevant to all of retail food
refrigeration, EPA is finalizing the 150 and 300 GWP limits for the
supermarket systems subsector as proposed and is extending compliance
dates to mitigate some of the concerns raised by the commenters
regarding availability of substitutes in the near term.
    Comment: In addition to the comments received on compliance dates
applying to all of retail food refrigeration, two commenters urged EPA
to provide additional time to comply for supermarket systems,
specifically. One commenter requested a January 1, 2026, compliance
date to provide additional time for A2L design development. Another
commenter requested flexibility based on availability of refrigerants,
installation availability, and other supply chain constraints and
objected to EPA's inclusion of R-454C, R-471A, and R-455A as available
substitutes given they are not SNAP-approved.\114\ The commenter noted
that even if such options were SNAP-approved, building codes limit the
implementation of A2Ls in supermarkets and would also need to be
updated prior to A2L use. They also referenced challenges related to R-
744 systems, noting strained supply as the global market turns to R-
744, technological challenges, limited technical expertise, and
increases in energy costs when used in warmer climates. Additionally,
one comment from industry appears to apply to the entire retail food
refrigeration section subsector, but EPA considers many of the concerns
described to be mostly relevant to supermarket systems. This comment
requested a 2032 compliance date for retail food refrigeration and can
be found summarized in section VI.F.1.c.
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    \114\ As discussed in section VI.E.2, EPA considers the listing
of substitutes as acceptable under the SNAP program, which evaluates
safety and other characteristics, to be informative in its
evaluation of the availability of those substitutes.
---------------------------------------------------------------------------

    Response: After review of the comments received regarding the
proposed January 1, 2025, compliance date for retail food
refrigeration, generally, and supermarket systems, specifically, EPA is
finalizing a compliance date of January 1, 2027, for supermarket
systems.
    EPA understands that supermarket systems planning to transition to
lower-GWP substitutes may need building codes to be updated before
transitioning to mildly flammable, flammable, or toxic refrigerant
options in certain jurisdictions. As discussed in the Building Codes
TSD, such updates can take several years, and many jurisdictions have
yet to adopt recent editions of safety standards that permit the use of
flammable or toxic refrigerants in larger quantities through the
requirement of additional mitigation strategies. However, to date, the
vast majority of States have amended their regulatory codes or have
passed legislation to specifically permit the use of SNAP-listed low-
GWP refrigerants. Fewer than a dozen States still require additional
legislative or regulatory updates to permit the use of low-GWP
refrigerants in building codes.\115\ EPA is aware of ongoing efforts by
industry groups and other stakeholders to work with State and local
officials to update building codes to allow for alternative
refrigerants. EPA has had and will continue to have discussions
concerning agency rulemaking and meet with relevant stakeholders,
including State officials. In providing two additional years for
compliance, EPA is enabling those remaining jurisdictions to update
their building codes or legislation accordingly, an approach
recommended by many industry commenters. However, EPA can consider a
substitute to be available before every building code in every
jurisdiction across the United States permits its use (see section
VI.E.2).
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    \115\ See Building Codes TSD at 5-6.
---------------------------------------------------------------------------

    EPA recognizes that for certain subsectors, moving to flammable
refrigerants will require new design considerations, equipment testing,
trainings, and safety precautions. However, many food retailers already
use hydrocarbons for other retail food refrigeration subsectors such as
stand-alone units, and that experience will ease the adoption of
flammable refrigerants in this subsector. Design, testing, and
implementation of A2L refrigerants in future stores is underway, but
still ongoing. Therefore, EPA is delaying the compliance date for this
subsector to better accommodate the design cycle of equipment following
adoption of safety standards and to ensure availability of substitutes
for use, as one of the factors considered.
    EPA disagrees that finalizing a compliance date as late as 2032 for
supermarket systems would be appropriate, given that supermarkets
across the country, in varied climates, have already successfully
transitioned to refrigerants meeting the limits finalized in this rule.
As discussed in detail in responses to comments regarding the adoption
of updates to safety standards UL 60335-2-89 in section VI.F.1.c, EPA
considered the impacts and required timing needed to reflect the
updates to those safety standards in building code updates, SNAP
listings, equipment testing and design, and service technician
training, and the Agency accordingly adjusted a number of compliance
deadlines for the restrictions applicable to the retail food
refrigeration subsector. EPA's finalization of the January 1, 2027,
compliance date for the supermarket systems subsector reflects the time
necessary for those remaining issues associated with safety standard
updates to be resolved. We note that the safety standards were updated
in 2021, and many commenters from industry indicated that a one-year
extension to January 1, 2026, would be sufficient to resolve remaining
issues. The additional two years beyond the proposed compliance date
provided in this final action will ensure that the handful of States
and jurisdictions (fewer than a dozen) that do not yet allow for use of
newer refrigerants (e.g., lower flammability refrigerant blends) will
make needed updates to building codes or laws, that industry continues
training technicians to install and service these systems, which EPA
acknowledges will differ compared to other types of servicing needs,
and will provide necessary time for equipment design and testing.
Further, EPA recognizes the costs associated with moving to
substitutes, but the relative cost difference of using substitutes in
place of HFCs will diminish over time as the phasedown continues. The
AIM Act's phasedown of HFCs will mean that HFCs will become
increasingly scarce, and scarcity may lead to price increases in the
event that demand also remains high. In this respect, the estimated
costs are conservative because such effects are not incorporated into
the analysis in the RIA Addendum or the Costs and Environmental Impacts
TSD. Moreover, as detailed in the Costs and Environmental Impacts TSD,
EPA is assuming cost savings accrue over time with the transition to
CO2 supermarket systems. Information from industry
commenters showed that four different types of CO2
supermarket systems displayed lower energy consumption compared to the
baseline system in the most populous city in the United States (New
York), two CO2 supermarket system types resulted in lower
energy use in the second most populous city in the United States (Los
Angeles), and one type of CO2 supermarket system reduced
energy consumption in all

cities shown, by 10% (Houston) to 35% (New York).\116\
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    \116\ January 30, 2023. Available at https://www.regulations.gov
in Document ID No. EPA-HQ-OAR-2021-0643-0209.
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    Although noted as available substitutes in the proposed rule and
TSD, EPA recognizes that refrigerants such as R-454C and R-455A have
not yet been SNAP-approved for use in supermarket systems. However,
following the updates to UL 60335-2-89, discussed in greater detail in
section VI.E.2.c and VI.F.1.c, EPA has proposed to list many additional
refrigerant options as acceptable for use in supermarket systems,
including HFO-1234ze(E), HFO-1234yf, R-457A, R-516A, R-455A, R-454C, R-
454A (with GWPs of 1, 1, 137, 140, 146, 146, and 237, respectively).
Further, since the proposed rule, EPA's SNAP program has listed
additional lower-GWP substitutes as acceptable for use in supermarket
systems (September 8, 2023; 88 FR 61977), including R-471A and R-515B
(with GWPs of 144 and 287, respectively). EPA anticipates that by the
extended deadline of January 1, 2027, manufacturers will have more
available substitutes from which to select for the design of new
systems, and that the additional time will allow further research,
development, and safety testing of new equipment using newer
refrigerants. For these reasons, in addition to those described in the
Agency's response to comments that are relevant to all of retail food
refrigeration, EPA has determined extending the compliance date for
supermarket systems by two years to be reasonable. This approach is
consistent with many of the comments received from industry, including
large trade associations that represent this subsector.
d. Vending Machines
    Vending machines are a type of self-contained commercial
refrigeration product that includes mechanical and electronic
components required to secure, sell, and dispense refrigerated food and
beverages, including cold drinks in cans or bottles, ice cream, milk,
cold drinks in cups, and perishable food items. Hot beverages may also
be provided via a heat pump or through recycled waste heat from the
refrigeration cycle, particularly for dual hot/cold beverage vending
machines.
    Lower-GWP refrigerants, primarily R-290 and R-744, are
technologically achievable for use in vending machines and the use of
these substitutes is increasing, indicating commercial demands. Two of
the largest vending machine customers in the U.S. market, Coca-Cola and
PepsiCo, have been using R-744 over the past decade.117 118
Industry safety standards and model building codes were also revised in
2021 to allow the use of other lower-GWP substitutes. ASHRAE amended
the safety standard ASHRAE 15 to allow vending machines with up to 114
grams of R-290 to be used in locations where they were not previously
allowed under previous editions of industry standards. UL also modified
standard UL 541, ``Standard for Safety for Refrigerated Vending
Machines,'' covering this equipment ``for the unrestricted placement of
vending machines refrigerated with advanced, environmentally-friendly
coolants.'' \119\ Beginning January 1, 2020, the National Automatic
Merchandising Association (NAMA) Foundation partnered with DOE in a
two-year, $400,000 cooperative research and development agreement on
energy efficient vending machines utilizing refrigerants such as R-
290.\120\
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    \117\ Coca-cola, January 2014, Coca-cola Installs 1 Millionth
HFC-Free Cooler Globally, Preventing 5.25MM Metric Tons of
CO2. Available at: https://www.coca-colacompany.com/press-releases/coca-cola-installs-1-millionth-hfc-free-cooler.
    \118\ PepsiCo, 2020. Sustainability Focus Area: Climate.
Available at: https://www.pepsico.com/our-impact/sustainability/focus-area/climate.
    \119\ Karnes, B, March 2021, Revisions to UL 541, the Standard
for Refrigerated Vending Machines. Available at: https://www.ul.com/news/revisions-ul-541-standard-refrigerated-vending-machines.
    \120\ NAMA, 2019. NAMA Foundation Annual Report 2019. Available
at: https://namanow.org/wp-content/uploads/2019-NAMA-Foundation-Annual-Report.pdf.
---------------------------------------------------------------------------

    For its consideration of availability of substitutes under
subsection (i)(4)(B), EPA identified available substitutes in place of
the restricted substances, including R-290 (GWP 3.3), R-600a (GWP 1),
R-744 (GWP 1), and R-441A (GWP 3). Other refrigerants that meet this
GWP limit and are currently under development and evaluation include R-
451A (GWP 147), R-454C (GWP 146), R-455A (GWP 146), R-457A (GWP 137),
R-471A (GWP 144), and R-476A (GWP 147).
What restrictions on the use of HFCs is EPA establishing for vending
machines?
    EPA is prohibiting the manufacture and import of vending machines
that use HFCs and blends containing HFCs that have a GWP of 150 or
greater beginning January 1, 2025. Effective January 1, 2026, EPA is
prohibiting the subsequent sale, distribution, offer for sale or
distribution, or export of new vending machines manufactured or
imported before January 1, 2025, that use HFCs with GWPs that exceed
the limit. EPA is finalizing both the GWP limit and compliance date for
vending machines as proposed.
    Comment: EPA received one comment disagreeing with the proposed 150
GWP limit for vending machines. This commenter requested a 300 GWP
limit instead, citing the proposed limit as unnecessary and
unrealistic.
    Response: EPA disagrees with the commenter that setting a vending
machine GWP limit at 300 would be appropriate. Already, models with
very low-GWP refrigerants such as R-744 and R-290 are available,
providing substitutes for higher-GWP HFCs and HFC blends. For example,
Coca-Cola had installed 1.5 million beverage coolers, fountains, and
vending machines using R-744 or R-290 worldwide and almost 100,000 such
pieces of equipment in North America by 2015.\121\ Further, DOE and
vending machine manufacturers worked together beginning December 2019
and identified R-290 as a ``viable, business-tenable and sustainable
alternative'' to high-GWP refrigerants as of 2022.\122\ Current
information shows that there are refrigerants available with a GWP of
less than 150 for vending machines. Therefore, EPA is finalizing the
GWP limit for this subsector as proposed.
---------------------------------------------------------------------------

    \121\ Coca-Cola's HFC-free cooler count reaches 2.5 million'',
R-744.com, dated November 29, 2017. Available online at https://r744.com/coca-cola-hfc-free-coolers-count-reaches-2-5-million/.
    \122\ ``NAMA Partners With DOE On More Energy-Efficient Vending
Machines,'' Vending Times, Dec. 16, 2019. Available online at:
https://www.vendingtimes.com/blogs/nama-partners-with-doe-on-more-energy-efficient-vending-machines; Press release, ``NAMA Presses
Congress on ERTC Fix During 2022 Fly-In & Advocacy Summit,'' July
18, 2022. Available online at: https://namanow.org/nama-presses-congress-on-ertc-fix-during-2022-fly-in-advocacy-summit.
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    Comment: EPA received one comment requesting EPA extend the
proposed January 1, 2025, compliance date for vending machines noting
that even the petitioned January 1, 2026, date by AHRI was too early.
The commenter cited barriers to transition including the supply chain
for components, outdated building codes, safety standards and their
respective testing and listing requirements, and the necessity of
satisfactory performance for food industry equipment for maintaining
food safety.
    Response: In consideration of the comment received and the
availability of substitutes for use in this subsector, EPA is
finalizing the January 1, 2025, compliance date for vending machines as
proposed. The Agency recognizes that there are challenges associated
with moving to more flammable refrigerant options, however, the
commenter itself stated that some of the products have

already changed to lower-GWP refrigerants identified by EPA. R-744 has
also been in use for over a decade, signaling that the transition for
vending machines is well underway. Vending machines have smaller charge
sizes than other types of commercial refrigeration equipment and are
therefore less affected by building codes. Relevant standards have
already been updated to allow up to 114 g of A3 refrigerant in vending
machines, with many models already using R-290. Non-flammable
refrigerants like R-744 have also been implemented in models where
flammability may pose greater safety concerns. EPA understands that
NRTLs must test and list new equipment to certify compliance with
various safety standards. However, given that much of the subsector has
already transitioned, fewer models will need to be updated and
certified to comply with restrictions by the date of compliance.
Therefore, for the reasons described, EPA is finalizing the compliance
date as proposed.
e. Cold Storage Warehouses
    Cold storage warehouses are refrigerated facilities used for the
storage of temperature-controlled substances. Refrigeration systems
within cold storage warehouses can be divided into two categories:
central plant systems and packaged systems. Central plants are custom-
built refrigeration systems that are typically used in large
refrigerated warehouses with cooling capacities that range from 20 to
5,000 kW. Central plant systems deliver cool air to the refrigerated
space through evaporators, which are typically suspended from the
ceiling in the refrigerated space. The evaporators are connected
through a piping network to multiple compressors located in a central
machine room, and a condenser, which is typically mounted outside near
the compressor. Central plant systems may have a direct or indirect
(secondary loop) design. Direct systems circulate a primary refrigerant
throughout the refrigerated space. In an indirect system, a primary
refrigerant cools a secondary refrigerant in the machine room, and the
secondary refrigerant is then circulated throughout the refrigerated
space.
    Packaged systems (also known as unitary systems) are self-contained
systems that combine an evaporator, compressor, and condenser in one
frame. Packaged systems are commonly installed on the roof of a
refrigerated warehouse above the air-cooling units that are within the
refrigerated space. The evaporator is located inside the refrigerated
space while the condensing unit, which is usually protected by weather
resistant housing, is located outside. Packaged systems are most
commonly used in small, refrigerated warehouses that have a capacity of
20 to 750 kW.
    In response to the phaseout of ODS under the CAA and the Montreal
Protocol, many cold storage warehouses transitioned from using CFCs to
HCFC-22, and then later from HCFC-22 to HFCs--primarily R-404A and R-
507A, which have GWPs of 3,922 and 3,985, respectively.\123\
Manufacturers transitioned to R-717, as well.
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    \123\ Refrigeration, Air Conditioning, and Heat Pumps Technical
Options Committee 2018 Assessment Report, Technical and Economic
Assessment Panel, UNEP, February 2019. Available at: https://ozone.unep.org/sites/default/files/2019-04/RTOC-assessment-report-2018_0.pdf.
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What restrictions on the use of HFCs is EPA establishing for cold
storage warehouses?
    As proposed, EPA is prohibiting the installation of new cold
storage warehouse systems using HFCs and blends containing HFCs with a
GWP of 150 or greater when the system's refrigerant charge capacity is
equal to or greater than 200 lb. For cold storage warehouse systems
with refrigerant charge capacities less than 200 lb and for the high
temperature side of cascade systems, EPA is establishing a GWP of 300.
In response to comments received on the proposal, EPA is finalizing a
compliance date of January 1, 2026, one year later than the proposed
compliance date of January 1, 2025.
    As with supermarket systems, IPR systems, and remote condensing
units, EPA is distinguishing between larger cold storage warehouse
systems and smaller systems with a refrigerant charge capacity of 200
lb being the dividing line. EPA is also establishing a higher GWP limit
of 300 for the high temperature side of a cascade system, based on
safety standards as discussed in section VI.F.1.a of the preamble.
    For its consideration of availability of substitutes under
subsection (i)(4)(B), EPA identified several substitutes that are
available in place of the substances that EPA is restricting. For
systems with refrigerant charge capacities equal to or greater than 200
lb, these include R-717 vapor compression (GWP 1), R-744 (GWP 1), and
HCFO-1233zd(E) (GWP 4). Another substitute is R-471A (GWP 144), which
SNAP has listed as acceptable for cold storage warehouse use under
Notice 38 (88 FR 61977, September 8, 2023). Additionally, EPA has
proposed to list as acceptable R-454C (GWP 146) for use in larger cold
storage warehouse systems and R-454A (GWP 237) for use in smaller
systems, subject to use conditions. Other low-GWP refrigerants EPA has
proposed acceptable for these systems are HFO-1234yf (GWP 1), HFO-
1234ze(E) (GWP 1), R-457A (GWP 137), and R-516A (GWP 140). (88 FR
33722, May 24, 2023). Newer technologies with smaller charge sizes of
R-717 that are removed from the general public are low-charge packaged
ammonia systems, ammonia/CO2 cascade systems, and ammonia
secondary loop systems.\124\ Given that EPA's evaluation of these
refrigerants is underway, the Agency anticipates additional substitutes
below the GWP limits may be available for use in this subsector in the
future. Several other types of systems that operate using thermodynamic
cycles other than vapor compression such as absorption, evaporative
cooling, desiccant cooling, and Stirling cycle systems can also be used
in this subsector and may be appropriate for meeting the restrictions
finalized.
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    \124\ ICF, 2016. Market Characterization: Fire Suppression,
Commercial Comfort Cooling, Cold Storage, Refrigerated Food
Processing and Dispensing Equipment, and Household Refrigeration
Industries in the United States. Prepared for U.S. EPA. March, 2016.
---------------------------------------------------------------------------

    A significant portion of cold storage warehouses have transitioned
from, or completely avoided, using higher-GWP HFCs. Most cold storage
warehouses in the United States use R-717. ASHRAE designates R-717 as a
lower flammability, higher toxicity (B2L) refrigerant and it is not
used extensively in many other subsectors of the RACHP sector. However,
many users consider R-717 to be a cost-effective option for use in cold
storage warehouses given its long-standing use, lower cost per
kilogram, and energy savings \125\ despite a higher capital cost for
the equipment compared to HFC systems. Certain characteristics of cold
storage warehouses also tend to reduce their proximity to people and
thus the risk of using R-717. For example, because cold storage
warehouses are often large in order to achieve economies of scale and
require a large amount of land use--as opposed to other systems that
might be located on a building roof or a small slab next to the
building--they are typically located away from population centers where
land costs and taxes may be higher. In addition, the transportation of
goods is typically done in large volumes--by truck or train--to reduce
costs, which in turn reduces the workforce needed and the number of
people at the warehouse and, in particular, near the refrigeration
equipment.
---------------------------------------------------------------------------

    \125\ Ibid.
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    Comment: Several commenters generally supported EPA's proposed

GWP limit of 150 for commercial refrigeration equipment with over 200
lb of refrigerant charge; however, many of these commenters recommended
that EPA eliminate or modify the GWP limit of 300 that was proposed for
charge sizes less than 200 lb. Some commenters recommended a 50 lb
charge size threshold and noted this would be consistent with
California's regulations. One group described a 10 lb charge capacity
cutoff as more appropriate than 200 lb and recommended a single GWP
limit of 10 for all charge sizes. A summary of other comments related