Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements Promulgated Under the Technology Transitions Provisions of the American Innovation and Manufacturing Act of 2020

Comment: Commenters that addressed this provision in their comments were generally supportive of the Agency's proposal. Commenters in the semiconductor manufacturing industry agreed with the charge size threshold of 100 pounds or less for SMRE and stated that the proposal correctly recognizes the additional time needed to design, test, qualify, validate, and deploy the type of specialty equipment used in semiconductor manufacturing. Two commenters noted that the proposal appropriately accounts for long qualification cycles and complex supply chain integration that is unique to the industry.

Response: The EPA acknowledges commenters' support for the rationale behind the proposed revisions and is finalizing as proposed.

Comment: One commenter described the impacts if additional time to transition is not provided. This commenter stated there could be supply chain disruptions that could cascade across industries dependent on advanced chips, including automotive, telecommunications, energy production, and defense manufacturing. This commenter further noted that semiconductor manufacturing is uniquely capital-intensive, and even temporary interruptions can reverberate globally and cause shortages and price volatility.

Response: The EPA agrees with the semiconductor manufacturers' concerns, particularly for potential downtime and that such downtime could have impacts on critical industries and national security. Given the information provided on more time to test, qualify, and validate substitutes, the EPA is providing until January 1, 2030, as described above.

Comment: One commenter stated the contribution of SMRE to overall HFC emissions is minimal, estimated at less than one-tenth of one percent of annual U.S. greenhouse gas emissions. Several commenters who were generally opposed to relaxing the requirements of the 2023 Final Rule due to impacts on the environment were opposed to this proposal.

Response: The EPA agrees that any potential impacts on HFC emissions would be minimal. The EPA also notes that the statute directs the Agency to factor in to the extent practicable the factors listed in subsection (i)(4) which includes the availability of substitutes, among other things. Based on the totality of the record for this rulemaking, and in particular the information on alternatives, the Agency has determined that more time is needed for substitutes to be designed, tested, qualified, validated, and deployed.

Comment: Three commenters said that an extension to January 1, 2030, may still be insufficient. Two of these commenters suggested that it may be insufficient for applications between -50 [deg]C and -30 [deg]C. The other commenter recommended an extension until December 31, 2030, to provide regulatory predictability and flexibility noting that the proposed timeline to transition may be too short. This commenter also supported an exemption for this equipment, noting that transition challenges will likely continue to persist past 2030. One commenter noted that even where substitutes may eventually become viable, equipment redesign, testing and qualification processes typically take at least five years from concept to deployment.

Response: The EPA acknowledges that qualification cycles for process refrigeration equipment in the semiconductor manufacturing industry can take a long time. The EPA notes that the submitter of the administrative petition indicated January 1, 2030, as a realistic compliance deadline, and that five semiconductor equipment manufacturers submitted letters in support of the petition. At this time, the EPA does not have any technical information or data that justifies a date other than what the Agency proposed. To the extent additional information is provided that January 1, 2030, may not be sufficient, the EPA will consider revising the compliance date.

Comment: One commenter suggested that the EPA should provide a mechanism to re-evaluate the compliance date in 2028 for very low temperature applications.

Response: The EPA appreciates this comment, but the Agency did not propose and is not finalizing a mechanism to re-evaluate the 2030 compliance date. The Agency will continue to monitor the transition and encourages regulated entities to continue to share information on the development and deployment of alternative refrigerants, including those for low temperature applications. Based on the information and data the EPA currently has, the Agency anticipates this sector will be able to meet the January 1, 2030, compliance date as it will continue its progress on equipment

redesign, testing, and qualification processes.

Comment: One commenter suggested the EPA establish a formal supply chain readiness review in advance of the 2030 deadline.

Response: The EPA did not propose and is not finalizing a formal mechanism to evaluate supply chain readiness in advance of 2030. The Agency will continue to monitor supply chain readiness. Based on the information the EPA currently has, the Agency does not foresee any supply challenges with meeting a 2030 deadline. However, if that changes, the EPA will reevaluate whether the 2030 deadline is achievable.

Comment: Commenters requested that the EPA narrow or expand the scope of equipment subject to this provision. One commenter encouraged the EPA to be clear that this flexibility applies to a narrow subset of equipment that requires extreme-precision projection lenses (e.g., lithography), and not to other chillers and refrigeration systems used in fabrication plants. One commenter suggested that the EPA consider extending the proposal to all industrial process chillers with charge sizes up to 100 pounds, not just those used in SMRE. They stated that a uniform compliance date for these equipment types would be easier for manufacturers and users to administer, given the practical difficulty of identifying end-use applications.

Response: The EPA reaffirms that it is finalizing an extension only for a narrow subset of process refrigeration equipment that requires extreme precision used in the manufacture of semiconductors. Based on the information provided to the EPA, these process chillers and IPR equipment are highly specialized and require time to be qualified, validated, and deployed for use in semiconductor manufacturing. The EPA does not have sufficient technical information and does not consider it necessary to further narrow this provision to a specific subset(s) of semiconductor manufacturing equipment, such as projection lenses. The EPA finds that a delineation of SMRE with a charge size of 100 pounds or less is appropriate given the shared challenges of this equipment to be qualified, validated, and deployed for use.

The EPA did not propose and is not finalizing an exemption for all IPR and Chillers for IPR equipment with a charge size of 100 pounds or less except where such equipment is used for semiconductor manufacturing. The EPA acknowledges that IPR and Chillers for IPR are used in a range of applications. The EPA understands from the petitioner and from supporting information that semiconductor manufacturing use of IPR and Chillers for IPR equipment have unique challenges.

As described in this section IV.B, section III.B of this preamble, and in the October 2025 Proposal, the Agency received and considered new information after the issuance of the 2023 Final Rule specifically about semiconductor manufacturing. The Agency did not receive information concerning the limit or compliance for IPR and Chillers for IPR equipment containing 100 pounds or less more generally. Further, the EPA does not have information that would support the conclusion that it would be impossible to differentiate semiconductor manufacturers from other users of IPR or Chillers for IPR equipment.

Comment: Two commenters supported the EPA's clarification in the proposal that “the lowest temperature at which equipment is designed to operate determines whether it is subject to use restrictions.”

Response: The EPA acknowledges these commenters' support. The EPA reiterates that IPR and Chillers for IPR used in the semiconductor manufacturing industry may operate at one temperature while being designed to reach lower temperatures. As stated in section III.A of this preamble, the lowest temperature at which equipment is designed to operate determines whether it is subject to use restrictions.

Comment: Some commenters supported the proposed graduated schedule to provide time for manufacturers and contractors to adapt, train technicians, develop safety protocols, and update building codes. One commenter also claimed that the original transition dates would disproportionately affect independent grocers, who would bear additional costs and pass them on to consumers. Another commenter stated that the phased approach benefits small and/or rural supermarkets with reasonable capital planning, coordinated vendor engagement, and long-term equipment investment, all of which provide critical flexibility for independent grocers.

Another commenter supported the limit of 1,400 for retail food applications to allow industry to organically transition to A2L refrigerants. According to one commenter, industry experts estimate that a minimum of 2-3 years is required after code updates before safe implementation can begin. Another commenter stated that the extended compliance date to 2032 allows code officials to put the appropriate Life Safety codes in place before introducing lower flammability refrigerants. One commenter agreed that supermarket systems required a later start date compared to remote condensing units in the phase-in approach, given they are more complex. The commenter also stated that the revisions to the compliance schedule provide immediate relief for stores needing to install new systems while providing a workable pathway to the 2023 Technology Transition Rule's targets.

Response: The EPA acknowledges commenters' support for the proposed graduated schedule of limits for supermarket systems. The Agency understands the need for additional flexibility for supermarket systems in the near term, and acknowledges the complexity involved with designing and installing such systems and potential challenges with building code adoption, particularly at the local level. The EPA understands that many factors may be considered by store owners and operators when selecting a supermarket system, including choice of refrigerant. The EPA assessed the additional flexibility of providing the interim limit of 1,400 beginning on January 1, 2027, as adding for an additional set of refrigerants to be available for such consideration and aligns with the comments the EPA received. Commenters pointed to the need for more flexibility when selecting a refrigerant for their supermarket systems as well as allowing additional time for wider adoption of building codes to allow even more options, including A2L refrigerants.

Delaying the compliance date to 2032 for the limit of 150 or 300, as applicable, provides an additional five years for retailers to continue to install systems using HFC refrigerants below the 1,400 limit, which provides sufficient time for any current concerns identified by commenters to be resolved. The EPA is aware that there are already available options in use for supermarket systems that meet the requirements in the 2023 Final Rule; however, based on the information received ahead of the proposed changes and during the comment period, the EPA concludes that there are challenges related to deploying such systems in certain geographical areas of the United States that result in lag which is addressed by this rule. The Agency describes and responds to these comments and concerns, including building codes,

energy efficiency, and more, in later responses in this section and in the Response to Comments found in the docket for this rule.

Comment: Some commenters opposed the sector-wide delay and interim limit for supermarket systems and stated that the requirements established in the 2023 Final Rule should be maintained. One commenter stated that weakening the rules for retail food systems will confuse the market, penalize early adopters, reward laggards, and lock in more environmentally harmful refrigerants for decades to come. Another commenter stated that California state regulations adopted a 150 limit for commercial and industrial refrigeration that have been enforced since 2022. They noted that through extensive stakeholder outreach, the retail food industry expressed desire to have future-proof solutions rather than interim solutions that would be more costly.

One commenter stated that EPA proposed these delays and increases in limits without having necessary information available, as evidenced by the Agency seeking multiple types of information in the proposed rule, and thus the proposed timelines and limits are not supported by technical information. One commenter stated that maintaining the previous compliance schedule preserves the United States as an early mover promoting American innovation and technology.

Delays in the compliance schedule would re-open the domestic market to outdated technologies and give foreign manufacturers a competitive advantage. Another commenter stated that delaying implementation until 2032 would negate potential reductions in emissions of refrigerants, and the delay goes against the AIM Act's requirement for a rapid transition to alternatives.

Response: The EPA disagrees with the commenters' opposition to the proposal and generally disagrees with these comments related to retaining the limits and compliance dates for supermarket systems. The EPA is finalizing a graduated schedule approach which retains as a first step the January 1, 2027, compliance date, consistent with the compliance date in the 2023 Final Rule for supermarket systems. The Agency reiterates that it is aware that some retailers are able to use refrigerants below the limits set in the 2023 Final Rule already; however, the Agency concludes for reasons stated elsewhere in this section, there are supermarkets that will benefit from the flexibility the EPA is creating by moving to the graduated schedule. While the interim limit is in effect from January 1, 2027, until January 1, 2032, store owner and operators would have options for refrigerants that are above the 150 and 300 limits and below the 1,400 limit, including but not limited to R-448A, R-449A, and R-513A.116 117 R-448A, R- 449A, and R-513A are classified under ASHRAE as A1 refrigerants, meaning they are non-flammable and do not have the same installation challenges as refrigerants with A2, A2L, and A3 flammability characteristics.\118\ Thus, this offers retailers the opportunity to use a refrigerant with similar flammability and pressure ratings to what the industry may have historically used. However, the EPA notes that there will be other reasons for retailers to move to refrigerants with 150 or 300 limits ahead of 2032.

\116\ R-448A is a blend of three HFCs and two HFOs. R-449A is a blend of three HFCs and one HFO. R-513A is a blend of one HFC and one HFO.

\117\ See trade association's letter to the EPA, dated February 11, 2025, in the docket for this action, and GreenChill “Partnership Accomplishments” at https://www.epa.gov/greenchill/partnership-accomplishments.

\118\ ANSI/ASHRAE Standard 34-2024 Designation and Safety Classification of Refrigerants.

For example, the HFC phasedown and particularly the 2029 HFC reduction step could impact price and availability of R-448A, R-449A, R-513A, and other HFC or HFC refrigerant blends. There will also be time for the supermarket industry to become more familiar with CO2 systems. Therefore, some retailers may choose to use a substitute that is below 150 or 300, as applicable, prior to the compliance date of January 1, 2032. The EPA disagrees that finalizing the graduated schedule would go against the goals of the AIM Act for a rapid transition to alternatives. While subsection (e) of the AIM Act establishes the HFC phasedown schedule, the AIM Act does not prescribe a defined schedule for the transition to alternatives for any specific sectors and subsectors.

The EPA understands that a delay in the compliance date for the limits of 150 or 300, as applicable, could result in additional use of HFCs in this subsector; however, the EPA does not agree that this would have a significant impact on the continued use of legacy HFC systems. The interim limit of 1,400 beginning on January 1, 2027, means that legacy HFC refrigerant blends, such as R-404A, R-407A, and R-507A, would not be installed in new supermarket systems starting January 1, 2027, and instead only those that meet the interim limit could be used. The EPA considers the 2027 interim limit to be significant, and it is important that it occurs ahead of the 2029 phasedown step. Further, the EPA disagrees that the graduated schedule approach finalized in this rulemaking would discourage American innovation and reward foreign entities.

By providing the interim limit for five years, the EPA is providing additional time for U.S. companies to further develop, design, and distribute technologies for supermarket systems that use refrigerants below the 2032 limits that meet the needs of particular stores. Retailers also still have the option to adopt technologies that use refrigerants below the 150 or 300 limit sooner than the 2032 compliance date in this rule.

Comment: Some commenters suggested alternate compliance dates or limits compared to the proposal for supermarket systems. Commenters requested the limit align with the next stepdown date of the allocation phasedown schedule and should be adjusted to 2029 for supermarket systems. One commenter stated that instituting the interim limit of 1,400 followed by a limit of 150 or 300, as applicable, beginning in 2029 would still allow flexibility in the near term and would accelerate retrofits or replacements to available substitutes. Another commenter stated that a shorter extension to 2029 would avoid possible long-term cost increases for regulated refrigerants.

Some commenters opposed the proposed delays and interim limits but said if the EPA were to finalize a delayed compliance date for the limits of 150 or 300, as applicable, it should be no later than January 1, 2029. One commenter stated that a two-year extension would be needed for supermarket systems due to constraints on the use of A2L refrigerants that meet the limits of 150 or 300, as applicable.

Response: The EPA disagrees with these commenters' assertion that EPA must or should align the 150 or 300 limit, as applicable, with the 2029 phasedown step. As a general matter, the EPA does not agree that compliance dates established under the Technology Transitions subsection of the AIM Act need to align with the dates Congress established for the phasedown schedule under AIM Act subsection (e). These are two distinct subsections, each with their own direction and authority. The EPA concludes that only providing an additional two years would provide limited flexibility to retailers and would not be sufficient. As described elsewhere in comment responses in this section, the interim limit and delay in the final limit for the subsector, as finalized, provide sufficient flexibility in refrigerant choice and time for industry nationwide to fully prepare

with the 150 or 300 limits, as applicable. For example, the additional five years will allow OEMs more time to develop equipment meeting the needs of all their customers and to establish supply chains to distribute such equipment throughout the United States.

Comment: Commenters stated that the proposed delay in compliance dates for supermarket systems would conflict with the AIM Act's requirement for phasing down production of HFCs, and there will be a much greater demand for HFCs by 2032 than allowed production can support. One commenter stated that delays in the compliance dates and limits would continue to elevate demand for new systems as the phasedown gets tighter, which would draw down HFC inventories and push demand above supply by 2030. One commenter stated that the delays to the requirements would increase near-term HFC demand and misalign the AIM Act's intended ability to guide an orderly transition. Another commenter expressed concern that extending use of legacy refrigerants in the retail food sectors will significantly add to demand, draw down existing stocks of HFCs, and shift the allowance pool away from HFCs that meet lower limits towards unnecessary legacy refrigerants.

Another commenter stated that raising the limit for refrigerants in commercial refrigeration systems would increase HFC consumption, given high average leak rates in this sector, and would contradict the overall phasedown of HFCs under the AIM Act. One commenter stated that an extension to 2029 for supermarket systems would not materially impact a potential shortage of HFCs in 2029, while delaying to 2032 could have such adverse effects and since supermarkets would have a longer period of time to use legacy HFC systems.

Some commenters noted that the delays and increased demand will cause prices to increase for HFCs in the retail food sector. One commenter expressed warning that the delays may come with broader negative impacts to the entire consumer base in the near term, including refrigerant shortages as soon as 2028. Another commenter stated the increased costs for maintenance and refrigerants in the retail food sector would be passed on to American consumers. Another commenter stated that any shortfall between available supply and required servicing demand is likely to cause higher prices for all end users.

One commenter anticipates that a refrigerant shortage may occur starting in 2027 if compliance dates and limits are relaxed. They commented that such delays and relaxed limits will further cause shortages beyond the commercial refrigeration sector and would affect other sectors such as residential and commercial air conditioning, leading to increased servicing costs for consumers.

Response: The EPA disagrees with commenters that assert that delaying the 2023 Final Rule limits of 150 or 300, as applicable, for supermarket systems by an additional five years would adversely affect the overall phasedown of HFCs under the AIM Act. As noted previously, the phasedown schedule Congress established in subsection (e) of the AIM Act is wholly separate from the Technology Transitions provisions in subsection (i). The EPA acknowledges that continued installation of new HFC supermarket systems inherently results in future demand for HFCs to service such systems.

The EPA disagrees that it is necessary or appropriate to choose compliance dates under subsection (i) based on the phasedown schedule that align the limits for supermarket systems with the next phasedown step are a hook upon which to establish a date. Congress' direction under subsection (i) is to the extent practicable, factor in “the remaining phase-down period for regulated substances,” among other factors. In addition, the phasedown itself is a separate and key market driver for all refrigerant users. The EPA has considered the remaining phasedown period as well as the other factors listed in subsection (i)(4) and factored them in to the extent practicable, consistent with Congressional direction.

Comment: One commenter suggested adjusting the interim limits to 750 rather than 1,400 and reduce to 150 or 300 in 2032. The commenter stated this aligns more closely with currently available technology.

Response: The EPA disagrees that an interim limit of 750 would be appropriate for the supermarket systems subsector. The EPA acknowledges that to a large extent, in the 2023 Final Rule, the Agency used a few numerical limits, such as 150 or 700. However, the EPA did not use 750 in any sector or subsector and, moreover, it made its decisions based on information relevant specifically to each sector or subsector. As described in other comment responses in this section, two HFC refrigerant blends (i.e., R-448A and R-449A) are currently being used in new supermarket system installations and are below the 1,400 limit; however, these substitutes are above a limit of 750. While R-513A was also mentioned as a refrigerant option for this subsector and could meet a 750 limit, such a limit would not allow R-448A or R-449A and would limit the flexibility in refrigerant choice for supermarket systems during the interim period.

Comment: Commenters stated that there are substitutes and technologies available for supermarket systems. One commenter noted that the record does not support claims that substitutes are not available, or the building codes require sector-wide delays. One commenter stated that many distributors report that complete supermarket refrigeration solutions that meet the 150 or 300 limit are on the market and used in the installation of supermarket systems in various regions across the country, including the southern United States. Other commenters stated that there are multiple Significant New Alternatives Policy (SNAP) listings for available substitutes for supermarket systems with safety standards incorporating Underwriters Laboratories (UL) 60335-2-89 and ASHRAE 15-2022.

Response: As stated previously, the EPA understands that there are challenges with transitioning to substitutes and technologies in certain cases even if there are substitutes available for supermarket systems that may be able to comply with the 2023 Final Rule compliance timelines and limits. The EPA indicated in the 2023 Final Rule that several substitutes, including CO2 and some A1 and A2L HFC blends, were available or would soon be available in time for the supermarket systems subsector compliance date of 2027.\119\ The EPA finalized SNAP Rule 26 and listed seven A2L substitutes as acceptable, subject to use conditions, for use in new supermarket systems.\120\ Two are non-HFC refrigerants (HFO-1234yf and HFO-1234ze(E)) and thus are not subject to subsection (i) rules. Five are HFC/HFO blends (R-457A, R-516A, R-454C, R-455A, and R-454A), which, except for R-454A, satisfy the 150 limit for installation in new supermarket systems that have a charge size of 200 pounds or more. All of these refrigerants may also be installed in such systems that have a charge size less than 200 pounds, or as part of the high temperature side of a cascade system.

\119\ See 88 FR 73098 (October 24, 2023).

\120\ See 89 FR 50410 (June 13, 2024).

While increasing the number of refrigerants listed as acceptable under the SNAP program can provide more options, more time is needed for chemical suppliers to provide them in sufficient quantities, for equipment manufacturers to develop equipment for these substitutes, and for this equipment

to be incorporated into new supermarket system designs and be deployed. The EPA is seeking to avoid supply chain issues similar to those that arose with the deployment of the new refrigerant blend, R-454B, in the residential and light commercial AC/HP subsector. In that situation, while the refrigerant was being manufactured in sufficient quantities, it was not available in field for equipment installation and servicing.\121\

\121\ See Memorandum--Overview of R-454B Refrigerant Shortage and Current Status, in the docket for this action.

Extending the compliance date for this subsector to 2032 for the limits of 150 or 300, as applicable, preserves optionality and flexibility in the interim period and allows market pressure and the advantages of the new refrigerants to drive the continued transition to identified substitutes as the commercial availability of newer substitutes matures. The EPA thus expects that refrigerant options below the 150 or 300 limits, as applicable, including those identified as available substitutes for supermarket systems in the 2023 Final Rule and those listed in SNAP Rule 26 for this subsector, will become more widely available for this subsector by January 1, 2032.

Comment: One commenter stated that the EPA contradicted itself in asserting that there are too few refrigerants available that meet the 150 or 300 limit since the EPA already stated there are available substitutes in the 2023 Final Rule. The commenter further stated that any one of the available substitutes identified by the EPA would be enough to support the existing rule (i.e., the 2023 Final Rule). Another commenter further stated that the EPA's request for more information on alternatives was unnecessary because availability of substitutes was already demonstrated in the 2023 Final Rule, and the use of alternatives continues to grow. One commenter stated that the statutory test for availability of alternatives is when one is available, and there is no requirement for an arbitrary number of multiple substitutes to be available.

Response: As described in the prior comment response, the EPA agrees that there are substitutes available for the supermarket systems subsector. However, the EPA disagrees with the comment that there is a statutory test indicating that the availability of a single substitute, or a number of multiple substitutes, demands a particular outcome. The availability of substitutes is one factor the EPA considers when promulgating rulemaking under subsection (i) of the AIM Act. Subsection (i) directs the EPA to factor in, to the extent practicable, more than a half dozen considerations, some or all of which may be applicable for a particular subsector or substitute. Furthermore, the breadth of end uses in a subsector may require multiple substitutes, which the EPA may consider to determine that substitutes are available in that subsector.

Comment: Commenters provided examples of substitutes, primarily CO2, in use today in supermarket systems. One commenter provided evidence that large and small retail food facilities throughout California have been effectively using CO2 and other refrigerants that meet the 150 or 300 limit. Another commenter provided multiple examples of large and small grocery stores and chains that have made progress and commitments to transition to CO2 and refrigerants that meet the 150 or 300 limit in their stores. One commenter stated that in their research, 2,800 retail food stores in the United States have transitioned to equipment using CO2 as of the end of 2023. Some commenters stated that approximately 4,100 stores were using transcritical CO2 systems as of December 2024. One commenter provided data on the numbers of stores by certain companies that are already using CO2 in supermarket systems, including in larger and smaller format stores. Other commenters stated that the use of CO2 in supermarket systems increased by over 40-50 percent from 2023 to 2024. Another commenter stated that CO2 adoption in supermarket systems is projected to grow from 5.8 percent of retail food stores today to 22 percent by 2028.

Another commenter stated that CO2 systems are proven and widely used by many retailers and that components such as compressors, valves, controls, etc. are available from a diversified supply chain. The commenter noted that there are technician training programs in place nationwide to support adoption. One commenter stated that CO2 is already being used in supermarket systems, even in warmer climates, and year-to-date manufacturing of equipment that meets the 150 or 300 limit has increased dramatically. The commenter further stated that they use multiple available substitutes for commercial refrigeration categories in the proposal in their standard product offerings, including R-454A, R-454C, R-455A, and CO2. They commented that they provide a product line that is currently manufactured and sold that meets the 150 or 300 limits, including refrigerant rack systems.

Response: The EPA acknowledges the examples provided by commenters of equipment that is currently available that meets the 150 or 300 limit, as applicable, for supermarket systems, and which aligns with the EPA's understanding of available equipment described in the prior comment response in this section. As stated previously, nothing in this rule would prevent retailers from transitioning to a supermarket system that would comply with the 150 or 300 limits. As commenters stated, there are many such examples, and the EPA expects that there will be retailers who might opt for such refrigerants prior to January 1, 2032, if they are installing a new supermarket system. The EPA anticipates that at least 20% of the market will transition to a supermarket system below the limits of 150 or 300, as applicable, well before the compliance date on January 1, 2032.\122\ The EPA is aware of several major supermarket chains that have made announcements indicating such transitions and thus the EPA assumes those companies will not take advantage of the additional flexibility afforded by this final rule. The EPA anticipates the additional time for compliance will allow these systems to continue to be improved and have additional widespread availability across the country.

\122\ See Economic and Environmental Impacts Memo in the docket for this action.

As stated in prior responses, while there are supermarket systems available with substitutes below the limit of 150 or 300, as applicable, the graduated schedule in this rule is still necessary to provide flexibility for choice of refrigerant until these limits are effective in 2032. The availability of substitutes is just one factor among many that the EPA considers for establishing the limits in the supermarket systems subsector. Supermarket systems are not off-the- shelf systems and are configured with many different components to meet the specific needs of the store in which it will be used. The graduated schedule considers this as some retailers may transition to these available substitutes sooner than January 1, 2032, while others may require additional flexibility.

Comment: Some commenters provided information on the potential energy efficiency benefits of certain refrigerants in supermarket systems. One commenter disagreed with the EPA's claims that installing CO2 in warmer climates may be less energy efficient; the commenter provided an example of a grocer who announced

they would transition to CO2 for all stores, including those in warmer climates. One commenter also stated that CO2 systems can provide energy efficiency benefits, even in warmer climates. One commenter stated that properly configured CO2 and A2L systems use similar or less energy compared to older HFC technologies. Another commenter stated that A2L blends like R-454C match capacity within 3-5 percent and improve energy efficiency as compared to R-404A for supermarket systems.

Response: The EPA acknowledges that some store owners and operators have experienced energy-efficiency benefits when installing supermarket systems with newer refrigerants. Retailers may select supermarket systems with a particular refrigerant for a number of reasons, including the overall energy efficiency of the system. However, retailers may also factor in other considerations such as capital and operating costs, required maintenance of a system, availability of technicians trained to use substitutes, and geographic location of the store. New supermarket systems using CO2 have been installed at an increasing rate in recent years, and it is expected this trend will continue. As the EPA understands, many installations of CO2 systems have been in colder climates, where existing technology can provide energy efficiency benefits and overall lower cost of ownership throughout the life of the system. There have been installations in warmer climates as well; however, the EPA does not have sufficient information that would allow the Agency to tie a certain energy cost or savings to a certain climate. Further, retailers who choose to install a supermarket system with CO2 or an A2L blend must also consider other factors such as available technicians to install and service the system. It is likely that more technicians are available in areas of the country where CO2 supermarket systems have already been deployed, potentially limiting the availability of technicians on a regional basis at this time.

Delaying the compliance date for limits of 150 or 300 for supermarket systems will allow sufficient time for CO2 technologies to be improved and made more efficient nationwide, as well as provide time for more technicians to be trained and familiar with these types of systems.

Comment: Commenters provided information and comments on the challenges of availability and using substitutes for supermarket systems. One commenter stated that many refrigerants below the 150 or 300 limit are either unavailable or withdrawn from the market and that equipment manufacturers have not yet scaled to demand. One commenter noted that they have experienced issues deploying A2L refrigeration systems, as manufacturers currently only offer a handful of A2L systems and most are small remote condensing units that are not suitable for large grocery stores. Another commenter stated that A2L refrigerants (e.g., R-454A, R-454C) remain prohibited under local building codes that are more prohibitive than the state codes; and propane has a charge size limit per circuit that requires dozens of self-contained systems per supermarket, which is inefficient and space-intensive. One commenter stated that even where A2L equipment is installed, many installation companies are having issues with sourcing A2L refrigerants in a reliable or timely manner. Conversely, another commenter stated that HFOs, which are components in certain A2L refrigerant blends, are ready to supply A2L refrigerants for use in supermarket systems; however, supermarket systems (i.e., rack systems) using these refrigerants may require more time for development and building codes may need more time for these systems to use A2L refrigerants.

Other commenters stated that CO2 systems pose numerous challenges in warmer climates, and such systems are only efficient in colder climates where they can be adequately cooled by ambient air. One commenter stated that CO2 systems are unreliable and only a limited number of systems exist which require additional controls to mitigate energy inefficiency. The commenter also pointed out that there are additional safety and practical concerns with using alternatives, including potential generation of hydrogen fluoride gas if an A2L ignites, energy demand for CO2 systems compared to HFC systems, and a lack of trained technicians. One commenter stated that there are only a handful of substitutes available for supermarket systems, and each has certain challenges. They state that CO2 systems consume 20 percent more energy in southeastern states, have higher capital costs, and there are a limited number of qualified technicians available.

Response: The EPA acknowledges that there are currently available substitutes for supermarket systems; however, the EPA has previously indicated that challenges remain that could prevent transition in accordance with the 2023 Final Rule. As stated previously in a comment response in this section, the EPA also indicated in the 2023 Final Rule that several substitutes, including CO2 and some A1 and A2L HFC blends were available or would be available in time for the compliance date in that rule. Further, the EPA received comments providing examples of stores currently using and planning to use substitute refrigerants meeting the 150 or 300 limits, as applicable, in their supermarket systems. While these substitutes are available, the challenges with some substitutes that often are specific to regions of the United States, may be related to availability of equipment, installation and operation of equipment on a regional basis, design of complex systems, availability of properly trained technicians, and needed building code updates.

Providing an interim limit of 1,400 for five years will provide additional flexibility and options of refrigerant choice when installing a new supermarket system. The EPA understands that some retailers may need this flexibility where the challenges may be too cumbersome to use an available substitute that meets the 150 or 300 limit in 2027. As stated above in this section, the interim limit of 1,400 allows for certain common HFC blend refrigerants (e.g., R-448A, R-449A, R-513A) in supermarket systems to be used in new installations until the limits of 150 or 300, as applicable, take effect on January 1, 2032. Retailers have been using R-448A, R-449A, and R-513A in recent years and technicians are familiar with and trained to work on equipment using these refrigerants.

Delaying the compliance date for the 150 or 300 limits, as applicable, for supermarket systems to January 1, 2032, provides sufficient time for industry to prepare for these limits for new installations of supermarket systems. The additional five years will provide additional time for more technicians to be trained on supermarket systems using compliant refrigerants. For example, supermarket systems that use CO2 as a refrigerant operate at high pressures, and technicians will need to be trained to properly and safely maintain these systems. As noted, many technicians across the country may be qualified to service systems using refrigerants meeting the 150 or 300 limits; however, they may be more regionally concentrated in areas of the country where such supermarket systems have had higher adoption rates over recent years. The EPA expects that as more supermarket systems are installed across the country in all regions that are compliant with the 150 or 300 limits, technicians will likewise adapt and become qualified and trained to maintain these systems.

The EPA also acknowledges that there may be certain challenges for supermarket systems that use CO2 based on where the store is located regionally. Particularly, commenters noted that CO2 supermarket systems are less efficient in warmer climates where they cannot take advantage of cooling from ambient conditions. The EPA understands that current technologies may present such challenges; however, as noted in a prior response, there have been installations of CO2 in warmer climates. Other comments submitted on the proposed rule provided examples where CO2 supermarket systems have been installed across the country in various regions and have proven to be at least as efficient as legacy HFC systems. Further, other commenters noted commitments from retailers to continue with new installations of CO2 systems in new stores across the country. Nonetheless, the EPA acknowledges that challenges and opportunities may vary in independent cases, as supermarket systems are large and complex. As such, delaying the compliance date for limits of 150 or 300 in supermarket systems will provide sufficient time for innovation in supermarket systems using CO2. The EPA anticipates that technologies will continue to improve and provide equipment and designs that will operate efficiently in any region of the country.

In addition to CO2 as a choice of refrigerant in supermarket systems, the EPA recognizes that there are additional substitutes available that are classified as A2L. Commenters described challenges with potential safety concerns and building code updates preventing wide-scale adoption of supermarket systems with A2L refrigerants. Regarding the toxicity of breakdown products such as hydrogen fluoride, the EPA's SNAP program considers potential impacts of breakdown products, including hydrogen fluoride upon combustion. The EPA also notes that HFCs mixed with compressor oil also can be flammable at high enough temperatures, and thus, generation of hydrogen fluoride is not unique to A2L refrigerants. The EPA discusses comments related to building codes and provides a more detailed response later in this section. Building code updates are rapidly occurring and underway in nearly all states with processes in place to use A2Ls where codes have not been fully updated. While this is the case, there may be challenges or time-consuming approval processes for installations of supermarket systems with large charge sizes in some jurisdictions. Thus, delaying the compliance dates for limits of 150 or 300 in supermarket systems would allow additional time for more uniform adoption of updated building codes across the country, including in local jurisdictions.

Comment: One commenter stated that the initial start-up costs of CO2 systems have dropped considerably in the last five years. Another commenter also stated that CO2 technologies have advanced significantly in recent years, resulting in lower sustained costs as initial costs decrease with increased adoption. The commenter also stated that A2L systems have already been developed for the 2026 and 2027 compliance dates, and they are expected to be comparable in cost to HFC systems. Another commenter stated that ultra- low GWP refrigerants provide cost savings, including reduced operating costs through greater energy efficiency.

Response: The EPA appreciates comments provided on the costs of supermarket systems installed with substitute refrigerants. The EPA agrees that with increased adoption of such systems, initial costs would be expected to decrease, although the rate and amount of the decrease in costs is uncertain and the EPA has not assumed declining capital or operating costs over time for purposes of the Economic and Environmental Impacts Memo. The EPA also acknowledges that in some cases, there may be energy efficiency benefits with supermarkets systems using certain refrigerants. The EPA further discusses these considerations in other responses in this section.

Comment: Some commenters stated that CO2 systems carry higher operating costs than HFC refrigerants due to complexity, inefficiency, and higher leak rates. Another commenter stated that the current compliance schedules would result in exorbitant compliance costs as a result of the barriers for HFC alternative refrigerants and technologies, including higher capital costs and increased costs to consumers. The commenter stated that grocery stores have very slim profit margins (about an average of 1.7% annually), and this low margin makes it challenging to absorb higher capital costs. Another commenter stated that most CO2 installations for supermarkets occur when a new store is being built or a major renovation is being conducted. They further commented that beyond costs and energy use, other issues reported with CO2 systems include lack of consistent supply of refrigerant-grade CO2, a need for specially trained technicians, and loss of charge resulting in food safety challenges. One commenter stated that, particularly for small- town stores, replacement of refrigeration systems under the limit established in the 2023 Final Rule would cost double normal replacement costs and would result in store closings that would displace employees and create food deserts. Another commenter stated that CO2 gas prices have increased significantly in recent years and that CO2 systems are more costly at a 30.5 percent premium. They further commented that one analysis found CO2 systems consume 20 percent more energy than synthetic refrigerant systems and the total cost of ownership for an average-sized store would be $1.1 million more than an HFC system.

Response: The EPA appreciates the challenges supermarkets face when installing and operating supermarket systems with refrigerants that meet the 150 or 300 limits on the timelines in the 2023 Final Rule. This is particularly relevant when installing new systems, when there are a variety of factors to assess. For example, supermarkets and grocery stores--and the retailers that run them--range in size and are located in differing geographic regions and weather climates. In addition, the EPA appreciates that the low profit margins that supermarkets experience cause certain technologies to be cost prohibitive on the timelines in the 2023 Final Rule. Supermarket and grocery store retailers may choose one option over another due to capital costs, energy efficiency, technician availability, or other considerations.

The graduated schedule of limits established in this rule will mitigate these concerns by allowing for supermarket systems to be installed with an interim limit of 1,400 before the 150 or 300 limits are effective on January 1, 2032. The EPA anticipates that there will be some store owners or operators that will move faster than the compliance timelines and install supermarket systems that meet the 150 or 300 limits earlier than 2032. The EPA anticipates that this will lead to further innovation of such systems and cause prices to decrease as adoption of these systems increases and become more widespread across the country.

Comment: Commenters state that building code updates have occurred rapidly across the country to allow the use of A2L refrigerants. They note that 49 states have recognized A2L use either through code updates, legislation, or interpretive letter; only Florida and Louisiana are still completing their process, but they remain on timelines to allow compliance with timelines established in the 2023 Final Rule. One commenter stated that home rule

structures do not alter the assessment of building code readiness, as statewide adoption of the 2024 model codes or equivalent statutory authorization does not default to a prohibition on A2L use.

Some commenters stated that EPA has not identified any local jurisdiction that has made its building codes stricter than its state's building code by banning A2L refrigerants and they are not aware of any such cases. One commenter specifically noted that they are not aware of any instances of local building codes in California preventing or delaying installation of systems with A2L or A3 refrigerants. Another commenter stated that a majority of states have legislation that prevent local building codes from restricting A2L and A3 refrigerants approved by the SNAP program. One commenter stated that all model codes in the United States, including the International Building Code (IBC), International Mechanical Code (IMC), International Existing Building Code (IEBC), and Uniform Mechanical Code (UMC), contain provisions that authorize authorities having jurisdiction (AHJs) to approve alternate materials, design, methods, and equipment when an applicant demonstrates the proposed system meets the intent of the code and provides equivalent safety. The provisions were created to ensure code adoption lag does not become a barrier to new technology. The commenter further noted that where an official denies a request, the international codes require that a local board of appeals be available to review the decision. One commenter stated that local authorities can and routinely do issue interim approval letters allowing the installation of equipment that complies with UL 60335-2-40, UL 60335-2- 89, and ASHRAE 15. The commenter also noted that CO2 systems are not subject to A2L or flammability code restrictions and have long been permitted under all model building codes; thus, the claimed building code barriers do not apply to CO2 systems and do not justify a deferral of the Technology Transitions compliance schedule. Another commenter stated that updates to UL 60335-2-24 allow for expanded charge sizes of A3 refrigerants in commercial and industrial applications, while incorporating safety protocols to mitigate flammability risks. They note that 3.8 million self-contained units that use propane have been installed in the United States. One commenter noted that industry has extensive resources to support small and large owners and operators of A2L technology and other resources to alternate methods of adoption where building codes are not yet fully updated.

Other commenters stated that the revised compliance schedule would allow local jurisdictions the time necessary to adopt local building and fire safety codes to allow the deployment of refrigerants that meet the 150 or 300 limit for supermarket systems. One commenter noted that in multiple states, local codes prohibit the use of A2Ls because of safety concerns. Another commenter stated that in Texas, each AHJ adopts local amendments to fire codes that are established at the national level by the National Fire Protection Association (NFPA) and the International Fire Code (IFC) and that manufacturers may be confusing the IMC standards for A2Ls with Fire and Life Safety codes under NFPA and IFC. The commenter noted that IFC and IMC have standards at this time while NFPA has no codes for installing equipment with A2Ls, and model standards may not be available until the 2030 code cycle. Another commenter stated that thirty states allow local jurisdictions to adopt their own building codes, which may prevent introduction of A2Ls. The commenter also noted that other state laws may prevent certain systems and provided Nevada as an example where there are restrictions on water usage that would essentially prohibit water-dependent cooling systems. One commenter stated that while legislation may be in place to use A2Ls, contractors still need to obtain permits to install A2L equipment. They also commented that while AHJs have the authority to allow more updated building codes where they are not yet adopted, the process takes time and costs for contractors and equipment owners to educate an AHJ. One commenter noted that the delays in compliance dates would allow for the continued updating of safety standards based on feedback submitted by manufacturers.

Response: The EPA appreciates the comments and information provided on the status of updated building codes across the country and acknowledges that rapid adoption has taken place. The EPA understands that not all local jurisdictions have adopted updated building codes to allow complete deployment of A2L refrigerants in supermarket systems nationwide. The EPA agrees that there are substitutes available that have been approved by the SNAP program, and where building codes have not yet been updated, there may be legislation in place to allow A2Ls or processes to approve equipment using A2Ls. While local building codes may not fully prevent adoption of A2L refrigerants due to these processes and legislation, the processes in place to allow A2L technologies may be time-consuming and challenging for those installing supermarket systems. Where the most up-to-date building codes have yet to be adopted, local jurisdictions or AHJs may have concerns or lack the in-depth knowledge to fully review a permit application for installing a complex supermarket system that uses an A2L refrigerant.

The EPA agrees that CO2 used in supermarket systems would not face the same challenges with building codes since it is an A1 refrigerant. As discussed in other responses in this section, there may be other challenges or potential opportunities related to using CO2 in supermarket systems. For example, the EPA understands that there are challenges with installing CO2 supermarket systems in certain regions of the country. Further, supermarket systems using CO2 operate at high pressures and require technicians that are trained to service and maintain these systems.

While adoption of building code updates continues rapidly across the country, the EPA acknowledges the challenges that are present for A2L refrigerants in supermarket systems. Several commenters have noted that building code updates would be in place in time for the compliance schedule prescribed in the 2023 Final Rule. However, as described above, building code updates have not been solidified across all local jurisdictions. This could create confusion or challenges for store owners and operators who would select an A2L refrigerant for their supermarket system and the local jurisdiction is not prepared to review such a permit application. Thus, the Agency finds that additional time is required for local jurisdictions to continue to adopt updated building codes. In the case that typical code cycles may take longer than the compliance dates finalized in this rule, local jurisdictions will have additional time to review updated codes to allow approval processes to be more efficient.

The EPA anticipates that by January 1, 2032, any remaining building code issues would be fully resolved, given that the UL safety standard updates addressing these refrigerants will have been published for a sufficient amount of time prior.\123\ Information provided

by food retailers indicates that updating model codes at a local level could take up to eight years.\124\ Thus, the graduated schedule finalized in this rule provides sufficient additional time for building code updates across the country and addresses concerns raised in comments. It provides flexibility in the interim period to use certain refrigerants such as R-448A, R-449A, and R-513A which are A1 refrigerants and do not face building code challenges for installations. The five-year period of the interim limit will provide time to continue to use these A1 HFC/HFO blends while allowing building code updates to continue to progress.

\123\ See UL 60335-2-89 standard, “Household and Similar Electrical Appliances--Safety--Part 2-89: Particular Requirements for Commercial Refrigerating Appliances and Ice-Makers with an Incorporated or Remote Refrigerant Unit of Motor-Compressor.” Edition 2, dated October 27, 2021.

\124\ See presentation from trade association dated April 18, 2025, in the docket for this action.

Comment: One commenter was opposed to allowing an increase in cooling capacity during a supermarket remodel, as this would lead to an increased charge size of legacy refrigerants or installation of older refrigerants. This commenter stated that allowing an increase in cooling capacity measured in BTU per hour at 25 percent could result in as many as 36 additional display cases, which would surpass a normal remodel. On the other hand, another commenter stated no objection to an allowable increase in cooling capacity during a store refresh and further commented that normal and usual remodels and redesigns should not be considered the manufacture or installation of a new system.

Other commenters supported modest increases in cooling capacity during routine remodels or layout changes. One commenter stated that it is normal and routine for supermarkets to undergo remodeling activities and modestly expand cooling capacity to accommodate additional products and layouts. The commenter asserted that an increase in BTU per hour should not constitute an installation and suggested that a workable threshold would be to allow increases up to 25 percent in BTU per hour for cooling capacity to provide a clear cut-off while accommodating routine activities. Another commenter supported the clarifications and codifying an explicit tolerance for modest cooling capacity increases during supermarket refreshes or layout adjustments, while retaining the existing triggers in the regulations. The commenter suggested that a percentage below 25 percent, notably 15 percent, is generally more aligned to the EPA's stated purpose to distinguish routine servicing from new installations in major remodels.

One commenter supported the adoption of a remodel tolerance permitting cooling capacity increases of up to 15 percent without treating it as a new installation, which is appropriate to cover typical reconfigurations and modest department expansions. They further commented that standard industry design practice for supermarket equipment must have a minimum of 10 percent excess capacity for future expansion, and allowing an increase of 15 percent could utilize this design practice. The commenter also stated that a 25 percent increase in cooling capacity would more typically reflect a major expansion that goes beyond routine activity and is more appropriately treated as a new installation.

Response: The EPA acknowledges the comments and information related to increases in cooling capacity for a supermarket system during routine remodeling. The Agency understands based on comments that such routine store refreshes, remodels, or layout changes may expand cooling capacity modestly. The EPA disagrees with commenters that suggested it would be inappropriate to allow modest expansions in cooling capacity related to routine remodels or layout changes. As noted above, even in the context of the CAA R-22 phaseout, the considered if there was sufficient cooling capacity within the system to support the expansion (e.g. new display cases), to be changes that would not trigger treatment as a new system. This is consistent with the EPA understanding that supermarket systems are typically designed for both the intended and a modest increase in capacity.

The EPA acknowledges comments that stated that standard industry practice includes designing supermarket systems to include approximately a 10 percent capacity margin above the current load. Knowing that supermarket systems are designed with a 10 percent capacity margin above the typical load could help explain why there was uncertainty among stakeholders. For example, stakeholders questioned the discrepancy between the load of a system as currently operated versus the capacity of a system as designed. The text at 40 CFR 84.54(e)(2) does not recognize that distinction. Based on the general support from industry commenters, a modest percent increase in cooling capacity is appropriate. The EPA, however, recognizes that supermarket systems are custom-built systems, designed specifically to function for a particular store. As such, there may be situations in which a modest increase in capacity is required for a store refresh, remodel, or layout change that is beyond the design capacity. Thus, the EPA is finalizing in this rulemaking to allow increases to capacity of up to 15 percent (measured in BTU per hour) to provide flexibility and accommodate a wide range of circumstances for routine activities at stores. The EPA further clarifies that an increase in capacity beyond 15 percent for supermarket systems would trigger the criteria for the installation of a new system. The EPA is addressing this issue of increasing cooling capacity only in the context of supermarket systems for which such routine refreshes typically happen and is not applying the 15 percent increase to other sectors or subsectors.

The EPA clarifies that the 15 percent increase in cooling capacity finalized in this rulemaking is intended to provide an upper bound on a supermarket system's cooling capacity before a new system installation is triggered. Specifically, the EPA is clarifying in this final rule that modifications to an existing supermarket system that increase the cooling capacity by equal to or less than 15 percent do not trigger the requirements at 40 CFR 84.54(e)(2). As an illustrative example, consider a supermarket system that is installed with a design capacity of 100,000 BTU per hour. The allowable increase in cooling capacity during a routine store refresh, remodel, or layout change would be 15,000 BTU per hour in this scenario. This cap applies throughout the life of the supermarket system, and any number of routine remodels may be performed, so long as the 15 percent cap is not exceeded relative to the cooling capacity provided at installation.

The EPA acknowledges that the associated increase of capacity with a routine store refresh, remodel, or layout change may vary depending on the specific characteristics of the supermarket system and the store itself. However, based on information provided in comments, a 15 percent increase in capacity is sufficient for such routine activities. The EPA disagrees that a 25 percent increase in capacity for a supermarket system would constitute routine activities. The EPA acknowledges and agrees that an allowable increase of 25 percent in cooling capacity would result in expansions that are beyond what constitutes as routine. The EPA recognizes the needs of retailers to perform routine store refreshes, remodels, or layout changes to meet the needs of their customers. Supermarkets and grocery stores may find that

remodels or layout changes provide other efficiency benefits even if a modest expansion of the cooling capacity is necessary. A cap of a 15 percent increase in cooling capacity allows room for such routine activities. As stated previously, the EPA is aware that supermarkets and grocery stores may perform routine remodels once or twice during the lifetime of the supermarket system. An allowable 15 percent increase could provide for more than one remodel, such that the total increase in cooling capacity from all remodels combined does not exceed 15 percent of the cooling capacity provided at installation of the supermarket system.

Comment: One commenter requested the EPA clarify the difference between increasing the capacity of a refrigeration system versus increasing the load on a system. The commenter explained that increasing the capacity is the addition of compressor power (e.g., BTU per hour) to the system and, according to the EPA's rules and public documents, adding system capacity has been a longstanding trigger for changing the intended use of a system going back to regulations for ozone-depleting substances. The commenter further explained that increasing the load on a system does not change the intended use of a system as long as there is sufficient capacity, and that in such a scenario, there would be no need to classify the system as newly installed related to the limits. Another commenter requested clarity on “system cooling capacity,” as they understand the term to mean the available cooling provided by the compressors. They commented that a store should be able to add display cases on the current system's existing cooling capacity and that the refrigerated load is not the same as the cooling capacity of the system.

Response: The EPA appreciates the comments provided for additional clarification on the allowable increase in cooling capacity for supermarket systems for routine store refreshes, remodeling, or layout changes. The EPA agrees with the understanding that the load is not the same as the cooling capacity of a supermarket system, where the load is the actual cooling drawn from the supermarket system's total capacity. The EPA agrees that expanding the load, such as through adding cases, as long as there is existing cooling capacity would not change the intended purpose of the supermarket system, which is consistent with the past practice from the phaseout of R-22 described earlier in this section. As described in the previous comment and response, the EPA is finalizing a provision to allow up to a 15 percent increase in cooling capacity for supermarket systems to allow modest increases in cooling capacity during routine store refreshes, remodels, or layout. As the EPA noted in the proposed rule, there may be the case where improvements--such as installing doors--during a routine store remodel or refresh may decrease the BTU per hour output (i.e., cooling load) required from the supermarket system.\125\ In such cases, the 15 percent allowable increase in capacity would still relate to the cooling capacity at the installation of the supermarket system.

\125\ See 90 FR 48008 (October 3, 2025).

Comment: One commenter requested that the EPA remove the component replacement threshold for installation at 40 CFR 84.54(e)(3) or provide clarity for ambiguous language that may trigger an installation if the 100 percent replacement applies collectively or individually to the compressor racks, condensers, and connected evaporator loads. The commenter stated that the more natural reading would be 100 percent replacement of all three components, but that the text could be interpreted as applying to 100 percent of one of the three components.

Response: The EPA did not propose any changes to, nor request comment on, 40 CFR 84.54(e)(3) and does not address that provision in this final rule. However, the EPA is providing additional clarity. The commenter provided two interpretations of the text. The EPA is clarifying that the more natural reading as described by the commenter is consistent with the EPA's interpretation. The intent of the language is that an installation is considered new when replacing 75 percent or more of the evaporators (by number) and 100 percent of all of the compressor racks, condensers, and connected evaporator loads of an existing system. It is not the EPA's intention for existing systems that require routine maintenance or replacements of only certain components to constitute an installation and be fully replaced.

Comment: Some commenters supported the EPA's interpretation of the term “retrofit” and requested that the Agency restate it in the final rule. Some commenters also supported the proposed rule because the costs of retrofitting existing stores to compliant refrigerants.

Response: The EPA reiterates that a “retrofit” is distinct from a store “refresh,” “remodel,” or “layout change.” The AIM Act states that for purposes of regulations issued under subsection (i), the term “retrofit” “means to upgrade existing equipment where the regulated substance is changed, which (1) includes the conversion of equipment to achieve system compatibility; and (2) may include changes in lubricants, gaskets, filters, driers, valves, o-rings, or equipment components for that purpose”.\126\ Thus, a retrofit, for purposes of the restrictions at 40 CFR part 84, subpart B, requires a change in the type of refrigerant used in a system (e.g., switching from R-404A to R- 448A). The EPA adopted that definition in the regulations at 40 CFR 84.52 and stated that the requirements of the 2023 Final Rule do not apply to retrofits.\127\ Neither the limits nor the provisions at 40 CFR 84.54(e), which specify when a system is sufficiently modified to be characterized as new and subject to the restrictions, currently apply to a retrofit. Therefore, concerns about the cost of retrofitting existing stores to compliant refrigerants are not applicable.

\126\ See 42 U.S.C. 7675(i)(7)(A).

\127\ The EPA stated that “[w]hile we recognize the Agency's authority to issue restrictions on retrofit applications in subsection (i)(7)(B)(ii), we do not view, and commenters did not suggest, that the EPA has an obligation to issue such restrictions at this time.” For further discussion, see 88 FR 73127. See also: https://www.epa.gov/climate-hfcs-reduction/frequent-questions-phasedown-hydrofluorocarbons#supermarket-systems.

Comment: Many commenters, largely food retailers, supported the delay in compliance dates as proposed for remote condensing units to provide time for manufacturers and contractors to train technicians, develop safety protocols, and update building codes. Commenters generally made the same statements to support such delays in compliance dates and changes in limits for this subsector as those made in support of the proposed changes for supermarket systems. The commenters stated that the proposed changes for remote condensing units would provide more flexibility in refrigerant choices. One commenter was supportive of the interim limit of 1,400 beginning one year earlier for remote condensing units as compared to supermarket systems, given that supermarket systems are more complex.

Response: The EPA acknowledges comments in support of the graduated schedule for remote condensing units. The EPA agrees that the graduated schedule is beneficial for this subsector. Based on comments received and after additional evaluation of remote condensing unit options currently available on the market, finalizing these

changes will address the concerns raised with the original timelines established in the 2023 Final Rule.

The EPA acknowledges commenters' request for additional time to become familiar with newer technologies that meet their needs. The graduated schedule will allow retailers to select remote condensing units with a refrigerant above the 150 or 300 limits until January 1, 2032, that may have characteristics similar to refrigerants historically used in this subsector. However, given many U.S. manufacturers transitioned their manufacturing lines to meet the previous January 1, 2026, compliance date, the EPA expects that many retailers will choose a remote condensing unit compliant with the 2032 limit prior to January 1, 2032.

Comment: Some commenters stated that there are notable differences between remote condensing unit systems and supermarket systems, and that these subsectors should not be treated the same. They also stated that the 2023 Final Rule requirements for remote condensing units should be left in place. One commenter stated that extensions may be appropriate for supermarket systems but specifically stated to retain the compliance dates and limits for remote condensing units. They commented that the EPA has traditionally considered these subsectors separately under the SNAP program and that these subsectors differ in design, purpose, and construction. They commented that the subsectors should not be treated equivalently for the purpose of considering limits. Another commenter suggested extending the stepdown compliance date and limit to January 1, 2029, for supermarket systems, but leaving in place the January 1, 2026, compliance date and limit for remote condensing units.

Commenters stated that remote condensing units have lower refrigeration capacities than supermarket systems, so these systems do not face similar safety challenges, and it is easier to comply with charge size restrictions of A2Ls. One commenter stated that many equipment manufacturers have announced launches for A2L remote condensing units recently. Another commenter stated that remote condensing units are usually installed outdoors and are less complex than supermarket systems, so they face fewer challenges regarding approval by local building code officials.

Response: The EPA agrees that the consideration of the limits and compliance dates for each sector and subsector should be assessed independently. The EPA provided separate discussions of each of its assessments in the proposed rule.

The EPA acknowledges that a variety of products and systems are used in retail food establishments including remote condensing units and supermarket systems. For each subsector addressed in this rule as well as the 2023 Final Rule, the Agency made separate assessments. Where relevant, the Agency established requirements that use a charge size cut-off for the limits (i.e., 150 or 300). The EPA did not propose and is not changing this approach in this rulemaking. The charge sizes relate to the allowable charge sizes for flammable refrigerants based on alignment with applicable safety standards. The EPA agrees that remote condensing units are, in a majority of cases, under this size threshold; and thus, these types of equipment using flammable refrigerants, including those classified as A2L, do not face as many challenges with building codes. However, the EPA notes that some remote condensing units may still face safety challenges related to building codes. Therefore, based on the totality of the record, the EPA concluded the graduated schedule would be appropriate.

Comment: Many commenters suggested alternate compliance dates or limits compared to the proposal. Commenters provided similar suggestions for compliance dates as with the supermarket systems subsector, including establishing an interim limit until July 1, 2026, January 1, 2028, or January 1, 2029, at which point the limits would return to 150 or 300, as applicable. Commenters in support of the January 1, 2029, compliance date stated that this would be appropriate as it aligns with the next HFC phasedown step while still allowing flexibility in the near term. One commenter stated that if an extension were provided for remote condensing units, it should be no more than one year.

Response: The EPA disagrees with the compliance dates provided by commenters ranging between July 1, 2026, and January 1, 2029, for the limits of 150 or 300, as applicable. While there are available remote condensing units that are compliant with the 150 or 300 limits, the EPA received many comments describing retailers and code officials needing additional time to adopt these technologies, particularly for those using A2L refrigerants. Building codes is among the factors that the EPA factors in, to the extent possible, consistent with subsection (i)(4) of the AIM Act; however, it is not the sole factor.

The EPA also understands that there are many available remote condensing unit equipment options currently offered by manufacturers, which use regulated substances that would be compliant with a limit of 150 or 300, as appliable. The availability of substitutes is among the criteria that the EPA factors in to the extent possible, consistent with subsection (i)(4); however, it is not the sole factor. The EPA understands that amending the compliance date to January 1, 2032, means it is after the 70 percent reduction step of the HFC phasedown schedule in 2029, which in and of itself will constrain HFC production and import and could result in an overall price increase for HFCs. However, as stated in response to similar comments on the amended compliance date for supermarket systems, the HFC phasedown schedule established by subsection (e) of the AIM Act and the technology transitions requirements at subsection (i)(4) are wholly separate.

While subsection (i)(4) requires the EPA to factor in the remaining phasedown period to the extent practicable, that is one factor, like availability of substitutes, that the EPA considers. Both availability of substitutes and the remaining phasedown schedule for HFCs could result in many retailers deciding to choose a remote condensing unit that is compliant with the limits of 150 or 300, as applicable, prior to January 1, 2032. Using a graduated schedule with limits of 150 or 300, as applicable, beginning on January 1, 2032, is based on factoring in, to the extent practicable, all of the subsection (i)(4) factors, including, but not limited to, commercial demands, affordability for residential and small business consumers, safety, consumer costs, and the factors previously mentioned in this response.

Comment: One commenter suggested adjusting the interim limit to 750 rather than 1,400, and lowering the limit to 150 or 300, as applicable, in 2032. The commenter stated this aligns more closely with currently available technology. Another commenter requested the interim limit for remote condensing units be set at 1,430, rather than 1,400, to allow for continued use of R-134a, as they stated that there are no production-ready compressors for wine cooling remote condensing units with refrigerants meeting the 150 limit. They stated that by setting the limit to allow for the use of R-134a, manufacturers would not need to redesign products for the interim period between 2026 and 2032.

Response: The EPA disagrees that an interim limit of 750 would be appropriate for the remote condensing units subsector. The EPA acknowledges that to a large extent, in the 2023 Final Rule, the Agency set limits of 150, 300, or 700 for sectors or subsectors.

However, the EPA did not set a limit of 750 in any sector or subsector. Moreover, the Agency made its decisions based on information specific to each relevant sector or subsector. As described elsewhere in this section, two HFC refrigerant blends (i.e., R-448A and R-449A) are currently being used in new remote condensing unit installations and are below the 1,400 limit. Based on information from retailers and in comments on the proposed rulemaking, allowing use of these refrigerant blends would provide sufficient flexibility in the interim timeframe. An interim limit of 750 would not allow these substitutes and would significantly limit the flexibility in refrigerant choice for remote condensing units during the interim period.

The EPA also disagrees with setting the interim limit at 1,430 for remote condensing units. While this limit would allow for the use of R- 134a in the interim period, the interim limit of 1,400 provides additional available A1 refrigerant options for wine cellar cooling remote condensing units, including R-448A and R-449A.

Comment: Many commenters stated that the proposed delay in compliance dates for remote condensing units conflicts with the AIM Act's requirement for phasing down consumption of HFCs, and there will be a much greater demand for HFCs by 2032 than allowed consumption can support. Commenters stated that delays would elevate HFC demand, cause allowance shortages, and shift allowances away from newer technologies to legacy refrigerants. Commenters also pointed to the impacts of heightened demand and decreased supply on the costs of refrigerants. They stated that the impacts caused by higher demand would cause higher prices for all HFC refrigerants and affect other sectors outside of commercial refrigeration, and that these costs would get passed on to American consumers.

Response: The EPA acknowledges these comments. The EPA understands that amending the compliance date to January 1, 2032, means it is after the 70 percent reduction step of the HFC phasedown in 2029, which will constrain HFC production and import and could result in an overall price increase for HFCs. However, as stated in response to similar comments on the amended compliance date for supermarket systems, the HFC phasedown schedule established by subsection (e) of the AIM Act and the factors in subsection (i)(4) are wholly separate. While subsection (i)(4) requires the EPA to factor in, to the extent practicable, the remaining phasedown period, that is one factor, like availability of substitutes, that the Agency considers. In addition, the phasedown itself is expected to be a market driver for the transition of remote condensing units that use refrigerants that are below the 2032 limits. As noted, overall prices could increase for HFCs as the statutory HFC phasedown continues. Since the phasedown is based on the exchange values listed in AIM Act subsection (c), it disincentivizes the use of regulated substances that are close to, or above, the interim limit, while incentivizing those that are below the 150 or 300 limit, as applicable, including new options provided by U.S. chemical companies.

Comment: Many commenters stated that there are substitutes and technologies available for remote condensing units. One commenter stated that many distributors are currently selling remote condensing unit systems using refrigerants below the limit of 150 or 300, as applicable, and that such systems using A2L refrigerants like R-454A and R-454C are already being sold to customers. Other commenters similarly stated that there are multiple SNAP listings of available substitutes for remote condensing units with safety standards incorporating UL 60335-2-89 and ASHRAE 15-2022. Commenters stated that the EPA already demonstrated that there are substitutes available for the remote condensing units subsector, and that the Agency has already met the statutory test for demonstrating that there are available substitutes. One commenter further stated that they use multiple available substitutes for commercial refrigeration categories addressed in this rulemaking in their standard product offerings, including R- 454A, R-454C, R-455A, and CO2. They commented that they provide a product line that is currently manufactured and sold that meets the 150 or 300 limits, as applicable, including remote condensing units and unit coolers, remote condensers, and refrigerant rack systems. Another commenter stated that refrigerant suppliers have been supplying the remote condensing unit market with A2Ls and that several national convenience stores have confirmed that they are in the process of converting to such systems with A2L refrigerants. One commenter stated that they have moved forward with A2L refrigerants (specifically, R-454A) with their vendors and will continue that path forward. They commented that all of their vendors are aligned and have moved forward with equipment using R-454A.

Response: The EPA appreciates the information provided by commenters on the available remote condensing units that use refrigerants that are compliant with the limits of 150 or 300. The EPA agrees that there are substitutes available for remote condensing units that comply with the 2023 Final Rule compliance timelines and indicated in the 2023 Final Rule that several substitutes, including CO2 and some A1 and A2L HFC blends, were available or would soon be available in time for the remote condensing units subsector compliance date of 2026.\128\ This was based partly on the understanding that SNAP Rule 26 would list several of these identified substitutes as acceptable for the subsectors, subject to use conditions, soon after finalization of the 2023 Final Rule. The EPA finalized SNAP Rule 26 and listed seven A2L substitutes as acceptable, subject to use conditions, for use in new remote condensing units.\129\ Two are non-HFC refrigerants (HFO-1234yf and HFO-1234ze(E)) and thus are not subject to subsection (i) rules. Five are HFC/HFO blends (R- 457A, R-516A, R-454C, R-455A, and R-454A), which, except for R-454A, satisfy the 150 limit for installation in new remote condensing units that have a charge size of 200 pounds or more. All of these refrigerants may also be installed in such systems that have a charge size less than 200 pounds, or as part of the high temperature side of a cascade system. While increasing the number of refrigerants listed as acceptable under the SNAP program can provide more options in the long term, more time is needed for chemical suppliers to produce them in sufficient quantities. The EPA is seeking to avoid supply chain issues similar to those that arose with the deployment of the new refrigerant blend, R-454B, in the residential and light commercial AC/HP subsector. In that situation, while the refrigerant was being manufactured in sufficient quantities, it was not available

in the field for equipment installation and servicing.\130\

\128\ See 88 FR 73098 (October 24, 2023).

\129\ See 89 FR 50410 (June 13, 2024).

\130\ See Memorandum--Overview of R-454B Refrigerant Shortage and Current Status, in the docket for this action.

Moreover, as noted elsewhere in this section, the EPA is factoring in the availability of substitutes, to the extent practicable, and reaffirms it is not the sole factor the Agency considers. The EPA finds that a graduated schedule is more appropriate for remote condensing units for reasons other than availability of alternatives. The record reflects that additional alternatives and system configurations, including those using A1 or A2L refrigerants, are becoming more widely deployable as equipment listings and product safety standards are implemented, supply chains mature, and field experience expands. This approach also recognizes that other factors, such as building codes, are not a universal constraint in this subsector; however, there may be situations where they remain a near-term barrier.

Comment: Some commenters provided similar information and comments for remote condensing units as they did on supermarket systems on the challenges of availability and using substitutes. One commenter stated that many refrigerants that meet the 150 or 300 limit, as applicable, are either unavailable or withdrawn from the market, and that equipment manufacturers have not yet scaled to demand. One commenter noted that they have experienced issues deploying A2L refrigeration systems. They stated that manufacturers currently only offer a handful of A2L systems and most are small remote condensing units that are not suitable for large grocery stores. One commenter stated that even where A2L equipment is installed, many installation companies are having issues with sourcing A2L refrigerants in a reliable or timely manner.

Response: The EPA acknowledges the comments that there may be some challenges with the adoption of A2L technologies in some cases, including related to availability of equipment on the market. The EPA agrees that additional time is necessary for remote condensing units to transition. The EPA agrees that existing challenges for adoption of A2L refrigerants warrant amending the schedule and providing an interim limit. Retailers may need additional time to become familiar with these technologies. Further, technicians may need additional training to safely handle equipment using flammable refrigerants. The amended provisions will also provide sufficient time for newer refrigerants and the equipment using them to become more widely available and have proper supply chains established.

Comment: One commenter stated that A2L systems have already been developed for the 2026 compliance date, and they are expected to be comparable in cost to HFC systems. Another commenter compared price quotes from a distributor for a walk-in cooler, one with R-449A and one with R-454A. The commenter stated the price difference was largely based on the indoor evaporator component with installed refrigerant detection and solenoid shut-offs; however, the refrigerant saved by detecting and stopping leaks early offset the cost difference between systems over the lifetime of the system. Another commenter stated that certain refrigerants below the limit of 150 or 300 provide cost savings, including reduced operating costs through greater energy efficiency.

Response: The EPA acknowledges comments provided on the costs of remote condensing units that use A2L refrigerants, particularly how they compare to systems using legacy refrigerants. Comments suggest refrigerant costs will be similar, there will be higher capital costs and lower operating costs, and note equipment design features that are outside the scope of this rulemaking. The EPA also understands that consistent with certain updated safety standards that equipment is certified as meeting, A2L remote condensing units may have design requirements, such as refrigerant leak detection devices, which may add to the capital costs.

The EPA acknowledges that in some instances, equipment using refrigerants below the 150 or 300 limit can provide energy efficiency benefits and reduced operating costs. The Agency notes that there are many factors that retailers may consider based on the individual needs for a particular application at their store. As noted by commenters in section IV.C of this preamble, retailers on average have slim profit margins, which may cause challenges in absorbing the higher capital costs of equipment using newer refrigerants. Further, commenters have noted that there may be challenges related to installing equipment with refrigerants with flammability characteristics. Thus, the EPA is establishing the graduated schedule for the retail food remote condensing units subsector with consideration of these and other factors.

As described in other comments in this section, many retailers have made announcements and commitments to transition and build new stores using available substitutes such as CO2 or A2L refrigerants. Thus, the EPA expects a portion of the market will transition prior to 2032 to available substitutes that meet the limit of 150 or 300, as applicable. Further, as described elsewhere in this section, the EPA expects market forces and the HFC phasedown to cause other retailers also to transition ahead of 2032.

Comment: Commenters stated that building code updates have occurred rapidly across the country to allow the use of A2L refrigerants. They note that 49 states have recognized A2L use either through code updates, legislation, or interpretive letter and that the remaining codes are being updated on timelines to allow compliance with the compliance dates finalized in the 2023 Final Rule. One commenter stated that home rule structures do not alter the assessment of building code readiness, as statewide adoption of the 2024 model codes or equivalent statutory authorization does not default to a prohibition on A2L use. Other commenters stated that the revised compliance schedule would allow local jurisdictions the time necessary to adopt local building and fire safety codes to allow the deployment of A2L refrigerants. Some commenters argued that local building code processes and approvals would present hurdles to the adoption of equipment using A2L refrigerants. They state that local jurisdictions may prohibit the use of A2L refrigerants due to safety concerns.

Some commenters provided more specific information in their comments on building codes as they relate to remote condensing units. One commenter stated that due to the relatively lower refrigeration capacities of remote condensing units compared to supermarkets systems, it is relatively easier to comply with the charge size restrictions for A2L refrigerants. They note that, considering the lower charge size, many manufacturers have launched remote condensing unit equipment using A2L refrigerants. Another commenter similarly stated that remote condensing units do not face the same building code challenges for adopting A2Ls as supermarket systems. They note that remote condensing units are less complex and are often installed outdoors, which would present fewer challenges regarding approval by local building code officials.

Response: The EPA appreciates the comments and information provided on the status of updated building codes across the country and acknowledges that rapid adoption has taken place. The EPA also recognizes that building codes updates have not been completed uniformly throughout all states and

local jurisdictions throughout the country. As noted in response to other comments, the majority of remote condensing units are under typical charge size thresholds that would otherwise present challenges related to using refrigerants with lower flammability characteristics (i.e., A2Ls) in the equipment. The EPA recognized this when establishing limits in the 2023 Final Rule where a distinction was made at a charge size of 200 pounds for the limits of 150 or 300 for remote condensing units. This cut-off was established with consideration of building codes to allow a wider range of refrigerant choices for smaller remote condensing units to manage safety and other factors. In other cases, as commenters noted, remote condensing units may be installed outside, further limiting challenges for installation based on building codes.

As the EPA acknowledged, not all jurisdictions have fully completed adoption of updated building codes. The EPA is amending the compliance date for the limits of 150 or 300, as applicable, for remote condensing units, to allow retailers and building code officials more time to become more familiar with remote condensing units that use refrigerants with flammability characteristics (e.g., A2Ls). Even though building codes may pose less of a barrier to adopting remote condensing units that use A2Ls than for other equipment, including supermarkets systems, the Agency still finds it appropriate to provide an interim limit and extend the deadline for the lower limit of 150 or 300, as applicable.

Comment: Some commenters stated that the EPA should provide specific relief where a discrete sub-category demonstrates a near-term constraint. Commenters provided examples of certain wine cellar coolers or milk coolers and niche laboratory cooling applications and noted that the relief should be minimal in volume, time-limited, and sunset no later than January 1, 2029. One commenter stated that a sector-wide raised limit is not the least disruptive option and would be arbitrary where narrower tools suffice (i.e., targeted relief). They commented further that potential barriers in certain sub-categories could include recertification testing timing at labs for specific capacity classes and cabinet or coil configurations and component availability issues in low-temperature applications for retail food remote condensing units. Some commenters also suggested that an alternative could be to authorize the use of certified reclaimed refrigerant for first fill in lieu of compliance with limits. One commenter stated that any needed relief after 2029 should only be available through a formal variance mechanism with public notice, annual review, hardship criteria, and cumulative impact evaluation against the allowance balance. The commenter also stated that such a targeted relied process would be a logical outgrowth of the proposed rule.

Response: The EPA appreciates comments seeking targeted relief for certain remote condensing units. While the EPA is concerned about impacts to certain wine cellar coolers or milk coolers and niche laboratory cooling applications, the Agency did not propose and thus is not establishing provisions for remote condensing units that would be applicable to a subset of equipment in this rulemaking. These considerations are outside the scope of this rule and would require additional analysis by the Agency as well as additional notice. Nonetheless, the EPA is finalizing an interim limit of 1,400 and extending the compliance date for the lower limit of 150 or 300, as applicable, until January 1, 2032, thus providing relief for all remote condensing units, including these applications.

Comment: Multiple commenters supported the proposed limit of 700 for cold storage warehouses noting they are comparable to other subsectors like data centers and IPR. They asserted that categories of subsectors are defined by certain limits, and that the cold storage warehouse subsector was placed in the incorrect category with the limits of 150 or 300 as applied in the 2023 Final Rule.

Response: The EPA acknowledges the support for raising the limit to 700 for regulated substances used in cold storage warehouses. The concerns provided in comments are similar to those that were brought to the EPA's attention in advance of the proposal. The EPA established the requirements in the 2023 Final Rule based on the information available at the time for this subsector. The Agency received additional information after finalization of that rule and during the comment period for this rule. The graduated schedule established in this rule is based on consideration of information now available to the Agency. The EPA anticipates that the graduated schedule for cold storage warehouses will provide sufficient time for many of the concerns identified by commenters to be addressed, including broader building code adoption that may enable additional lower flammability refrigerant options and more uniform deployment of complex systems.

The EPA disagrees with the assertion that categories of subsectors are defined by certain limits, and that the cold storage warehouse subsector was placed in the incorrect category. In the 2023 Final Rule, the EPA established certain limits for each subsector based on the evaluation of the AIM Act (i)(4) factors independently for each subsector at the time of that rulemaking. The EPA has considered these factors and the new information provided in establishing the appropriate graduated schedule for the cold storage warehouses subsector. For additional discussion, refer to the Response to Comments document found in the docket for this rule.

Comment: Many commenters stated that the EPA has already listed multiple substitutes below the 150 or 300 limit, as applicable, with safety standards incorporating UL 60335-2-89 and ASHRAE 15-2022. However, one commenter stated there is no indication that acceptable A1 refrigerants below the 150 limit are available or have received SNAP approval. They also note that SNAP approval of a substitute does not equate to commercially available, citing R-410B as an example. Some commenters noted that the U.S. cold storage industry has long used low- charge ammonia systems and is rapidly expanding its use of CO2, with 380 industrial sites having installed CO2. Other commenters cited the 2023 GCCA Productivity and Benchmarking Survey report that showed 91 percent of responding cold storage warehouses currently use ammonia as their refrigerant, 10 percent use synthetic F-gas refrigerant, and five percent use carbon dioxide as their refrigerant.\131\

\131\ This comment highlighted that the numbers do not add up to 100% due to the fact that some cold storage facilities use multiple refrigerants.

Response: The EPA agrees that substitutes previously identified as available to meet the upcoming January 1, 2026, restriction for this subsector may need additional time to become commercially available. In particular, the revisions to the compliance dates in this rulemaking address concerns about safety considerations in densely populated areas and availability of sufficient compliant refrigerant options across the subsector in the near term. The EPA reiterates that nothing in this final rule will prevent use of refrigerants below the limits of 150 or 300 prior to 2032. The Agency anticipates that many cold storage warehouses will continue to use ammonia and other substitutes where appropriate.

As stated previously, SNAP Rule 26 listed seven non-toxic, lower flammability (i.e., A2L) substitutes as

acceptable, subject to use conditions, for use in new cold storage warehouses.\132\ These are HFO-1234yf, HFO-1234ze(E), R-457A, R-516A, R-454C, R-455A, and R-454A. All except one (e.g., R-454A) are below the limit of 150 for the installation in new cold storage warehouses that have a charge size of 200 pounds or more. All of these refrigerants could also be installed in new systems that have a charge size less than 200 pounds, or as part of the high temperature side of a cascade system. While increasing the number of refrigerants listed as acceptable under the SNAP program can provide more options in the long term, more time is needed for chemical suppliers to produce them in sufficient quantities. The EPA is seeking to avoid supply chain issues similar to those that arose with the deployment of the new refrigerant blend, R-454B, in the residential and light commercial AC/HP subsector. In that situation, while the refrigerant was being manufactured in sufficient quantities, it was not available in the field for equipment installation and servicing.\133\ Some of these substitutes are currently commercially available, including HFO-1234yf, HFO-1234ze(E), R-454C, and R-454A; however, others will take time to become commercially available.

\132\ See 89 FR 50410 (June 13, 2024).

\133\ See Memorandum--Overview of R-454B Refrigerant Shortage and Current Status, in the docket for this action.

Comment: One commenter stated that the refrigerant highlighted in the March 6, 2025, request from the Coalition for the Use of Safe and Efficient Refrigerants (CUSER) to the EPA, R-513A, is not suitable for low-temperature applications needed for frozen foods due to its normal boiling point of -20.5 [deg]F. They stated the same is true for R-450A. They also stated that a refrigerant such as R-448A is much more compatible for low-temperature cold storage applications with its normal boiling point of approximately -45 [deg]F.

Response: The EPA appreciates the technical information this commenter shared. The EPA notes that one reason for raising the limit for cold storage warehouses is to provide additional options, like R- 513A, to be used in densely populated areas in the interim period while other options, including several A2L substitutes that were listed in SNAP Rule 26, can be commercially developed. This will allow warehouse developers and operators to use other refrigerants that would comply with the limit of 150 or 300, as applicable, beginning in 2032. The EPA notes that R-448A would not be allowable as a refrigerant for cold storage warehouses under the graduated schedule in this rulemaking, as it is above the limit of 700. As described in this section, there are other options for cold storage warehouses that meet the needs of low- temperature cold storage applications.

Comment: Many commenters opposed the proposal for adjusting the limits and schedule for cold storage warehouses. One commenter noted that the EPA has never previously proposed or referred to a limit of 700 for these systems, and it is inappropriate since the EPA already justified the lower limits in the 2023 Final Rule. Multiple commenters stated that sector-wide deferrals for cold storage warehouses are not warranted--particularly after January 1, 2029, when the AIM Act reduces supply of HFCs to 30 percent of the baseline period. Multiple commenters stated that delaying the implementation until 2032 will negate emission reductions and go against the AIM Act's requirement for a rapid transition to safer alternatives. Multiple commenters stated that there are enough alternatives in use to justify the original deadlines established in 2023. One commenter stated that allowing a limit of 700 would not reduce costs, and it could disrupt the market. One commenter stated that the EPA must maintain pre-existing timelines and limits for commercial refrigeration equipment for reasons that include avoiding duplicative costs for manufacturers and stranded assets, minimizing costs to consumers, preserving American jobs and leadership, and preventing refrigerant shortages and price spikes.

Response: The EPA disagrees with commenters that there are enough alternatives to justify the original deadlines established in 2023 for the reasons discussed within this section. The EPA also acknowledges these commenters' opposition to altering the limits and compliance date for cold storage warehouses and preference for retaining the requirements in the 2023 Final Rule; however, the EPA is finalizing a graduated schedule based on the totality of the record for this subsector.

The EPA understands that any delay in the compliance dates as compared to the 2023 Final Rule for cold storage warehouses could allow the continued use of and demand for certain refrigerants. However, as stated above, cold storage warehouses have historically and widely used ammonia, a refrigerant that is not impacted by the HFC phasedown. There is nothing in this final rule that precludes the continued use of ammonia, or other refrigerants below the 150 or 300 limits, as applicable. In addition, based on information provided prior to the proposal and in comments, the EPA understands that over 90 percent of cold storage warehouse refrigeration systems in the United States used either ammonia or CO2.\134\ The EPA anticipates that this trend will generally continue for new installations of cold storage warehouses, while the graduated schedule in this rulemaking allows flexibility for continued use of HFC refrigerants below the 700 limit in the interim period.

\134\ See letter provided by IIAR, dated June 9, 2025, in the docket for this action.

With regards to commenters' assertions of duplicative costs for manufacturers and stranded assets, the Agency reiterates that nothing in this rule prevents manufacturers from continuing to manufacture and sell equipment before the effective date of the 150 or 300 limits, as applicable. The EPA does not anticipate a significant shift away from the current use of refrigerants that are below those limits. The EPA agrees that prices and demand for HFC refrigerants will likely increase in the interim period. The Agency discusses this in more detail in another response in this section. In general, the EPA expects that these price increases will be market drivers to shift industry towards refrigerants below the 150 or 300 limits for cold storage warehouses. Commenters noted the potential for the final rule to impact costs to consumers as well as jobs; however, for this subsector, the Agency did not receive information to sufficiently support these claims.

Comment: Multiple commenters requested keeping the limit at 700 permanently instead of lowering it in 2032 to 150 or 300. They asserted that it is inappropriate to assume that additional compliant substitutes would be available after seven years. Another commenter recommended that the limit could be removed entirely for cold storage warehouses.

Response: The EPA disagrees with commenters' assertions that it is inappropriate to adopt a 150 or 300 limit permanently. The EPA also disagrees that the limits for cold storage warehouses should be removed entirely. The 2023 Final Rule responded to petitions to restrict fully, partially, or with a graduated schedule the use of HFCs in cold storage warehouses. This rule reconsiders the limits and timing based on the totality of the record which includes identified viable substitutes. The SNAP program listed several additional lower toxicity alternative

refrigerants for cold storage warehouses that would meet the 150 or 300 limit requirements, as applicable, in June 2024. The graduated schedule provides additional time to adopt these more recently listed compliant refrigerants. The EPA intends to continue to monitor the transition. If at a later date, the EPA becomes aware of information that suggests six additional years was insufficient, at that time, the Agency can decide to revisit the 2032 compliance date. It is unlikely such an assessment could be made for several years.

Comment: Multiple commenters requested aligning the limits for retail food subsectors with cold storage warehouses, and to apply a limit of 1,400 to allow for the use of R-448A and R-449A. Some indicated that this would allow an organic transition to A2L refrigerants as they become more widely available. One commenter mentioned there are still many warehouses that require a non-toxic refrigerant. Another commenter agreed with aligning the limit of retail food subsectors with cold storage warehouses, however disagreed with the proposed increased limit and delayed date.

Response: The EPA appreciates the comments to adjust the limits to align across retail food subsectors and cold storage warehouses, or remove them entirely. However, the Agency's limits are based on assessment of the specific subsector. In the 2023 Final Rule, the Agency often used the same numerical limits (e.g., 150 and 700) since often the same refrigerants where being considered for multiple applications. Based on the information provided ahead of the proposed rule and during the comment period, the Agency concludes that a 700 limit as part of a graduated schedule is appropriate for cold storage warehouses. Refrigerants, including but not limited to R-513A, were identified as interim solutions and these refrigerants are below the 700 limit. The EPA recognizes that in some cases, a non-toxic refrigerant is required for a cold storage warehouse application. In this case, the EPA again notes that there are available substitutes, such as R-513A, that are below the interim limit of 700 and have lower toxicity characteristics (i.e., ASHRAE safety classification “A”).

Comment: Multiple commenters noted that the proposed delays to 2032 and interim limits would elevate near-term HFC demand while supply tightens, misaligning the AIM Act's intended ability to guide an orderly transition and the phasedown schedule. One commenter stated that if compliance dates are delayed and limits are relaxed, they anticipate refrigerant shortages from 2027 onward. Based on the EPA's own modeling, this will create a future shortage of the supply of refrigerants with higher limits, including refrigerants originally intended for use in servicing legacy equipment. Multiple other commenters recommended adjusting the compliance date to January 1, 2029, to synchronize with the allocation phasedown schedule.

Response: As a general matter, the EPA does not agree that limits set under the Technology Transitions subsection of the AIM Act need to align with the dates Congress established for the phasedown schedule under subsection (e). These are two distinct subsections, each with their own clear direction. While the additional time until 2029 would provide limited flexibility for cold storage warehouses, the EPA concludes that it is not enough time to address concerns for this subsector. Congress' direction under subsection (i) are to the extent practicable, factor in “the remaining phase-down period for regulated substances,” among other factors. In addition, the phasedown itself is a separate and key market driver for all refrigerant users. The EPA has considered the remaining phasedown period as well as the other factors listed in subsection (i)(4) of the AIM Act and factored them in to the extent practicable, consistent with Congressional direction.

The EPA acknowledges concerns with increased costs of HFC refrigerants if there is an increase in demand resulting from delayed compliance dates. The prices of HFCs will likely increase as the phasedown continues notably around the seventy percent stepdown in 2029, irrespective of whether the EPA amends the compliance date or limit for the cold storage warehouse subsector. The EPA expects that if there are price increases, companies may choose to transition to refrigerants that are below the limits of 150 or 300, as applicable, prior to January 1, 2032. Thus, the phasedown itself is expected to be a market driver for the transition of cold storage warehouses to substitutes that are below the 2032 limits, consistent with the statutory HFC phasedown under the AIM Act.

Comment: Multiple commenters stated that the record does not support claims that substitutes are unavailable or that building codes require sector-wide deferrals. Another commenter noted that since 2021, nearly every U.S. jurisdiction has acted to authorize the use of A2L refrigerants through adoption of the 2024 model codes or interim measures consistent with those provisions. They also noted that 49 states have formally recognized A2L use either through adoption of updated model codes, enactment of state legislation, or issuance of letters of approval by the state fire marshal or building authority. 29 states have passed legislation explicitly allowing alternative refrigerants, and several others, including Idaho, Kentucky, Michigan, Nevada, and the District of Columbia, have issued interpretive letters confirming that A2L products listed and labeled to UL standards and installed in accordance with ASHRAE 15 are permissible under existing codes. Another commenter noted that the International Code Council (ICC) has confirmed commercial and residential use of A2L refrigerants is allowed following code changes in the 2024 IBC, 2024 International Residential Code (IRC), IFC, and IMC. One commenter states that cold storage warehouses do not face the same challenges with local building codes as described above for supermarkets because they are not consumer-facing facilities.

Response: The EPA acknowledges commenters who stated that the record does not support claims that substitutes are unavailable or that building codes require sector-wide deferrals. The Agency also acknowledges information provided by commenters indicating that nearly all U.S. jurisdictions have taken action to authorize the use of A2L refrigerants through adoption of the 2024 model codes or equivalent interim measures, that most states have formally recognized A2L use through code adoption, legislation, or letters of approval, and that the ICC has confirmed A2L use in commercial and residential applications following changes in the 2024 IBC, IRC, IFC, and IMC. In light of these developments, the EPA agrees that building code adoption is not a sector-wide barrier for cold storage warehouses.

At the same time, the EPA finds that a graduated schedule is more appropriate for cold storage warehouses for reasons other than availability of alternatives. The record reflects that additional alternatives and system configurations, including those using A1 or A2L refrigerants, are becoming more widely deployable as equipment listings and product safety standards are implemented, supply chains mature, and field experience expands. This approach also recognizes that codes are not a universal constraint in this subsector; however, there may be situations where codes remain a near term barrier. It also addresses the complexity of deploying systems designed for new refrigerants and the

need to align with capital planning and workforce training.

Given that the vast percentage of this subsector does not currently use and are not expected to suddenly begin using HFCs, the EPA expects that the impact of this change to a gradated schedule will likely have a minimal impact on the products manufacturers offer. The EPA expects a strong portion of the market to choose a refrigerant below the limits of 150 or 300, as applicable, for new cold storage warehouse installations prior to 2032. Similarly, the EPA notes the limited use of HFCs will likely result in a limited change in demand.