USA: EPA Section 608, the AIM Act and the safety standards ASHRAE 15 and 34
Refrigerant rules in the USA: Section 608 certification, leak repair from 50 and 15 lb, the AIM Act and Technology Transitions with the 2026 changes, ASHRAE 15/34 and UL 60335-2-40.
Key points
- Technicians who open the refrigerant circuit must hold EPA certification under Section 608: Type I, II, III or Universal [1][3].
- Knowingly venting refrigerants during service is prohibited. The refrigerant must be recovered with certified equipment [1][3].
- Leaks must be repaired when the leak rate exceeds 10, 20 or 30 % per year: from 50 lb for ozone-depleting refrigerants and, since 1 January 2026, from 15 lb for HFCs and substitutes with a GWP above 53 [1][2].
- The AIM Act phases down HFCs and limits the GWP of new equipment. On 26 May 2026 EPA postponed several deadlines, including those for supermarkets and cold storage warehouses, to 2032 [2][4][5].
- Installation safety is governed by ASHRAE 15 and 34 through the building codes, and by UL 60335-2-40 for air conditioning and heat pumps with A2L [6].
Two laws: the Clean Air Act and the AIM Act
In the USA refrigerants are mainly governed by two federal laws. The Clean Air Act, Section 608, with the rules in 40 CFR Part 82, Subpart F, covers refrigerant handling: technician certification, the venting prohibition, recovery and leak repair [1][3]. The American Innovation and Manufacturing Act of 2020 (AIM Act), with the rules in 40 CFR Part 84, covers the HFC phase-down, which refrigerants new equipment may use and, since 2024, leaks and reclamation for HFC systems [2]. States can have stricter rules, California for example.
Section 608 certification
Anyone who maintains, services, repairs or disposes of equipment in a way that could release refrigerant must be certified. Certification is obtained by passing a test with an EPA-approved certifying organisation, and it does not expire [1][3]. Persons who dispose of small appliances or motor vehicle air conditioners do not need to be certified, and apprentices are exempt while a certified technician closely and continually supervises them (40 CFR 82.161(a)) [1]. There are four levels:
- Type I: small appliances, factory-charged and hermetically sealed with 5 lb of refrigerant or less, for example refrigerators and small air conditioners.
- Type II: medium-, high- and very high-pressure appliances, for example split air conditioning and commercial refrigeration.
- Type III: low-pressure appliances, for example some chillers.
- Universal: all three types.
Refrigerant may only be sold to certified technicians, with some exemptions for small cans for motor vehicle air conditioning [3].
Venting prohibition and recovery requirements
It is prohibited to knowingly vent ozone-depleting refrigerants and their substitutes, for example HFCs, during service, maintenance, repair and disposal. There are exemptions for small releases during correct work, and for some substances that EPA has exempted [1][3]. Before an appliance is opened or disposed of, the refrigerant must be recovered with certified recovery equipment down to the vacuum level set in the rules.
Leak repair
Appliances with 50 lb or more of an ozone-depleting refrigerant, for example R22, must be repaired when the leak rate exceeds a certain share of the charge per year [1]. Since 1 January 2026 corresponding requirements also apply to appliances with 15 lb or more of HFCs or of substitutes with a GWP above 53. The rules are in 40 CFR 84 Subpart C, the so-called ER&R rule [2]. Residential and light commercial air conditioning and heat pumps are exempt from these HFC leak repair rules (40 CFR 84.106(a)(3)(ii)).
| Type of appliance | Leak rate threshold per year |
|---|---|
| Comfort cooling, refrigerated transport and other appliances | 10 % |
| Commercial refrigeration | 20 % |
| Industrial process refrigeration | 30 % |
When the threshold is exceeded, the leak must normally be repaired within 30 days (120 days if an industrial process shutdown is required) and the repair verified (40 CFR 82.157(d) and 84.106(d)) [1][2]. Otherwise the owner must prepare a plan to retrofit or retire the appliance. Large commercial and industrial refrigeration systems with 1,500 lb or more are also subject to requirements for automatic leak detection [2]. From 2029, servicing in certain sectors must be done with reclaimed refrigerant [2].
AIM Act: phase-down and Technology Transitions
The AIM Act phases down the production and import of HFCs in the USA to 15 % of the baseline in 2036, with allowances allocated to producers and importers [2]. The Technology Transitions programme, in 40 CFR 84 Subpart B, sets a maximum GWP for new equipment by sector and date. For example, since 2025 self-contained residential and light commercial air conditioners and heat pumps with a refrigerant GWP of 700 or more may not be manufactured or imported, and split systems with such refrigerants may not be installed (VRF systems since 2026); in practice A2L refrigerants such as R32 and R454B are used [5].
On 26 May 2026 EPA published a final rule that changes several deadlines [4][5]:
- Supermarket systems and remote condensing units: new remote condensing units in retail food refrigeration must use a refrigerant with a GWP below 1,400 from 27 July 2026, and new supermarket systems from 1 January 2027 (40 CFR 84.54(c)(11)–(12)). From 1 January 2032 the limit is a GWP below 150 for systems with 200 lb or more, and below 300 for smaller systems and the high-temperature side of a cascade.
- Cold storage warehouses: new systems must use a refrigerant with a GWP below 700 from 27 July 2026 (40 CFR 84.54(c)(9)), and the limits of 150 and 300 apply from 1 January 2032. Industrial process refrigeration other than chillers ((c)(10)): from 1 January 2026, at evaporating temperatures above −30 °C, a GWP below 150 (200 lb or more) or below 300 (smaller systems and the high-temperature side of a cascade); from 1 January 2028, at −50 to −30 °C, a GWP below 700.
- Residential and light commercial air conditioners and heat pumps with a GWP of 700 or more that were manufactured or imported before 1 January 2025 may be installed without the former deadline of 1 January 2026.
Safety standards
ASHRAE 34 sets the designations and safety classes of refrigerants, for example A1, A2L and A3. ASHRAE 15 is the safety standard for refrigeration systems and sets, among other things, the maximum refrigerant quantity in occupied spaces and the requirements for machinery rooms [6]. The standards become requirements through the model codes adopted by states and municipalities, for example the International Mechanical Code and the Uniform Mechanical Code. Requirements can therefore differ between states. For air conditioners and heat pumps with A2L refrigerants, the product standard UL 60335-2-40 applies, with requirements for leak detection and ventilation for larger charges.
Ammonia (R717) systems with 10,000 lb or more of anhydrous ammonia in a process fall under OSHA's process safety management standard, 29 CFR 1910.119 (Appendix A); retail facilities are exempt [9]. OSHA's separate ammonia storage and handling standard, 29 CFR 1910.111, does not apply to refrigeration plants where ammonia is used solely as a refrigerant [10].
Calculate it yourself
Terms in this article
Sources
- 40 CFR Part 82, Subpart F – Recycling and Emissions Reduction (Section 608) – eCFR
- 40 CFR Part 84 – Phasedown of Hydrofluorocarbons (AIM Act) – eCFR
- US EPA – Section 608 of the Clean Air Act
- Federal Register, 26 May 2026 – Technology Transitions reconsideration, final rule (FR Doc. 2026-10387, 91 FR 31284)
- US EPA – Technology Transitions final rule fact sheet (May 2026)
- ASHRAE – Standards 15 and 34
- eCFR – 40 CFR 84.54 Restrictions on the use of certain HFCs (Technology Transitions)
- CARB – High-GWP Refrigerant Program (17 CCR 95371 ff.)
- OSHA – 29 CFR 1910.119 Process safety management of highly hazardous chemicals, Appendix A – eCFR
- OSHA – 29 CFR 1910.111 Storage and handling of anhydrous ammonia – eCFR