This guide is for contractors who install and service residential air conditioning (AC) and heat pump systems. It covers the Technology Transitions restrictions from the U.S. Environmental Protection Agency (EPA). It also covers the May 2026 final rule that changed them. It then looks at some refrigerants EPA lists for new systems and the safety standards EPA cites. It ends with Section 608 technician certification. For the homeowner's side of the same rules, see our guide to what the R-410A phase-out means for your air conditioner.
EPA's summary tables carry a note. It says the tables are for information only and should not be relied on for compliance. It points readers to 40 CFR Part 84, Subpart B for full details. This guide quotes both the tables and the regulation.
The January 1, 2025 installation compliance date
EPA last updated its Technology Transitions table on August 28, 2026. The table says that starting January 1, 2025, certain technologies may no longer use high global warming potential (GWP) hydrofluorocarbons (HFCs) or HFC blends. It says the bans cover making, distributing, selling, installing, importing and exporting products that contain restricted HFCs. They also cover installing new systems that use restricted HFCs.
The table lists a GWP limit of 700 for residential and light commercial AC and heat pump systems. Examples include mini-splits and unitary systems. That row gives an installation compliance date of January 1, 2025. Footnote 5 reads:
EPA is restricting the installation of new field-assembled systems. Components used to repair existing systems are not subject to these restrictions.
Footnote 6, attached to the residential systems row, reads:
No installation compliance date for systems where all specified components were manufactured or imported prior to January 1, 2025. Refer to the Technology Transitions Reconsideration Rule for additional details.
The restriction itself is in 40 CFR 84.54(c)(1). It applies to residential or light commercial AC or heat pump systems that use a regulated substance, or a blend containing one, with a GWP of 700 or greater. The regulation says new systems of this kind may still be installed if all specified components of the system were made or imported before January 1, 2025. The same paragraph makes an exception for variable refrigerant flow (VRF) systems. This guide does not cover VRF dates.
Self-contained products are in a separate EPA table. They include window units and portable room air conditioners. That table lists the same 700 limit and a January 1, 2025 compliance date for manufacture and import. A footnote says sale, distribution and export of these products is banned three years after the manufacture and import compliance date.
What EPA's May 2026 final rule changed
An earlier EPA rule set a deadline for installing older equipment. EPA's regulatory actions page says that rule allows inventory of higher-GWP HFC equipment made or imported before January 1, 2025, to be installed until January 1, 2026.
On October 3, 2025, EPA proposed changes to several Technology Transitions restrictions. These included the restrictions for residential and light commercial AC and heat pump systems. The final rule was published in the Federal Register on May 26, 2026, at 91 FR 31284. In it, EPA said it was finalizing, as proposed, the removal of the deadline for installing these systems. This applies when the equipment was made in the United States or imported into it before January 1, 2025. The rule states, "This final rule is effective on July 27, 2026."
EPA's May 2026 fact sheet says the rule removes the January 1, 2026, installation compliance date for some equipment. It applies to equipment using refrigerants above the 700 limit that were made in the United States or imported into it before January 1, 2025. The fact sheet also says the rule allows pre-2025 inventory of air conditioning systems to be installed until supply runs out.
| Date | What happened | Source |
|---|---|---|
| January 1, 2025 | Installation compliance date for new residential and light commercial AC and heat pump systems, with a GWP limit of 700. Repair components are not restricted. Systems built from pre-2025 components now have no date | EPA sector table |
| October 3, 2025 | EPA publishes its proposal to revise the restrictions | 91 FR 31284 |
| January 1, 2026 | Earlier deadline for installing pre-2025 inventory, later removed by the 2026 final rule | EPA regulatory actions |
| May 26, 2026 | Final rule published in the Federal Register | 91 FR 31284 |
| July 27, 2026 | Final rule takes effect | 91 FR 31284 |
Our consumer guide to the R-410A phase-out covers legal challenges filed against the 2026 rule. We did not re-check those cases for this article.
Refrigerants EPA lists for new residential systems
EPA has a program called the Significant New Alternatives Policy (SNAP). It lists refrigerants for residential and light commercial AC and heat pumps. EPA's SNAP questions and answers use A2L for "lower flammability" refrigerants. EPA last updated the SNAP page on March 19, 2026. It includes these rows for new equipment:
| Refrigerant (as EPA lists it) | GWP | ASHRAE safety class | SNAP status |
|---|---|---|---|
| R-454B | 470 | A2L | Acceptable with Use Conditions |
| HFC-32 | 675 | A2L | Acceptable with Use Conditions |
| R-410A | 2,090 | A1 | Acceptable |
Global warming potential of R-410A and two A2L refrigerants EPA lists
- R-410A (A1)2,090 GWP
- EPA limit for new systems700 GWP
- HFC-32 (A2L)675 GWP
- R-454B (A2L)470 GWP
A SNAP listing is separate from the Technology Transitions limit. The SNAP page says many substitutes that are acceptable under SNAP may be restricted under the Technology Transitions Program. It adds that SNAP information published in the Federal Register overrides all information on the page.
EPA's frequent questions on HFCs address a broken R-410A outdoor unit. They ask whether you can replace it with one that uses a lower-GWP refrigerant. EPA's answer says the 2023 Technology Transitions Rule does not address this issue, but it may be possible depending on the circumstances. EPA adds that its SNAP program and industry standards ban flammable or mildly flammable refrigerants, such as HFC-32 or R-454B, in systems not designed to use them.
In the 2026 final rule, EPA also wrote about R-454B supply in the field. It said there was enough R-454B, but there were challenges getting it to contractors and technicians in service cylinders. EPA said this led to R-454B scarcity in some regions. It said some contractors and technicians had trouble getting R-454B in the field to charge these units during installation. The passage does not name the regions.
Safety standards EPA cites for A2L systems
EPA's SNAP questions and answers say, "EPA's listings for lower flammability (A2L) refrigerants in SNAP Rules 23 and 25 require compliance with UL Standard 60335-2-40 Edition 3." The page adds that new equipment certified to UL 60335-2-40 Edition 4 may be installed or made as long as it also meets the requirements of UL 60335-2-40 Edition 3.
The same page also covers Standard 15 of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). EPA says it believes following this standard will ensure the safety of technicians and the people in the building. It adds that the standard applies to the use of alternative refrigerants.
EPA says it treats flammability as one of many factors when it screens risks under SNAP. It also says it has listed flammable refrigerants as acceptable. Where appropriate, EPA includes use conditions to ensure safety. We did not review the text of SNAP Rules 23 and 25, so this guide does not list their specific use conditions, such as charge limits or labeling.
SNAP Proposed Rule 27
EPA's SNAP rules page describes Proposed Rule 27. Among its proposed changes, the rule would update existing use conditions for eight refrigerants in residential and light commercial AC and heat pumps. It would also list three refrigerants as acceptable for that equipment, subject to use conditions. These are proposals, not final rules. As of October 2026, we did not see a final Rule 27 on that page. The page also did not name the refrigerants.
Section 608 technician certification
EPA last updated its Section 608 certification page on July 15, 2026. The page cites EPA rules under Section 608 of the Clean Air Act. These rules are found at 40 CFR Part 82, Subpart F. It says those rules require certification for technicians who maintain, service, repair or dispose of equipment that could release refrigerants into the air. The page says technicians must pass an EPA-approved test to earn this certification. Each test is specific to the type of equipment the technician wants to work on. An EPA-approved certifying organization must give the tests.
EPA lists these certification types:
- Type I is for servicing small appliances.
- Type II is for servicing or disposing of high- or very high-pressure appliances, except small appliances and MVACs.
- Type III is for servicing or disposing of low-pressure appliances.
- Universal is for servicing all types of equipment.
The page we read does not say which type covers residential split systems. EPA says, "Section 608 Technician Certification credentials do not expire." It also says apprentices do not need certification as long as a certified technician supervises them closely and continually.
EPA's sales restriction page says only Section 608 certified technicians can buy refrigerants meant for stationary refrigeration and air-conditioning equipment. The page says employers of these technicians can generally buy refrigerant too. To do so, they must give the wholesaler written proof that they employ at least one properly certified technician.
Our guide to HVAC licensing in Arizona, Washington, Texas, Florida and Ohio covers state rules. Our HVAC job outlook covers how the U.S. Bureau of Labor Statistics (BLS) describes training. Our guide to HVAC technician pay covers May 2025 wages.