If you've replaced an air conditioner or heat pump recently — or you're about to — the refrigerant inside the new unit has changed. Since the start of 2025, manufacturers can no longer make or import residential equipment that uses R-410A. It's the biggest refrigerant shift since R-22 was phased out a decade ago, and it's driven by climate policy, not equipment performance.
The rule in one sentence
Under the American Innovation and Manufacturing (AIM) Act, the EPA's Technology Transitions rule restricts the use of high-global-warming-potential (GWP) hydrofluorocarbons. For residential and light commercial air conditioning and heat pumps, the cap is a GWP of 700, with a manufacture-and-import compliance date of January 1, 2025 ([EPA, Technology Transitions HFC Restrictions by Sector](https://www.epa.gov/hfcs/technology-transitions-hfc-restrictions-sector)). The prohibitions cover "the manufacture, distribution, sale, installation, import, and export of products containing restricted HFCs."
Why R-410A is on the way out
R-410A has been the standard residential refrigerant since about 2010. It's nonflammable (ASHRAE safety group A1) and performs well, but its GWP is roughly 2,088 — more than triple the 700 cutoff. The replacements aren't a single drop-in; they're a family of lower-GWP blends, most of them in the A2L safety group.
| Refrigerant | GWP (AR4) | Safety group | Typical use | Status |
|---|---|---|---|---|
| R-410A | ~2,088 | A1 (nonflammable) | Older ducted AC/HP, 2010–2024 | Restricted for new equipment |
| R-454B | ~466 | A2L | New ducted AC/HP | Primary R-410A replacement |
| R-32 | ~675 | A2L | Mini-splits, some unitary | Common in ductless |
| R-452B | ~698 | A2L | Some ducted AC/HP | Alternative replacement |
GWP values are AR4 100-year values as referenced under the EPA rule; safety groups per ASHRAE Standard 34.
A2L is not a retrofit.R-454B and R-32 are not drop-ins for an existing R-410A system. The change happens at equipment replacement — a new unit designed and listed for the new refrigerant — not at a service visit or a recharge.
What "A2L" actually means
Refrigerant safety groups are set by ASHRAE Standard 34. The "2L" means the refrigerant is mildly flammable but burns slowly and is hard to ignite — a deliberate tradeoff that cuts GWP sharply while staying usable in homes when the equipment is designed for it. A2L systems are held to stricter safety rules under ASHRAE 15.2 and UL 60335-2-40, including leak detection, reduced charge limits, and components rated for the refrigerant ([ASHRAE 15.2, 2022](https://www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20addenda/15_2_2022_c_20240329.pdf)).
One wrinkle — the reconsideration
EPA has signaled it may extend some of these dates. A "Technology Transitions Reconsideration" rulemaking is in progress, but EPA states plainly that "the current deadlines remain effective until modified through this rulemaking" ([EPA, Regulatory Actions for Technology Transitions](https://www.epa.gov/climate-hfcs-reduction/regulatory-actions-technology-transitions)). One adjustment is already final: for variable refrigerant flow (VRF) systems, higher-GWP equipment manufactured before January 1, 2026 may be installed through January 1, 2027 — longer for certain already-permitted projects.
What this means for you
- If your system is R-410A and working: keep it. The rule targets new equipment, not your existing charge. R-410A is still produced for service.
- When you replace after 2025: the new unit will use an A2L refrigerant. That's the new normal, and it's safe when installed to code.
- For technicians: A2L handling has real differences — DOT special permits for shipping, storage limits, and servicing best practices ([AHRI, Safe Refrigerant Transition](https://www.ahrinet.org/advocacy/safe-refrigerant-transition)).
Don't mix refrigerants.A system designed for R-410A must not be recharged with R-454B or R-32. Different pressures, different oil, different safety requirements. Always follow the nameplate.
Naming a specific refrigerant or manufacturer here is factual, not an endorsement. HVAC Zone Inc is a multi-brand dealer; the Information Hub is brand-neutral.
The bottom line
The A2L transition is the largest refrigerant change since R-22, it's here, and it's manageable. Existing R-410A systems aren't banned; new equipment simply uses a lower-GWP refrigerant that's held to stricter safety standards. Want help planning a replacement or understanding what's in your current system? Get in touch — we'll look at your actual setup, not sell you a brand.