R-454B
Opteon XL41
R-454B is a lower-GWP refrigerant blend used in many new U.S. home air conditioners and heat pumps; EPA lists its global warming potential as 470 and its ASHRAE safety class as A2L.
EPA’s Significant New Alternatives Policy (SNAP) program lists R-454B as acceptable, subject to use conditions, for new residential and light commercial air conditioning and heat pump equipment. With a global warming potential of 470, it falls under the limit of 700 that applies to new systems made or imported from January 1, 2025.
It is an A2L refrigerant: lower toxicity and lower flammability. EPA’s A2L listings require equipment built to UL Standard 60335-2-40, Edition 3, so R-454B goes into equipment designed for it, not into systems built for R-410A.
In its 2026 final rule, EPA noted that the rollout of equipment using compliant refrigerants, including R-454B, saw unexpected supply issues, and that some contractors had difficulty getting R-454B to charge new units.
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