States oppose proposals to weaken AIM Act
26th November 2025
USA: A multi-state coalition of 19 attorney generals are amongst those supporting a comment letter opposing the US EPA’s proposals to weaken rules to phase down the use of HFCs.
Lauren Sanchez, chair of the California Air Resources Board (CARB), is leading the coalition seeking to retain the provisions of the US AIM Act, and its intention to phase down HFCs by 85% by 2036.
The electronic submission to the US Environmental Protection Agency is supported by the attorney generals of Massachusetts, California, Colorado, Connecticut, Delaware, Hawaiʻi, Illinois, Maine, Maryland, Michigan, Minnesota, Nevada, New Jersey, New York, Oregon, Rhode Island, Vermont, Wisconsin, Washington, the District of Columbia, and the chief legal officer of the City of New York (together, State and Local Governments). Together they oppose the new proposals, claiming they would weaken important federal regulations transitioning the United States away from the use of HFCs.
The AIM Act was originally passed into law in December 2020. It proposes a timetable of bans on higher GWP refrigerant gas in specific equipment. For instance, currently, new remote condensing systems are limited to using refrigerants with 150 to 300 GWP, depending on the system. EPA’s proposed rule would raise the maximum GWP of the refrigerants that could be used to 1,400 from January 1, 2026, until 2032. The new proposals would also eliminate the January 1, 2026, installation deadline for the sale of residential and light commercial systems using refrigerants with a GWP above 700.
As well as conflicting with the intentions of the AIM Act, the letter describes the proposed new rule as being “arbitrary and capricious”. The reasons given to support it, the letter says, are contradicted by the evidence. It also claims that the EPA has failed to meaningfully analyse the costs and benefits of the proposed rule, let alone explain why the extensive analysis supporting the existing rule is no longer operative.
In addition, it maintains that the proposed rule upsets the reliance interests of parties that have complied with the current rule in good faith. It accuses the EPA’s proposal that a final rule take effect 30 days after its publication as being unlawful under the plain language of the AIM Act. Finally, it says that the EPA’s limited analysis of the proposed new rule’s economic and climate effects “frustrates meaningful understanding” of the rule and constitutes procedural error.
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