Attorney General Charity Clark has joined a coalition of 20 attorneys general in submitting a comment letter opposing the U.S. Environmental Protection Agency’s (EPA) proposed rule that would relax certain restrictions on hydrofluorocarbons (HFCs). HFCs are chemicals commonly used in refrigeration and cooling systems and are recognized as one of the fastest growing sources of greenhouse gas emissions both in the United States and globally.
The EPA’s proposal seeks to extend compliance deadlines by several years and increase allowable global warming potential (GWP) limits for refrigerants. The coalition argues that these changes would undermine existing regulations established under the American Innovation and Manufacturing Act of 2020 (AIM Act), which aims to reduce HFC usage by 85% by 2036.
According to the comment letter, “EPA fails to recognize how States and industry rely on the current regulations and that the new rule is contrary to law.”
HFCs were initially considered safer for the environment compared to chlorofluorocarbons (CFCs), which damage the ozone layer. However, later research revealed that HFCs have greenhouse effects hundreds to thousands of times greater than carbon dioxide over a century. Projections indicate that if unchecked, HFC emissions could contribute up to 0.44 degrees Celsius to global surface warming by 2100. Their high potency, increasing share in emissions, and relatively short atmospheric lifespan make reducing their use important for climate change mitigation.
The AIM Act was passed with bipartisan support in December 2020 and signed into law by President Trump. It provides a national framework for phasing out HFC production and consumption by about 85% over a fifteen-year period. Current regulations limit specific sectors—such as those using remote condensing systems for food refrigeration—to refrigerants with lower GWP values, typically between 150 and 300 depending on system type. The EPA’s proposed rule would raise this limit to 1,400 from January 1, 2026 through 2032. The attorneys general state that EPA has not provided enough evidence showing this relaxation aligns with the AIM Act’s goals.
Attorney General Clark joins counterparts from California, Connecticut, Delaware, the District of Columbia, Hawai’i, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New York, Oregon, Rhode Island, Wisconsin, Washington as well as the Chief Legal Officer of New York City in filing this opposition.
A copy of the comment letter can be found on the Vermont Attorney General’s website.
