Image Source: Reuters. The headquarters of the United States Environmental Protection Agency (EPA) in Washington, DC

A coalition of 18 Democratic-led states, together with Washington, D.C., and New York City, has filed a lawsuit against the U.S. Environmental Protection Agency (EPA), challenging a new federal rule that delays the phase-out of hydrofluorocarbons (HFCs), powerful greenhouse gases widely used in refrigeration and air-conditioning systems.

The lawsuit, filed before the U.S. Court of Appeals for the District of Columbia Circuit, accuses the Trump administration of unlawfully weakening climate protections by extending the time businesses may continue using high-emission refrigerants. The plaintiffs argue that the EPA's decision violates federal law and undermines Congress' efforts to reduce emissions that contribute significantly to global warming.

The case marks another major legal confrontation between Democratic-led states and President Donald Trump's administration as disputes over environmental regulation continue to dominate U.S. courts.

The challenged EPA rule

At the centre of the dispute is the EPA's interpretation of the American Innovation and Manufacturing (AIM) Act, a bipartisan law enacted in 2020 to gradually phase down the production and use of hydrofluorocarbons by 85% before 2036. Hydrofluorocarbons are commonly used in commercial refrigeration, air-conditioning and cooling equipment. Although they do not damage the ozone layer like earlier refrigerants, they possess an exceptionally high global warming potential, with some HFCs trapping hundreds or even thousands of times more heat than carbon dioxide.

To accelerate the transition to environmentally safer alternatives, the AIM Act established strict deadlines for replacing HFC-based equipment across several industries. However, the EPA recently issued a final rule extending compliance deadlines for certain commercial refrigeration systems until 2032, arguing that additional flexibility would reduce regulatory costs and ease the burden on manufacturers and businesses.

States allege violation of federal law

The plaintiffs contend that the EPA exceeded its statutory authority by creating exemptions that Congress never authorised.

According to the petition, the agency's decision allows businesses to continue installing or operating equipment that relies on high-emission refrigerants well beyond the timetable established by the AIM Act, frustrating the legislation's purpose of rapidly reducing greenhouse gas emissions.