A federal appeals court on Friday rejected the Environmental Protection Agency’s attempt to abandon a Biden-era rule that sets tough standards for deadly soot pollution.

The unanimous ruling by a three-judge panel is a setback for the Trump administration's deregulatory agenda and its repeated efforts to boost coal.

The decision by the U.S. Court of Appeals for the District of Columbia Circuit leaves intact, for now, a tighter standard set in 2024 on pollution from coal-fired power plants, factories and other industrial sources.

The EPA under President Donald Trump asked the appeals court last year to invalidate the Biden-era rule, arguing that the agency under previous leaders had exceeded its statutory authority and acted unreasonably by failing to consider costs to businesses affected by the rule.

The court denied the Trump administration's request, saying in a decision written by Senior Judge Douglas Ginsburg that the agency's arguments “lack merit."

The ruling leaves in place an annual ⁠limit of 9 micrograms of fine particle pollution — often called soot — per cubic meter of air, down from 12 micrograms established more than a decade ago. The EPA rule sets an air quality level that states and counties must achieve in the coming years to reduce particle pollution from power plants, vehicles, industrial sites and wildfires.

The EPA's bid to walk away from the Biden-era rule came in response to a lawsuit by 25 Republican-led states and a host of business groups that attempted to block the 2024 rule in court. A suit led by attorneys general from Kentucky and West Virginia argued the EPA rule would raise costs for manufacturers, utilities and families and could block new manufacturing plants.

The EPA under Biden had said the tighter limits would avoid more than 800,000 ‌cases ⁠of asthma symptoms, 2,000 hospital visits and 4,500 premature deaths.scientist for the NRDC.