Overview
- A three-judge panel of the U.S. Court of Appeals for the D.C. Circuit unanimously rejected the EPA’s request to walk back the Biden-era 2024 fine-particle (PM2.5) standard, saying the agency’s arguments lacked merit.
- The ruling keeps the annual limit at 9 micrograms per cubic meter, down from the previous 12 µg/m3 level, so the tighter standard remains legally operative for states and counties to meet.
- The Trump administration’s EPA had asked to invalidate or abandon the rule after 25 Republican-led states and industry groups sued, arguing the standard overstepped the agency’s authority and would impose large costs.
- The Biden EPA estimated the 2024 limit would prevent hundreds of thousands of asthma cases, about 2,000 hospital visits and roughly 4,500 premature deaths, and environmental groups hailed the decision as a win for public health.
- The ruling is a legal setback for the administration’s rollback agenda and leaves open potential next steps including further appeals, EPA implementation plans by states, and renewed litigation from the plaintiffs.