EPA used litigation to circumvent Clean Air Act rulemaking, seeking to vacate Biden PM2.5 soot standard

On November 25, 2025, the Trump EPA, led by Administrator Lee Zeldin, filed a brief in the U.S. Court of Appeals for the D.C. Circuit asking the court to vacate the Biden-era National Ambient Air Quality Standard for fine particulate matter (PM2.5). The EPA "confess[ed] error" in defending the rule, asking the court to vacate it by February 7, 2026—a move that would revert air quality standards to the Obama-era level of 12 micrograms per cubic meter and eliminate protections projected to prevent 4,500 annual premature deaths, 2,000 hospital visits, and 800,000 asthma cases by 2032.

The Clean Air Act requires EPA to set air quality standards "requisite to protect the public health" with an "adequate margin of safety." When the EPA changes those standards, the law mandates notice-and-comment rulemaking: the agency must publish its proposed rule, allow the public 60+ days to comment, document and respond to all significant comments, and issue a reasoned written explanation of its final decision. This process forces transparency. The public—and Congress—can see why a standard is changing. Regulated industries must justify their positions in the record. Courts can review whether the agency followed the law.

The EPA is circumventing this process by asking a court to vacate the rule through litigation. By admitting "error" in court rather than going through formal rulemaking, the EPA avoids publishing a Notice of Proposed Rulemaking, avoids the comment period, avoids documenting its reasoning, and avoids the statutory requirement to respond to public input. The court becomes a tool to accomplish a regulatory change without the accountability Congress built into the Clean Air Act. This is executive overreach camouflaged as litigation strategy: using one branch (courts) to bypass the procedural requirements of another branch (Congress's statutory mandates).

The decision follows EPA Administrator Zeldin's public pledge to roll back the PM2.5 rule as part of the administration's deregulatory agenda, signaling that the litigation position reflects political preference, not scientific judgment. The bypassed rulemaking process would have required the EPA to justify, in writing, why it was abandoning a health protection standard—a burden the agency evidently wanted to avoid.