The D.C. Circuit upheld an EPA rule covering PFOA and PFOS, preserving requirements and cleanup tools that may affect businesses connected to contaminated sites.
The unanimous three-judge panel denied five consolidated industry petitions on August 18, 2026.
Key Facts
- The ruling leaves EPA’s May 2024 final rule in effect.
- The rule covers PFOA and PFOS, including their salts and structural isomers, rather than every PFAS chemical.
- Businesses do not automatically owe cleanup costs because the chemicals appear at a site.
- EPA must make further site-specific decisions before seeking many cleanup costs.
What the court decided
The industry groups argued that EPA misread federal Superfund law and inadequately considered the rule’s costs, benefits and uncertainties.
EPA defended its authority and asked the court to deny the challenges.
Environmental and community groups, including Clean Cape Fear, participated in support of EPA.
Judge Patricia Millett wrote the opinion for Judges Gregory Katsas and Neomi Rao.
The panel ruled that the law allows designation when a substance may present substantial danger, without requiring certainty that every release will cause harm.
It also concluded that EPA gave adequate notice and reasonably addressed the rule’s expected costs, benefits and uncertainties.
The court therefore denied the petitions for review, leaving the existing rule in force.
What the rule does now
EPA published the final rule on May 8, 2024, and it took effect on July 8, 2024.
It designates PFOA and PFOS, including covered salts and structural isomers, as hazardous substances under the federal Superfund law.
PFAS is a much broader family of human-made chemicals, so the designation does not apply to the entire class.
The rule requires immediate reporting when a release of either covered chemical reaches one pound or more within a 24-hour period, the federal reportable quantity.
It also makes federal response, enforcement and cost-recovery tools available for releases involving the two chemicals.
EPA based the rule on evidence concerning the chemicals’ hazards, persistence, movement through the environment and potential for human exposure.
Cleanup costs are not automatic
The ruling does not determine that any named company contaminated a site or presently owes cleanup costs.
Future responsibility depends on the facts at a particular location and on whether a party fits one of Superfund’s covered categories.
Those categories can include certain owners, operators, parties that arranged for disposal or treatment, and transporters connected to a release or disposal.
Before EPA orders a response or the government seeks to recover cleanup costs, the agency may need to investigate the site, select a response and follow federal cleanup procedures.
Available defenses, cost allocation, enforcement choices and settlements can also affect what a particular party must pay.
The court stressed that these steps make cleanup and cost-recovery decisions contingent and site-specific.
Why the dispute matters
The designation can shift some qualifying cleanup costs from public funds to parties legally responsible for contamination.
Industry petitioners warned that the rule could produce large and uncertain costs. They said those costs could affect waste management and real estate transactions.
EPA maintained that the designation supports earlier cleanups and makes responsible parties bear appropriate costs while statutory protections remain available.
The panel-stage decision resolves the consolidated challenges.
