On August 18, 2026, a unanimous panel of the U.S. Court of Appeals for the D.C. Circuit upheld the 2024 designation by the U.S. Environmental Protection Agency (EPA) of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund). (See Chamber of Commerce of the United States of America, et al. v. EPA, No. 24-1193 (D.C. Cir. Aug. 18, 2026).)

The decision leaves EPA’s PFOA and PFOS hazardous substance designations in place and provides guidance on the scope of EPA’s authority to make future hazardous substances designations under CERCLA Section 102(a). The decision also likely resolves a challenge to the rule that has spanned two presidential administrations. After taking office, the Trump administration had obtained an abeyance of the litigation challenging the Biden-era rule while EPA reconsidered its position. In September 2025, EPA informed the court that it had decided to retain the designations, while signaling that it would work with Congress and industry to address CERCLA liability concerns for “passive receivers.” The litigation then resumed, with the current Administration defending the rule.

Reprinted courtesy of Ashleigh K. Myers, Pillsbury, Amanda G. Halter, Pillsbury, Jillian Marullo, Pillsbury and Anthony B. Cavender, Pillsbury

Ms. Myers may be contacted at ashleigh.myers@pillsburylaw.com
Ms. Halter may be contacted at amanda.halter@pillsburylaw.com
Ms. Marullo may be contacted at jillian.marullo@pillsburylaw.com
Mr. Cavender may be contacted at anthony.cavender@pillsburylaw.com