On March 21, 2024, the U.S. Court of Appeals for the Fifth Circuit vacated two EPA orders prohibiting Inhance Technologies LLC from manufacturing or processing PFAS during the fluorination of its plastic containers. The two EPA orders were part of efforts EPA has taken since confirming the presence of PFAS in a pesticide that had been stored in containers fluorinated by Inhance. The Court found that EPA had exceeded its authority under Section 5 of the Toxic Substances Control Act (TSCA), which allows EPA to regulate any “significant new use” of a chemical substance. In so doing, the Court rejected EPA’s argument that a “significant new use” is any use previously unknown to EPA – commenting that EPA’s interpretation “defies common sense” – and found that EPA “may not contort the plain language of TSCA’s Section 5 to deem a forty-year-old ongoing manufacturing process a ‘significant new use’ subject to the accelerated regulatory process provided by that part of the statute.” The Court’s opinion can be found here.