Fifth Circuit Vacates EPA's Methylene-Chloride Risk-Management Rule Under TSCA

On 15 September 2026, the US Court of Appeals for the Fifth Circuit vacated the US Environmental Protection Agency’s (EPA) 2024 methylene-chloride rule under Section 6 of the Toxic Substances Control Act (TSCA). The rule had prohibited most uses of methylene chloride—a volatile liquid chemical used widely and for many years in consumer and commercial applications—including all consumer uses, and imposed workplace controls on the limited commercial and industrial uses that remained. In East Fork Enterprises v. EPA, the court shot down EPA’s decision-making in the strongest terms, holding that EPA’s risk determination and rule were contrary to law, arbitrary and capricious, and unsupported by substantial evidence. The decision is the first appellate ruling on a risk-management rule issued under TSCA’s 2016 amendments.

In the 2024 rulemaking, EPA departed from its standard multiuse review of chemical risk and instead agglomerated all risks associated with all uses of the chemical under what it called its “whole chemical” approach. The court completely rejected this approach, holding that the language of TSCA requires EPA to assess unreasonable risk by individual condition of use instead of relying on risks associated with some uses to regulate all uses. Similarly, the court held that EPA failed to follow TSCA in assuming workers do not use personal protective equipment (PPE) where PPE use is relevant, reasonably foreseeable, and common. The court also dove deeply into the specific scientific information that EPA relied on to find that EPA had inappropriately rejected the conclusions of numerous scientific papers to support the exceptionally low exposure limits imposed by the rule. 

In essence, the court refused to defer to EPA’s factual findings, subjecting EPA’s scientific decision making to a deep and scathing review. The court emphasized that TSCA is not a zero-risk statute and that EPA may regulate a chemical only “to the extent necessary” to eliminate an identified unreasonable risk. The court stated that EPA must consider benefits, economic consequences, and, where restrictions substantially prevent a use, reasonably available technically and economically feasible alternatives. The court found that EPA had not adequately supported its near-complete prohibition or meaningfully assessed alternatives. Although the court denied the Sierra Club’s challenge seeking greater protections, it vacated the rule and remanded the matter to EPA. 

As EPA confronts the difficulties associated with regulating a number of emerging chemicals in different contexts, the court’s decision should encourage EPA to make its decisions strictly in compliance with the language of its controlling statutes only after a rigorous review of all available scientific information. Regulated entities should monitor EPA’s response, to confirm whether EPA meets the challenge laid down by the court.

We acknowledge the contributions to this publication from our law clerk, Janine LeChien.