TSCA Upheaval: Fifth Circuit Vacates EPA Methylene Chloride Rule

Some 15 months after oral argument on September 15, 2026, a unanimous panel of the U.S. Court of Appeals for the Fifth Circuit issued its decision on the final methylene chloride rule in East Fork Enterprises Inc v. EPA, No. 24-60227. The Environmental Protection Agency (EPA) adopted that rule under Section 6(a) of the Toxic Substances Control Act (TSCA).

The decision vacated the entire rule and is certain to affect other pending challenges to EPA risk management rules. It may also force EPA to make fundamental changes to how it conducts risk evaluations under Section 6(b) of TSCA. The court’s decision may mean that EPA must consider whether its final, draft, and in-process risk evaluations for multiple chemicals must be significantly revised, and whether it needs to revise its final, proposed, and in-process risk management rules. Unless successfully appealed further or rejected by other circuits, the methylene chloride case could upset EPA’s approach to Section 6 to the degree the earlier Fifth Circuit decision, Corrosion Proof Fittings v. EPA, 947 F.2d 1201 (1991), did.

Background on the Methylene Chloride Rule

EPA’s efforts to regulate methylene chloride under TSCA began before the 2016 amendments to TSCA. In 2019, the first Trump EPA published a narrow rule focused on methylene chloride’s uses in consumer paint and coating removal. The U.S. Court of Appeals for the Second Circuit rejected challenges to that rule. Labor Council for Latin American Advancement v. EPA, 12 F.4th 234 (2nd Cir. 2021). As for the remaining conditions of use (COUs), EPA took a step toward comprehensive methylene chloride regulation in 2020, publishing a final risk assessment (the 2020 Risk Determination) that considered 53 distinct conditions of use and found 47 of them to pose an unreasonable health risk.

The 2020 Final Risk Determination was one of the many regulatory actions that came under immediate scrutiny after the Biden administration took office. In 2021, the Biden EPA revisited, reconsidered, and ultimately scrapped the 2020 Risk Determination. EPA published a revised methylene chloride risk determination in 2022 (the 2022 Risk Determination).

Each risk determination was developed under a different analytical framework. EPA’s 2020 Risk Determination resulted from a procedure formalized in 2017, which required assessing the risk for each reasonably foreseeable COU for the chemical and assumed that workers adequately used personal protective equipment (PPE) in those circumstances. The 2022 Risk Determination abandoned both, choosing instead to evaluate risk for the chemical overall—the “whole chemical” approach, i.e., without regard for specific COUs—and disregarding the protective effects of PPE use in risk determinations. The Biden EPA eventually incorporated both of these policy changes as programmatic revisions to the 2017 procedural rule, which EPA finalized as a revised procedural rule in 2024.

The 2022 Risk Determination formed the basis of EPA’s risk management rule for methylene chloride (the 2024 Rule). The 2024 Rule effectively phases out all but 13 COUs across production, importation, and domestic contexts. The 2024 Rule justified its outright prohibitions on EPA’s assumption that the regulated community could not comply with stricter exposure limits. Each of the 13 remaining COUs faced stringent exposure limits.

Industry participants and environmental non-profit organizations sought judicial review of both the 2022 Risk Determination and the 2023 Rule. Hence, the East Fork litigation.

A Unanimous Panel Dismantles the 2022 Risk Determination and 2024 Rule

On September 15, 2026, the East Fork court issued its merits decision. The three-judge panel unanimously sided with industry petitioners, rejected all arguments made by an environmental non-profit organization, vacated both the 2022 Risk Determination and the 2024 Rule, and remanded both to EPA. The opinion’s key conclusions are summarized below.

TSCA Requires a Risk Determination for Each Anticipated Condition of Use

The panel first addressed and rejected EPA’s “whole chemical” approach. The court disagreed with EPA that TSCA Section 6 is ambiguous, holding instead that the statutory text is “clear” that EPA must assess risk for each condition of use. The panel also emphasized EPA’s 2017 procedural rule, noting that EPA’s departure from its prior approach required more explanation than a mere different interpretation of TSCA’s text. As a result, the panel held EPA’s “whole chemical” risk evaluation approach was unlawful.

EPA’s PPE Assumptions Must Have Substantial Evidentiary Support

The court next invalidated EPA’s other major deviation from the 2017 procedural rule: excluding PPE usage from its risk-evaluation analysis. The court first observed that the definition of “conditions of use” includes circumstances that are reasonably foreseeable or known, and that PPE usage is foreseeable given OSHA requirements and separate state regulatory regimes. The technical holding, however, was that EPA must consider PPE usage when determining risk if substantial record evidence shows PPE usage. Because commenters on the 2020 methylene chloride draft risk determination submitted evidence of adequate PPE usage, the panel found EPA’s assumption about PPE unsupported by substantial evidence in the record.

“Unreasonable Risk” Does Not Authorize Regulations Eliminating Risk

The court also sided with industry petitioners in concluding that EPA’s 2022 Risk Determination unlawfully collapsed TSCA’s “unreasonable risk” standard into a zero-risk precautionary principle by treating virtually any risk as “unreasonable.” The panel characterized “unreasonable risk” as a “prudential baseline” standard rather than a factual finding owed deference due to the agency’s expertise. The panel concluded that under Loper Bright, it must examine EPA’s substantive conclusions about “unreasonable” risk to determine whether EPA’s findings had sufficient evidentiary support to satisfy the prudential baseline. The panel then proceeded to examine – and invalidate – the following components of the 2022 Risk Determination and the 2024 Rule:

• The opinion heavily criticized the methodology underlying EPA’s acute-exposure and chronic-exposure limitations. The panel emphasized that each limitation relied on a single study, effectively ignoring contradictory data posed by other relevant epidemiological studies. The panel also highlighted a relatively large gap between the rule’s exposure limits and OSHA’s analogous limits.
• The court next took issue with the functional ban on most uses of methylene chloride. The opinion emphasized that EPA’s authority to mitigate risk does not support categorical bans unless the administrative record supplies substantial evidence that a functional ban is “necessary” to eliminate actual, identified, unreasonable health risks.
• Finally, the panel concluded that EPA neglected to meaningfully consider technologically and economically feasible alternatives to outright bans on methylene chloride uses.

The Fifth Circuit entered judgment on September 15, 2026, which means the parties have until October 30 to petition for rehearing or rehearing en banc, and until December 14 to petition for certiorari.

Commentary

The court’s decision is likely to influence other cases challenging risk management rules. It is a binding precedent for the Fifth Circuit, where the challenge to the perchloroethylene rule is pending. It is not binding, but it may prove influential in the trichloroethylene case pending in the Third Circuit (currently being briefed) and the carbon tetrachloride case pending in the Eighth Circuit (currently stayed). Petitioners in the trichloroethylene case have already notified the court of the East Fork Enterprises decision.

The decision could also disrupt EPA’s progress toward finalizing risk evaluations and promulgating risk management rules. EPA may need to reopen final risk evaluations and revise draft risk evaluations that are based on statutory interpretations and risk evaluation processes that the Fifth Circuit has now declared unlawful. It may want to hold back on further risk management rulemaking until after it has reconsidered the underlying risk evaluations. Any substantial delays in publishing final risk evaluations may require EPA to petition for additional extensions to the deadlines outlined in the 2024 consent decree rendered in Community in-Power and Development Ass’n v. EPA, No. 1:23cv2715 (D.D.C.). They may also make it increasingly difficult for EPA to finalize risk management rules during the remainder of the Trump administration.

Beveridge & Diamond is available to assist in preparing comments on risk evaluations and rulemakings, legal challenges, and helping companies navigate the constantly evolving TSCA regulatory landscape.

Beveridge & Diamond’s Chemicals Regulation practice group and Chemicals industry group provide strategic, business-focused advice to the global chemicals industry. We have a subscription service that tracks PFAS developments nationwide. We work with large and small chemical and products companies whose products and activities are subject to EPA’s broad chemical regulatory authority under TSCA and state chemical restrictions. Our Consumer Products and Product Stewardship, Global Supply Chains practices work with U.S. and multinational companies that make, distribute, transport, or sell consumer products in a hyper-competitive and evolving consumer goods market. We help identify, understand, and comply with complex regulatory requirements throughout the product lifecycle. For more information, please contact the authors.