Fifth Circuit Vacates EPA’s Methylene Chloride Rule and Limits “Whole Chemical” Risk Findings Under TSCA
Fifth Circuit Vacates EPA’s Methylene Chloride Rule and Limits “Whole Chemical” Risk Findings Under TSCA
On 15 September 2026 the U.S. Court of Appeals for the Fifth Circuit vacated the Environmental Protection Agency’s 2024 risk-management rule for methylene chloride and the underlying unreasonable-risk determination. In East Fork Enterprises, Inc. v. EPA, a unanimous panel held that EPA lacked authority to make a “whole chemical” risk finding and must instead evaluate unreasonable risk in relation to specific conditions of use. The court granted industry petitions for review, denied a separate challenge seeking stricter regulation, and remanded the matter to the agency. The decision reaches beyond a single solvent: it constrains how EPA may apply Section 6 of the Toxic Substances Control Act (TSCA) to existing chemicals more broadly.
What the Vacated Rule Had Done
EPA’s 2024 rule had prohibited 40 of 53 evaluated conditions of use for methylene chloride and placed the remaining industrial and commercial uses under a Workplace Chemical Protection Program that included exposure limits, monitoring, and required protective equipment. The rule rested on a determination that methylene chloride presented an unreasonable risk of injury as a whole, rather than solely through particular uses. That “whole chemical” framing allowed the agency to impose broad prohibitions and controls once it concluded the substance itself posed unreasonable risk.
The Court’s Core Holding
The Fifth Circuit rejected that approach. It held that TSCA requires EPA to assess unreasonable risk in relation to the chemical’s conditions of use. A single, substance-wide determination that then justifies sweeping restrictions across many uses was found to exceed the agency’s statutory authority. The court also addressed related issues, including how EPA must account for personal protective equipment and the constraints that apply when the agency selects measures to eliminate unreasonable risk. The result is a remand that forces EPA to revisit both the risk determination and the risk-management rule under a narrower, use-specific framework.
Implications for Other TSCA Existing-Chemical Rules
Methylene chloride was one of the early high-priority substances regulated under the amended TSCA. EPA has applied similar analytical approaches to other chemicals in the risk-evaluation and risk-management pipeline. By limiting the “whole chemical” method, the Fifth Circuit decision gives industry petitioners a stronger basis to challenge rules that rest on substance-wide risk findings rather than condition-of-use analysis. Future evaluations and rules may need more granular use-by-use reasoning, more explicit treatment of PPE and existing workplace controls, and clearer linkage between identified risks and the chosen regulatory measures.
Immediate Practical Effects
The vacatur removes the 2024 prohibitions and Workplace Chemical Protection Program requirements for methylene chloride that depended on the invalidated determination. Companies that had been preparing to exit or heavily restrict uses now face a period of regulatory uncertainty while EPA reconsiders the file on remand. Downstream users in applications that had been slated for prohibition regain short-term operating room, but they should not assume the substance is permanently clear of further regulation. EPA retains authority to re-evaluate and re-issue a rule consistent with the court’s interpretation.
Broader TSCA Litigation Landscape
The decision adds to a growing body of case law testing how EPA implements the 2016 TSCA amendments. Questions about the scope of “unreasonable risk,” the role of conditions of use, the weight given to PPE, and the stringency of risk-management measures are now live appellate issues. Other pending or forthcoming rules for high-priority chemicals may attract similar challenges if they rely on analytical approaches the Fifth Circuit has rejected. Regulated companies and trade associations are likely to cite the opinion in comments and litigation on those files.
Outlook
The Fifth Circuit’s vacatur of the methylene chloride rule marks a significant judicial check on EPA’s existing-chemical program under TSCA. By requiring risk determinations to be tied to conditions of use rather than to the chemical as a whole, the court has raised the analytical bar for future Section 6 rules. EPA must now decide how to redo the methylene chloride evaluation and whether to adjust its methodology for other substances already in the pipeline. For the chemical industry the decision provides temporary relief on one high-profile rule and a clearer statutory boundary for the next round of risk management—while leaving open the possibility that use-specific restrictions will still emerge once the agency completes its remand work.
Sources
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