Reported / Citable
Background
The Environmental Protection Agency determined under the Toxic Substances Control Act that nearly all uses of methylene chloride, a solvent used in products and industries including paint removal, furniture refinishing, refrigerant manufacturing, and electric-vehicle battery production, posed an unreasonable risk to human health. Its 2024 rule prohibited 40 of 53 identified conditions of use and subjected 13 remaining commercial or industrial uses to a workplace protection program, including exposure limits of 16 parts per million over 15 minutes and 2 parts per million over an eight-hour workday.
East Fork Enterprises, Epic Paint Company, and the American Chemistry Council challenged the rule, arguing that EPA exceeded its statutory authority and relied on unsupported scientific assumptions. The Sierra Club separately argued that EPA had not adequately protected fenceline communities, genetically susceptible people, and people allegedly exposed to ozone depletion associated with methylene chloride. The petitions were consolidated.
The Court’s Holding
The Fifth Circuit granted the industry petition, vacated the rule and its associated risk determination, and remanded to EPA. The court held that TSCA requires EPA to determine unreasonable risk separately for each condition of use, rather than deeming methylene chloride unreasonably risky “as a whole.” It also held that EPA unlawfully and without substantial evidence assumed workers did not use personal protective equipment, despite contrary evidence, OSHA requirements, and EPA’s earlier findings.
The court further held that EPA’s acute and chronic exposure limits were unsupported by substantial evidence and arbitrary and capricious. In the court’s view, EPA relied selectively on conservative assumptions and limited animal or human studies while inadequately addressing contrary human epidemiological evidence, existing OSHA limits, and significant public comments. The court also concluded that EPA had not adequately justified its near-total prohibition as necessary to eliminate unreasonable risk or sufficiently considered the economic and technical feasibility of alternatives.
The court denied the Sierra Club’s petition. It held that EPA could exclude fenceline exposure pathways when adequate scientific methods and reasonably available information were lacking, rejected the challenge concerning genetically susceptible populations because EPA had accounted for them through a conservative population estimate, and found no standing for the ozone-depletion claim because the asserted injury rested on an attenuated and speculative causal chain.
Key Takeaways
- TSCA requires EPA to evaluate unreasonable risk by individual condition of use; it does not authorize a blanket “whole chemical” determination.
- EPA must account for personal protective equipment when the evidence shows that its use is an actual or reasonably foreseeable condition of use.
- Exposure limits and use prohibitions must rest on the full rulemaking record, including contrary studies and significant public comments, under TSCA’s demanding substantial-evidence standard.
- After finding unreasonable risk, EPA may regulate only to the extent necessary and must consider benefits, economic consequences, and reasonably available, technically and economically feasible alternatives.
Why It Matters
The decision sharply limits EPA’s discretion when regulating chemicals under TSCA. It requires use-specific risk findings, meaningful consideration of real-world workplace protections, and a record-based explanation connecting scientific evidence to the statutory threshold of “unreasonable risk.”
The ruling also emphasizes that TSCA is not a zero-risk statute. On remand, EPA may regulate methylene chloride again, but it must develop legally valid risk determinations and justify each restriction as no broader than necessary.