Special thanks to Quan Nguyen for his assistance in writing this advisory.
On September 15, 2026, the Fifth Circuit unanimously granted a petition for review challenging the Environmental Protection Agency’s (EPA) 2024 final rule prohibiting all consumer uses and most industrial uses of methylene chloride. The court vacated the rule and the EPA’s unreasonable-risk determination and remanded the matter to the agency for further proceedings.
The Fifth Circuit also denied a separate challenge seeking stricter regulation of the chemical.
The decision could have lasting implications for the EPA’s administration of TSCA, including its approach to future risk evaluations and risk-management regulations.
How the EPA’s Regulation of Methylene Chloride Evolved
Congress enacted TSCA in 1976, authorizing the EPA to regulate chemicals in commerce that the agency determines pose “an unreasonable risk of injury to health or the environment.”
In 2016, Congress enacted the Frank R. Lautenberg Chemical Safety for the 21st Century Act, significantly amending TSCA and requiring the EPA to conduct priority risk evaluations for certain chemicals. The amendments allowed the EPA to bypass that new evaluation process and proceed directly to rulemaking for risk evaluations the agency had completed before 2016, including its evaluation of methylene chloride.
Methylene chloride is a commonly used solvent found in adhesives, automotive products, and paint removers. In 2019, the EPA issued a final rule prohibiting the use of methylene chloride in consumer paint and coating removal. In 2024, the EPA went further, issuing a final rule prohibiting 40 of the 53 identified conditions of use, including all consumer products containing methylene chloride.
Conditions of use can arise at any stage of a chemical’s life cycle, from manufacturing to disposal. The number and types of conditions of use vary by chemical.
Under TSCA, “conditions of use” are “the circumstances under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of.”
The Fifth Circuit’s Four Key Holdings
The EPA must evaluate each condition of use separately
The Fifth Circuit ruled that TSCA requires the EPA to evaluate unreasonable risk separately for each condition of use of a chemical substance.
The EPA had instead made a single determination that methylene chloride as a whole posed an unreasonable risk, despite finding that six uses posed no unreasonable risk. The court concluded that the agency lacked authority to make a chemical-wide determination rather than evaluate each condition of use separately.
The EPA must account for evidence of PPE use
The court found that the EPA violated TSCA by assuming in its risk evaluation that workers handling methylene chloride did not use personal protective equipment (PPE) despite the evidence to the contrary.
The court ruled that PPE is a significant “condition of use” that directly affects how a chemical substance is manufactured, processed, or distributed. The EPA therefore may not disregard proven or reasonably foreseeable worker safeguards based on speculation that some employers or employees may fail to follow them.
“Unreasonable risk” does not mean “zero risk”
The Fifth Circuit held that TSCA’s “unreasonable risk” standard cannot be interpreted to mean “zero risk.”
Instead, the court held that the “unreasonable risk” standard provides a prudential baseline for the EPA’s risk assessments. It distinguished TSCA’s “unreasonable risk” standard from the precautionary principles in some other environmental statutes, which may treat any risk as unreasonable.
The court found that the EPA’s approach was more conservative than TSCA permits. In assessing “unreasonable risk,” the EPA must use the best available science and all the relevant data it has to balance the benefits of regulation against its potential economic harms.
The EPA may regulate only “to the extent necessary”
The Fifth Circuit found that the EPA exceeded its statutory authority under TSCA, which requires the agency to regulate a chemical substance only “to the extent necessary” so that it no longer presents an unreasonable risk.
The court concluded that the EPA failed to adequately consider other practicable, economically feasible alternatives before prohibiting 40 of the 53 identified conditions of use for methylene chloride. The agency also improperly relied on uncertainty about whether companies could comply with less restrictive regulations to justify the prohibitions.
What the Decision Means for Regulated Companies
Since Congress amended TSCA in 2016, stakeholders have debated whether the EPA must evaluate a chemical’s risk as a whole or assess each condition of use separately. As the first appellate decision to address the issue, the Fifth Circuit’s decision provides important guidance for future TSCA rulemakings.
The ruling also underscores the evidence the EPA must consider in making unreasonable risk determinations, including evidence that workers use PPE. Companies manufacturing, supplying, or using chemicals regulated by TSCA should document conditions of use and the use of PPE and other measures in place to reduce potential risks to employees.
If you have any questions, or would like additional information, please contact one of the attorneys on our Environmental, Land Use & Natural Resources team.
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