The U.S. Court of Appeals for the Fifth Circuit has vacated the Environmental Protection Agency's rule restricting methylene chloride under the Toxic Substances Control Act (TSCA), dealing a significant setback to the agency's chemical risk-management program and to the regulatory certainty that downstream users of the solvent had been operating under.

The ruling, reported by JD Supra under the headline "TSCA Upheaval: Fifth Circuit Vacates EPA Methylene Chloride Rule," removes — at least for now — the federal restrictions EPA finalized to protect workers from methylene chloride exposure. The court found the rule deficient on legal grounds and vacated it rather than remanding without vacatur, meaning the restrictions do not remain in place while EPA works on a response.

For the solvent-recovery and chemical-distribution sectors, the decision has immediate operational significance. Methylene chloride, also known as dichloromethane, is a widely used industrial solvent applied in paint and coating removal, pharmaceutical manufacturing, adhesives and chemical processing. EPA's rule had imposed a compliance architecture on those uses — workplace protections, phase-outs and use prohibitions — that facilities have been planning around since the rule was finalized. Vacatur resets that baseline.

The case is the latest flashpoint in the broader fight over how EPA exercises the risk-evaluation and risk-management authorities Congress expanded in the 2016 Frank R. Lautenberg Chemical Safety for the 21st Century Act amendments to TSCA. Industry petitioners challenged the methylene chloride rule on multiple grounds, arguing EPA had overstepped its statutory authority in how it assessed and addressed occupational exposures. The Fifth Circuit agreed that the rule could not stand as written.

The vacatur matters beyond a single chemical. Methylene chloride was one of the first substances to move through EPA's full TSCA Section 6 risk-management pipeline after the Lautenberg amendments, alongside trichloroethylene and other solvents flagged in the agency's first ten chemical risk evaluations. The Fifth Circuit's reasoning will be parsed by lawyers for both industry and public-health groups for signals about how much deference courts will give EPA's worker-exposure determinations and its choice of regulatory controls under Section 6(a).

EPA now faces a decision point. The agency can seek rehearing or Supreme Court review, or it can begin a new rulemaking that cures the legal defects the court identified. Each path carries a different timeline, and until one resolves, the regulatory status of methylene chloride restrictions is in limbo. Companies that had built compliance programs — exposure monitoring, workplace chemical protection plans, phase-out schedules — around the rule must now assess whether those obligations remain enforceable and what state-level regimes, such as California's Proposition 65 listings and state occupational standards, fill any gap.

The decision also adds uncertainty to EPA's queue of pending Section 6 rules. The agency has been working through risk-management actions for the remainder of its first-ten chemicals and the initial tranche of high-priority substances under the cyclic risk-evaluation program. A vacatur on foundational legal questions invites similar challenges to rules for other solvents and to the framework itself.

What happens next turns on procedural milestones: whether EPA petitions for en banc rehearing at the Fifth Circuit or files a certiorari petition, and how quickly the agency signals whether it will reissue the methylene chloride rule. Those filings will determine whether the workplace restrictions return in revised form — or whether chemical users operate without federal methylene chloride limits for the foreseeable future.