April 27, 2023

EPA Proposes Ban on Most Uses of Methylene Chloride

On April 20, EPA announced a proposed rule that would ban most uses of methylene chloride, a chemical used as a solvent in vapor degreasing and metal cleaning as well as an ingredient in sealants and adhesive removers. Methylene chloride also has consumer applications in adhesives, sealants, degreasers, cleaners, and automobile products. Following last year’s proposed actions to ban chrysotile asbestos, the new EPA proposal regarding methylene chloride is the second to be issued through a new process that calls for the agency to evaluate and address the safety of existing chemicals regulated under the Toxic Substances Control Act, as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act in 2016. The pre-publication copy of EPA’s proposed rule (PDF) explains that methylene chloride “is acutely lethal, a neurotoxicant, a likely human carcinogen, and presents cancer and non-cancer risks following chronic exposures as well as acute risks.”

In addition to prohibiting the manufacture, processing, and distribution of methylene chloride for all consumer uses, EPA’s proposal would ban most of the chemical’s industrial and commercial uses. Manufacturers, importers, processors, and distributors would be required to notify companies that receive methylene chloride shipments about these prohibitions and to keep records. However, the proposed rule would allow some military, industrial manufacturing, and industrial processing uses of methylene chloride under what EPA describes as “a workplace chemical protection program with strict exposure limits to better protect workers.” Examples of uses EPA’s proposal would allow to continue include the processing of methylene chloride to produce chemicals related to efforts to reduce global warming as well as specific uses required by the National Aeronautics and Space Administration, the Department of Defense, and the Federal Aviation Administration.

According to EPA’s press release, the agency consulted with OSHA and considered existing OSHA requirements while developing the proposed worker protections outlined in the rule. The pre-publication copy of the proposal explains that the workplace chemical protection program mentioned above would include requirements related to inhalation exposure concentration limits and exposure monitoring for certain continued conditions of use of methylene chloride. The program would also include an existing chemical exposure limit (ECEL) that EPA describes as “an 8-hour occupational inhalation exposure limit based on the point of departure of the endpoint that drives the unreasonable risk determination,” which in the case of methylene chloride is chronic non-cancer liver effects. EPA’s proposed ECEL for methylene chloride is 2 ppm as an 8-hour time-weighted average, and its proposed short-term exposure limit is 16 ppm as a 15-minute TWA. These limits are lower than OSHA’s permissible exposure limit for methylene chloride of 25 ppm as an 8-hour TWA and STEL of 125 ppm.

EPA plans to host a webinar on this topic for employers and workers in the coming weeks. The agency will also open a 60-day public comment period on the proposed rule for methylene chloride following its publication in the Federal Register.

For more information, see EPA’s webpage on risk management for methylene chloride.

Related: A revised risk determination finalized by EPA in November 2022 found that methylene chloride “presents an unreasonable risk of injury to human health.” Adverse human health effects from acute and chronic inhalation and dermal exposures to methylene chloride include neurotoxicity and liver effects, EPA noted. The agency also identified risks for cancer from chronic inhalation and dermal exposures to the chemical.