EPA Releases Draft Revised Risk Determination for Methylene Chloride for Public Comment

Released on July 5, 2022.

Today, the U.S. Environmental Protection Agency (EPA) released for public comment a draft revision to the unreasonable risk determination for methylene chloride pursuant to the Toxic Substances Control Act (TSCA) section 6(b). The draft revised risk determination proposes to find that methylene chloride, as a whole chemical substance, presents an unreasonable risk of injury to human health under the conditions of use.

The methylene chloride draft revised risk determination incorporates policy changes announced in June 2021 to ensure the public is protected from unreasonable risks from chemicals in a way that is supported by science and the law. EPA’s proposed revisions will ensure that, when finalized, the methylene chloride risk determination better aligns with the objectives of protecting health and the environment under the amended TSCA.

Methylene chloride is a volatile chemical used as a solvent in vapor degreasing, metal cleaning, in the production of refrigerant chemicals, and as an ingredient in sealants and adhesive removers. Common consumer uses include adhesives, sealants, degreasers, cleaners and automobile products.

EPA’s methylene chloride risk evaluation identified adverse human health effects, including neurotoxicity and liver effects, from acute and chronic inhalation and dermal exposures to methylene chloride. EPA also identified cancer as one adverse human health effect of chronic inhalation and dermal exposures to methylene chloride.

The draft revised risk determination for methylene chloride does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE). This decision should not be viewed as an indication that EPA believes there is widespread non-compliance with applicable OSHA standards. In fact, EPA has received public comments from industry respondents about occupational safety practices currently in use at their facilities. EPA will consider these comments, as well as other information on use of PPE and other ways industry protects its workers, as potential ways to address unreasonable risk during the risk management process.

Not assuming use of PPE in its baseline exposure scenarios reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed because they are not covered by Occupational Safety and Health Administration (OSHA) standards, because their employers are out of compliance with OSHA standards, because OSHA’s chemical-specific Permissible Exposure Limits (largely adopted in the 1970’s) are described by OSHA as being “outdated and inadequate for ensuring protection of worker health,” or because the OSHA permissible exposure limit alone may be inadequate for ensuring protection of worker health, as is the case for methylene chloride.  

As EPA moves forward with risk management rules for methylene chloride, the agency will strive for consistency with existing OSHA requirements or best industry practices when they are sufficiently protective. EPA will propose occupational safety measures in the risk management process that meet TSCA’s statutory requirement to eliminate unreasonable risk of injury to health and the environment.

Overall, 52 of the 53 conditions of use EPA evaluated would drive the methylene chloride whole chemical unreasonable risk determination due to risks identified for human health. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for methylene chloride would mean that five additional conditions of use in addition to the original 47 would drive the unreasonable risk determination for methylene chloride. Additional inhalation risks would drive the unreasonable risk in three conditions of use and additional risk to workers for acute and chronic non-cancer dermal exposures and for cancer from inhalation exposures would also drive the unreasonable risk in many of those 52 conditions of use. One out of 53 conditions of use would not drive the unreasonable risk: distribution in commerce.

Separately, EPA is conducting a screening approach to assess potential risks from the air and water pathways for several of the first 10 chemicals, including methylene chloride. For methylene chloride the exposure pathways that were or could be regulated under another EPA administered statute were excluded from the 2020 risk evaluation. This resulted in the surface water, drinking water, ambient air, and sediment pathways for methylene chloride not being assessed for human health exposures or the general population. EPA’s screening approach will identify if there are risks that were unaccounted for in the risk evaluation for methylene chloride. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for methylene chloride will protect against these risks or if the risk evaluation will need to be formally supplemented or revised.

Note that EPA has not conducted new scientific analysis on methylene chloride as part of today’s actions. The methylene chloride risk evaluation continues to characterize risks associated with individual conditions of use. EPA will continue to rely on the evaluation of each condition of use to support any determination of unreasonable risk for methylene chloride as a whole chemical substance.

EPA will accept public comments on the draft revised risk determination for 30 days following publication in the Federal Register via docket EPA-HQ-OPPT-2016-0742 at www.regulations.gov.

Read the Draft Revised Unreasonable Risk Determination for Methylene Chloride.