Methylene chloride (dichloromethane or DCM) is a widely used solvent in consumer, commercial, and academic settings. The EPA has deemed it an “unreasonable risk to human health or the environment” under TSCA regulations. As of April 2024, most consumer and commercial uses are prohibited, except for laboratory use, which requires a workplace chemical protection program (WCPP).
Methylene chloride presents both non-cancer and cancer health risks through acute and chronic inhalation and skin contact. University staff exposed to it may face increased cancer risk, as suggested by some animal studies. Other potential health effects include neurotoxicity (headaches, dizziness), heart and liver damage, and skin or eye irritation.
The new EPA regulation has significantly lowered the exposure threshold for methylene chloride compared to the OSHA standard (See Table 1). For context, the odor threshold is 250 parts per million (ppm), which is 125 times higher than the new eight-hour time weighted average (TWA) of 2 ppm.
| Rule |
OSHA |
New EPA |
|---|---|---|
| 8-Hour Time Weighted average (TWA) |
25 ppm |
2 ppm |
| 15-Minute Short Term Exposure Limit (STEL) |
125 ppm |
16 ppm |
| Action Level |
12.5 ppm |
1 ppm |
Includes Compliance Guidance on Prohibitions, Workplace Chemical Protection Program (WCPP), and Other Requirements
EPA Printable Fact Sheet about the Regulation of Methylene Chloride under the TSCA
Information on EPA actions to manage the unreasonable risk from methylene chloride and protect public health. Methylene chloride, also known as dichloromethane and DCM, is a volatile chemical used in a wide range of industrial, commercial, and consumer applications like adhesives, sealants, degreasers, cleaners, and automobile products.
Laboratories engaged in research must consider the applicability of the Toxic Substances Control Act (TSCA) on their operation. The Toxic Substances Control Act (TSCA), administered by the U.S. Environmental Protection Agency (EPA), is intended to ensure that the human health and environmental effects of chemical substances are identified and adequately addressed prior to production or transport of those substances. Activities regulated under TSCA can include:
Each laboratory or research group must determine if TSCA applies to their laboratory activities. The TSCA informational resources and tools listed are designed to assist you in this process. Laboratory Directors, PIs, and laboratory managers/supervisors should familiarize themselves with TSCA by referring to the TSCA Fact Sheet and TSCA Roles and Responsibilities.
The Toxic Substance Control Act also requires laboratory research personnel to forward any allegations of significant adverse environmental or health reactions to chemicals substances handled in the laboratory and report data generated as part of your research that suggests a chemical substance may present a significant risk to human health or the environment.
If you are involved in commercial activities, work at the pilot plant scale, or are using chemical substances in activities other than teaching, clinical or research laboratories, provisions other than those described on this site may apply. Contact EHS TSCA Coordinator for assistance in assessing your obligations under the EPA’s Toxic Substance Control Act.
