The U. S. Environmental Protection Agency (EPA) published a new rule for methylene chloride (also known as dichloromethane) for worker safety and public and environmental protection. The required actions and timelines to comply with the new rule are described below. The new EPA rule is in addition to existing Washington State Department of Labor & Industries rules for workplace safety.
Environmental Health & Safety (EH&S) is asking University units and departments that use or possess methylene chloride to start taking steps (described below) to prepare for the new rule.
- University units check their workspaces for methylene chloride, ensure all items are inventoried in MyChem, determine whether their use is allowed under the new rules, and find replacements.
- January-May 2025: EH&S conducts exposure monitoring for locations where methylene chloride is allowed and where it cannot be replaced or eliminated.
- Before October 30, 2025: Units allowed to use methylene chloride under the new rule are required to implement an exposure control plan. (EH&S will provide a template.)
- After April 28, 2026: The University will be prohibited from industrial or commercial use of methylene chloride, including any methylene chloride-containing products (except for allowed uses).
Actions
University units and departments that use or possess methylene chloride are required to do the following:
1. Check your workspace for methylene chloride; ensure all items are inventoried in MyChem. If your inventory contains methylene chloride or methylene chloride-containing solutions (≥0.1% by weight), continue to #2.
2. Review the EPA’s Fact Sheet to determine if your use of methylene chloride is allowed or prohibited under the new rules.
3. Eliminate methylene chloride or substitute it for a less hazardous chemical where possible.
- Elimination or substitution is required for prohibited uses and strongly recommended for allowed uses.
- Find a replacement for prohibited uses by December 31, 2024.
4. Promptly remove chemicals that are no longer in use.
- Label containers as hazardous waste.
- Request chemical waste collection.
Replacements for methylene chloride
Laboratories
University laboratories can use the following resources to find replacements for products containing methylene chloride.
- The American Chemical Society (ACS) Green Chemistry Institute has developed a Solvent Tool, and the Organic Photonics & Electronics Group at Umeå University has similarly developed a Green Solvent Selection Tool, which can be used to help select solvents based on a variety of physical and chemical properties.
- The Green Chemistry Teaching and Learning Community has published a resource library page with a variety of other tools for elimination/substitution.
Please note: Other chemicals will be undergoing EPA rulemaking and may face similar restrictions as methylene chloride in the future including: N-Methylpyrrolidone (NMP), 1-Bromopropane (1-BP), 1,1,2-Trichloroethane (TCE), Perchloroethylene (PCE).
Facilities, shops and other non-laboratory locations
University facilities and shops can use the following resources to find replacements for products containing methylene chloride.
- The EPA has evaluated a list of alternative products (Appendix A and B), which can be used to help find replacement products based on condition of use.
- N-Methylpyrrolidone (NMP), 1-Bromopropane (1-BP), 1,1,2-Trichloroethane (TCE), Perchloroethylene (PCE) are undergoing rulemaking and may face similar restrictions as methylene chloride in the future. The EPA Appendix B: Alternatives Calculator for Solvents can be filtered to specifically exclude these chemicals.
After April 28, 2026: All persons are prohibited from industrial or commercial use of methylene chloride, including any methylene chloride-containing products (except for allowed uses).
Usage requirements
If it is not possible to eliminate or substitute methylene chloride and your use is allowed, the following usage requirements will apply:
- By May 5, 2025: EH&S will complete workplace exposure monitoring where required.
- Before October 30, 2025: You will be required to implement a written methylene chloride standard operating procedure (SOP) to meet the EPA’s exposure control plan requirement.
- EH&S is updating the Methylene Chloride SOP Template to incorporate the required elements of the EPA’s exposure control plan. We expect the updated Methylene Chloride SOP Template to be available by spring quarter 2025.
- Implement safety measures (such as the use of chemical fume hoods) to contain vapors and personal protective equipment (such as lab coats and gloves) to help prevent workplace exposure.
About the new rule
In April 2024, EPA finalized prohibitions and workplace protections under the Toxic Substances Control Act (TSCA) for methylene chloride to protect human health. The rule requires more stringent workplace safety protections.
Many uses of methylene chloride such as paint stripping, degreasing, and adhesive removing will be prohibited under the new rules. Specific uses of methylene chloride will be allowed with more stringent worker protections including an exposure control plan and exposure monitoring to protect workers from associated health risks from elevated exposure. Adverse health effects from exposure to methylene chloride include neurotoxicity (i.e., damage to the brain or nervous system caused by exposure to a toxic substance) and cancer of the lungs and liver.
The new rule is in addition to Washington state methylene chloride workplace safety standard (WAC 296-62-0747).
More information about the EPA’s risk evaluation of methylene chloride can be found on the EPA's website.
Please contact Environmental Health & Safety with questions.
This article was first published on October 8, 2024.