METHYLENE CHLORIDE

What is methylene chloride (dichloromethane)?

Methylene chloride (CAS # 75-09-2), also known as dichloromethane, is a colorless liquid with a mild, sweet odor that can be detected as low as 0.9 parts per million (odor threshold). Methylene chloride is a volatile solvent, a neurotoxicant, and a carcinogen, used in laboratories, workshops, and facilities that is commonly found as a stock chemical or as a component in degreasing products, paint strippers, metal cleaners, and aerosols.

What is changing?

On May 8, 2024, the United States Environmental Protection Agency (USEPA) issued a final rule regulating the manufacture, distribution, and use of methylene chloride (89 FR 39254). This rule was issued under the authority of the Toxic Control Substance Control Act. The rule bans certain uses of methylene chloride and restricts certain other uses. This rule has the potential to impact the Stony Brook University community, particularly laboratories who use methylene chloride as a laboratory solvent/reagent, and facilities and services using certain products containing methylene chloride such as paint strippers, adhesives, sealants, and degreasers/cleaners. The changes under this final rule are not limited to just laboratories and facilities - they affect any and all locations that utilize methylene chloride-containing materials. While discontinuing use of methylene chloride would be the best possible solution, it may not be feasible for all areas.

The rule contains prohibitions to the types of activities that can be performed with
methylene chloride, prohibitions of the manufacture, processing, and distribution of
methylene chloride for all consumer use.

The rule also requires a Workplace Chemical Protection Program (WCPP) to be
developed and implemented. This WCPP contains varying dates of compliance, with
regulated entities being required to begin conducting exposure assessments in certain
circumstances no later than May 2025.

If you have methylene chloride in your work area, regardless of if you choose to
continue working with it in the future, you must complete this form. EHS will follow-up on
all submissions to assess each use individually and collaborate with the campus
community to develop compliance plans.
The safest method to reducing exposure to methylene chloride is to eliminate its use in the laboratory where feasible. This can include disposing of legacy materials.
Substitution with safer alternatives may be feasible in select cases depending on the process(es) involved.
- Fisher Scientific – Green Chemistry Chemical Replacement Cross Reference
- University of Pennsylvania – Fact Sheet: Solvent Alternatives
- Link
When elimination or substitution are not viable options, carefully review your process(es) to determine if scaling down is an option to reduce the volume used as well as the volume kept in storage. Additional information will be provided as the scope of methylene chloride use in
campus laboratories is better defined. Make sure to complete the form if your laboratory uses methylene chloride.
Provisions of this final rule limit the types of work that can be performed with materials containing methylene chloride. It also sets new inhalation exposure limits and requires related workplace exposure monitoring and exposure controls for work that is still permitted. In order for EH&S to better understand your use of methylene chloride- containing materials, you are required to complete this form regarding your (or your vendors’) use of these materials.

The provisions of the final rule for methylene chloride include prohibitions on the manufacture and distribution for all consumer use. This may affect your ability to purchase methylene chloride-containing solvents and sprays in the immediate future.

This may also affect contractors and vendors depending on the types of work they perform under contract and the materials they use to complete that work. This section will be updated regularly as more information becomes available.