Dichloromethane

Dichloromethane, also known as methylene chloride or DCM (CAS # 75-09-2) is a colorless liquid with a mild, sweet, chloroform-like odor.  It is often used as an industrial solvent, for metal cleaning and degreasing, in pharmaceutical manufacturing, and in various paint strippers. Researchers use methylene chloride for various processes, including chromatography, chemical synthesis, and chemical separations.

 

Dichloromethane is regulated by both the U.S. Environmental Protection Agency (EPA) under Section 6(a) of the Toxic Substances Control Act (TSCA) and the Occupational Safety and Health Administration (OSHA) under 29 CFR 1910.1052, Methylene Chloride. OSHA classifies DCM as a hazardous substance and regulates occupational exposure through requirements for exposure monitoring, engineering controls, respiratory protection, medical surveillance, training, and other protective measures.

 

In April 2024, EPA finalized a risk-management rule under TSCA Section 6 that prohibits the manufacture, processing, and distribution of DCM for consumer uses and most industrial and commercial uses. The rule also prohibits many specific uses of DCM but allows certain uses, including laboratory use, to continue subject to additional workplace protections under EPA's Workplace Chemical Protection Program (WCPP) which provide stricter regulatory requirements and exposure limits than those outlined by OSHA. Montana State University is allowing the continued use of DCM in research laboratories that meet both OSHA and EPA regulatory requirements.

Montana State University encourages researchers to evaluate safer alternatives to DCM. There are many online resources available for determining an appropriate substitute, including those published by the American Chemical Society and Green Chemistry. Safety review for use of DCM at Montana State University will require justification that a safer alternative is not available. 

In addition to Montana State University's institutional Workplace Chemical Protection Program (WCPP), any lab intending to use DCM must fill out a laboratory specific Exposure Control Plan and a detailed Standard Operating Procedure for any unique process in which they will use DCM. These documents must be submitted to Safety and Risk Management Chemical Safety Officers at jessicalustybeech@montana.edu and cody.ragan1@montana.edu. Following review, SOPs will either be returned for modification or approved for exposure monitoring. Safety and Risk Management will coordinate with Principal Investigators for exposure monitoring and advise next steps based on exposure results as outlined in the WCPP.