Skip to main content
Environmental Health and Safety

Methylene Chloride

The Environmental Protection Agency (EPA) has evaluated methylene chloride under section 6(b) of the Toxic Substances Control Act and found that methylene chloride presents unreasonable risk of injury to health of potentially exposed persons and issued the Methylene Chloride; Regulation under Section 6(a) of the Toxic Substances Control Act (also known as the methylene chloride rule) that went into effect July 8, 2024.

Under this rule, the EPA allows limited and controlled continued use for research purposes with additional work protections. Environmental Health and Safety (EHS) will be helping researchers adapt to this new ruling in the following ways:

  • Performing initial exposure monitoring to determine exposure levels and notification of additional required work protections.
  • Periodic monitoring to ensure levels remain below allowable concentrations.
  • Assistance in removing methylene chloride from laboratory spaces through EHS Hazardous Waste Pick-Up Requests.
  • Assistance with identifying solvent alternatives.

Methylene Chloride Health Risks

Methylene chloride poses significant health risks. It is readily absorbed by both inhalation and through the skin, including toxicity to the central nervous system and possible carcinogenicity. Methylene chloride metabolizes in the body to form a chemical asphyxiant, carbon monoxide. The new EPA exposure limits are an order of magnitude lower than the previous limits set by OSHA. Click here to learn more about the public health risks.

ISU Lab Guidelines for Working with DCM

Laboratories that choose to continue using methylene chloride will be required to take additional steps. Workers must undergo initial exposure monitoring and complete specific training on the use and handling of methylene chloride. Additionally, the lab must be familiar with the Workplace Chemical Protection Program (WCPP) and create an Exposure Control Plan(s) (ECP) for each experiment and procedure involving methylene chloride.

  1. If you utilize methylene chloride, also known as dichloromethane, or DCM, within your laboratory, please ensure that it is listed in your chemical list.
  2. If you currently have DCM in your laboratory but do NOT use it, please submit an EHS hazardous waste pick-up request and remove it from your chemical list.
  3. If you are NOT using DCM for research purposes, (e.g., paint or paint stripper in arts), please submit an EHS hazardous waste pick-up request to remove DCM and any substituents containing DCM. Non-research use of DCM is not allowed under the new ruling.
  4. Laboratories that store, use, or plan to use methylene chloride will be contacted by EHS to coordinate further actions for compliance. At minimum each lab is responsible for the following:
    1. Exposure Monitoring-
      1. Must be conducted every 5 years for all labs using or storing DCM.
      2. Must be conducted quarterly or annually for laboratories that approach or exceed EPA exposure limits.
    2. Regulated Areas – if exposure limits are reasonably expected to be exceeded.
    3. Exposure Control Plan – must describe consideration or implementation of the following:
      1. Elimination of DCM
      2. Substitution of DCM
      3. Engineering Controls
      4. Administrative Controls
      5. Personal Protective Equipment
    4. Training Prior to Job Assignment
    5. Recordkeeping

Policies and Training

  • Workplace Chemical Protection Program (WCPP)

ISU Workplace Chemical Protection Program

  • Exposure Control Plan (ECP)

ISU Exposure Control Plan

Fact Sheets

Other Resources