Methylene Chloride (Dichloromethane)
Use of Methylene Chloride - Evaluation and Approval Process
To initiate the evaluation and approval process, complete the Methylene Chloride Exposure Control Plan and submit the completed form to labsafety@MiamiOH.edu. A representative from the Office of Research and Innovation will contact you to review the information provided in the form and initiate the required personal air sampling by the Environmental Health and Safety Office.
Hazards
According to the Occupational Safety and Health Administration (OSHA), “employees exposed to methylene chloride are at increased risk of developing cancer, adverse effects on the heart, central nervous system and liver, and skin or eye irritation. Exposure may occur through inhalation, by absorption through the skin, or through contact with the skin.”
The Safety Data Sheet (SDS) for methylene chloride includes the following hazard statements:
- Causes skin irritation
- Causes serious eye irritation
- May cause drowsiness or dizziness
- May cause cancer
- May cause damage to organs through prolonged or repeated exposure
Hierarchy of Controls
Elimination and Substitution
Whenever feasible, experimentation requiring the use of methylene chloride should be redesigned to eliminate its use. A determination regarding possible substitutions of methylene chloride in the experimentation must be evaluated. Several resources are available to assist in the selection of an alternative material in the “References” section at the end of this document.
Administrative Controls
- Minimize the amount of methylene chloride that is used in the experimentation and the amount that is stored within the laboratory space.
- Reduce the amount of time each researcher spends performing tasks utilizing methylene chloride.
- Ensure all researchers have completed the training assigned by the Office of Research and Innovation and have undergone the lab-specific training provided by the Principal Investigator.
- Ensure all researchers review the Miami University Hazard Communication Program and adhere to the requirements outlined in the program.
- Prevent the accumulation of methylene chloride waste by routinely scheduling hazardous waste disposal with the Environmental Health and Safety Office.
- Ensure that all researchers inspect and appropriately don and doff their PPE.
- Prohibit the entry of unauthorized personnel into the laboratory space.
Engineering Controls
Methylene chloride must be used within a chemical fume hood. In approved experimentation, there may be instances where methylene chloride is used in another containment device and vented through the chemical fume hood.
Personal Protective Equipment and Laboratory Attire
General Attire
All laboratory occupants must adhere to the following guidelines regarding appropriate laboratory attire:
- Pants: Full-length pants or long skirts are required. No shorts or short skirts. The pants must not have any rips or tears that would result in exposed skin.
- Shirts: No tank tops, crop tops, open-shoulder shirts, or shirts designed with openings present on the sleeves or back are permitted.
- Shoes: Closed-toe shoes are required. No sandals, slides, open-heel shoes, or shoes exposing the top of the foot.
Skin Protection
A laboratory coat must be worn by laboratory personnel using methylene chloride. The use of polyethylene/ethylene vinyl alcohol or polyethylene gloves is required. Nitrile gloves are recommended as a second layer on top of the polyethylene/ethylene vinyl alcohol or polyethylene gloves. Nitrile gloves alone are not a sufficient barrier to protect researchers from exposure to methylene chloride. For additional assistance selecting the appropriate PPE, please contact the Office of Research and Innovation at labsafety@MiamiOH.edu.
Eye Protection
The use of splash-resistant laboratory goggles is required for all uses of methylene chloride. The use of safety glasses in lieu of goggles is prohibited. All researchers must inspect their goggles for any damage or defects prior to use. If damage or defects are present, the goggles must be immediately disposed of, and a new pair of goggles must be worn.
Exposure Limits
The Occupational Health and Safety Administration (OSHA) previously regulated the exposure limits of methylene chloride in 29 CFR 1910.1052. On July 8, 2024, the U.S. Environmental Protection Agency (EPA) introduced a new rule drastically reducing the exposure limits for methylene chloride. The table below provides a comparison of the previous values enforced by OSHA versus the new values from the EPA.
| OSHA | 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 |
Storage Requirements
Methylene chloride must be stored in a dry, cool, and well-ventilated area away from ignition sources. Methylene chloride must not be stored with strong oxidizing agents, strong acids, or amines. Review the Safety Data Sheet from the manufacturer prior to purchase and use. Visit the Environmental Health and Safety Office website for access to Chemwatch.
Hazardous Waste
All hazardous waste generated during experimentation must be disposed of in accordance with the Waste Management Guide. Please visit the Environmental Health and Safety Office website for additional information.
Training
Prior to initiating procedures utilizing methylene chloride, the Principal Investigator and all researchers using methylene chloride or working in a lab or studio space containing methylene chloride must complete “Fundamentals of Methylene Chloride Safety” offered by the U.S. Centers for Disease Control and Prevention (CDC). In addition, the Principal Investigators and all researchers must complete the training outlined in the Miami University Hazard Communication Program. All certificates of completion must be submitted to labsafety@MiamiOH.edu.
Purchasing Restrictions
Requisitions attempting to purchase methylene chloride are required to use Spend Category SC0598 “Controlled Solvent Purchases.” Any laboratory with the intent to use methylene chloride must pass the exposure testing process before being approved to use or purchase methylene chloride. If you have any questions, please contact the Office of Research and Innovation at labsafety@MiamiOH.edu.
Resources
Regulatory Information and Safety Information:
Miami University. Emergency Procedures and Contacts - Chemical Spill.
Occupational Safety and Health Administration. 29 CFR 1910.1052 - Methylene Chloride.
Occupational Safety and Health Administration. Methylene Chloride - Hazard Recognition.
Occupational Health and Safety Administration: Methylene Chloride - Overview.
ThermoFisher Scientific. Safety Data Sheet: Methylene Chloride.
United States Environmental Protection Agency. Risk Management for Methylene Chloride.
Alternative Solvent Selection Resources:
American Chemical Society. DCM Ban: Alternatives & Resources for Dichloromethane.
Green Chemistry Teaching and Learning Community. Methylene Chloride (DCM) Replacements.
Questions
If you have any questions related to the use of methylene chloride in your lab space, please contact the Office of Research and Innovation at labsafety@MiamiOH.edu.