Methylene chloride, also called dichloromethane, is a volatile, colorless liquid with a chloroform-like odor. Methylene chloride is used in various industrial processes, in many different industries including paint stripping, pharmaceutical manufacturing, paint remover manufacturing, and metal cleaning and degreasing. The most common means of exposure to methylene chloride is inhalation and skin exposure. OSHA considers methylene chloride to be a potential occupational carcinogen.

OSHA Standards

Exposures to methylene chloride are addressed in specific standards for general industry, shipyard employment and the construction industry. This section highlights OSHA standards, preambles to final rules (background to final rules), Federal Registers (rules, proposed rules, and notices), directives (instructions for compliance officers), and standard interpretations (official letters of interpretation of the standards) related to methylene chloride. Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.

General Industry (29 CFR 1910)

• 1910 Subpart Z, Toxic and hazardous substances [related topic page]
  • 1910.1052, Methylene chloride
    • Appendix A, Substance safety data sheet and technical guidelines for methylene chloride
    • Appendix B, Medical surveillance for methylene chloride
    • Appendix C, Questions and answers – methylene chloride control in furniture stripping

Shipyard Employment (29 CFR 1915)

• 1915 Subpart Z, Toxic and hazardous substances
  • 1915.1052, Methylene chloride

Construction Industry (29 CFR 1926)

• 1926 Subpart Z, Toxic and hazardous substances
  • 1926.1152, Methylene chloride

Preambles to Final Rules

• Methylene Chloride (1997)
  


• Search all available preambles to final rules.

Federal Registers

• Notice of Availability of the Regulatory Flexibility Act Review of the Methylene Chloride Standard. Proposed Rules 75:24509-24510, (2010, May 5).
  


• Regulatory Flexibility Act Review of the Methylene Chloride Standard. Proposed Rules 72:37501-37503, (2007, July 10).
  


• Methylene Chloride; Final Rule. Final Rules 63:50711-50732, (1998, September 22). OSHA amended its standard regulating occupational exposure to methylene chloride (29 CFR 1910.1052) by adding a provision for temporary medical removal protection benefits for employees who are removed or transferred to another job because of a medical determination that exposure to methylene chloride may aggravate or contribute to the employee's existing skin, heart, liver, or neurological disease.
  


• Search all available Federal Registers.

Directives

• Inspection Procedures for Occupational Exposure to Methylene Chloride Final Rule 29 CFR Part 1910.1052, 29 CFR Part 1915.1052 and 29 CFR Part 1926.1152. CPL 02-02-070 [CPL 2-2.70], (2001, December 14). Ensures uniform enforcement of the Occupational Exposure to Methylene Chloride Standard as amended in the Federal Register (September 22, 1998), by setting enforcement policy, providing inspection guidelines, and clarifying and interpreting the regulatory text.
  


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Standard Interpretations

• Determination of airborne concentrations of methylene chloride; protection of employees covered by 1910.1052. (2003, May 12).
  


• Amendments to methylene chloride standard. (1998, November 20). Discusses the changes made to the methylene chloride standard.
  


• Partial stay of methylene chloride standard. (1998, February 6). Discusses concerns regarding whether methylene chloride used as a solvent or bonding agent is covered by the "formulation of products" stay for the methylene chloride standard.
  


• Petition for modification of OSHA's methylene chloride standard. (1997, July 7). Response to a petition to modify medical surveillance requirements, which was denied.
  


• OSHA's methylene chloride standard. (1997, July 3). Provides information on the feasibility of implementing the standard without replacing methylene chloride with another substance.
  


• OSHA's methylene chloride standard. (1997, June 5). Clarifies some of the misimpressions being raised about the risks of methylene chloride exposure and the methods available to reduce those risks to the US workforce.
  


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Hazard Recognition

Methylene chloride is a solvent which is used in many different types of work activities, such as paint stripping, polyurethane foam manufacturing, cleaning, and degreasing. 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 following references aid in recognizing methylene chloride hazards in the workplace.

• Methylene Chloride. National Institute for Occupational Safety and Health (NIOSH), (1994, May). Provides an Immediately Dangerous to Life or Health (IDLH) document that includes acute toxicity data for methylene chloride.
  
  
• Methylene Chloride. National Institute for Occupational Safety and Health (NIOSH), Current Intelligence Bulletin No. 46, (1986, April 18). Describes a study where mice that were exposed to methylene chloride in air, developed cancers (alveolar/bronchiolar carcinomas) and tumors (alveolar/bronchiolar adenomas) of the lung, and cancers (hepatocellular carcinomas) of the liver.
  
  
• Criteria for a Recommended Standard: Occupational Exposure to Methylene Chloride. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication 76-138, (1976, March). Includes biological effects, exposure, and work practice information for methylene chloride.
  
  
• TOXNET for Dichloromethane. The National Library of Medicine Hazardous Substance Database.
  
  
• Report on Carcinogens (RoC). US Department of Health and Human Services (DHHS), National Toxicology Program (NTP). Identifies and discusses agents, substances, mixtures, or exposure circumstances that may pose a health hazard due to their carcinogenicity. The listing of substances in the RoC only indicates a potential hazard and does not establish the exposure conditions that would pose cancer risks to individuals.
  • Dichloromethane [139 KB PDF, 3 pages]. NTP classification: Reasonably anticipated to be a human carcinogen
• International Agency for Research on Cancer (IARC) Monographs on the Evaluation of Carcinogenic Risks for Humans [225 KB PDF, 66 pages]. World Health Organization, International Agency for Research on Cancer. IARC Classification: Possibly carcinogenic to humans (Group 2B).
  
  
• Toxicological Profile for Methylene Chloride. Agency for Toxic Substances and Disease Registry (ATSDR), (2000, September). Provides exposure risks, exposure limits, and health effects for methylene chloride.
  
  
• ToxFAQs for Methylene Chloride. Agency for Toxic Substances and Disease Registry (ATSDR), (2001, February). Summarizes the properties and health effects for methylene chloride.
  
  
• Dichloromethane (CASRN 75-09-2). Environmental Protection Agency (EPA), Integrated Risk Information System (IRIS). Discusses the health effects of dichloromethane.
  
  
• Methylene Chloride (Dichloromethane). Environmental Protection Agency. Lists methylene chloride as a Hazardous Air Pollutant (HAP) under the National Emissions Standard Hazardous Air Pollutants section of its Clean Air Act.
  
  
• Methylene Chloride [620 KB PDF, 6 pages]. New Jersey Department of Health and Senior Services, Hazardous Substance Fact Sheet, (2001, May). Provides a summary source of information of all potential and most severe health hazards that may result from methylene chloride exposure.
  


• International Chemical Safety Cards: Dichloromethane. National Institute for Occupational Safety and Health (NIOSH), (2000). Summarizes essential health and safety information on methylene chloride.
  

Exposure Evaluation

Monitoring employee exposures to methylene chloride enables employers to identify the sources of methylene chloride and select appropriate exposure controls. OSHA's methylene chloride standard requires that all facilities using methylene chloride monitor employee exposures. The following references aid in evaluating methylene chloride exposures in the workplace.

• Methylene Chloride. OSHA Publication 3144-06R, (2003). Also available as a [ PDF^*- 556 KB, 26 pages]. Provides general information regarding methylene chloride exposure limit information, control measures, and other OSHA assistance information.
  


• Methylene Chloride Facts No. 1 - Exposure Monitoring Requirements. OSHA, (1998). Provides only general information on monitoring requirements and should not be considered to be a complete summary of the methylene chloride related monitoring requirements.
  
  
• Chemical Sampling Information. OSHA, (1999, January 14). Presents, in concise form, data on a large number of chemical substances that may be encountered in industrial hygiene investigations. Basic reference for industrial hygienists engaged in OSHA field activity.
  • Methylene Chloride
• OSHA Occupational Chemical Database. OSHA maintains this chemical database as a convenient reference for the occupational safety and health community. It compiles information from several government agencies and organizations. This database originally was developed by OSHA in cooperation with EPA.
  • Methylene Chloride
    

Analytical Methods

OSHA

OSHA has developed and validated methods for use by the Salt Lake Technical Center (SLTC) laboratory. The following method has been adopted by many laboratories for the analysis of chemical compounds. Exposures should be evaluated with standard total dust sampling techniques for comparison to the OSHA permissible exposure limits (PEL).

• Methylene Chloride. Fully Validated Method 59, (1986, April).
  
  
• Methylene Chloride. Fully Validated Method 80, (1990, February).
  

Possible Solutions

Controlling the exposure to methylene chloride may be done through engineering controls, administrative actions, and personal protective equipment. Engineering controls include isolating the source and using ventilation systems. Administrative actions include limiting the worker's exposure time and washing facilities. Personal protective equipment includes wearing the proper respiratory protection and clothing. The following resources contain information to help control exposures.

• Methylene Chloride Small Entity Compliance Guide Fact Sheets. OSHA, (1998). Discusses monitoring requirements, suggested engineering and work practice controls, substitutes, respirator use, protective equipment, and compliance schedules for various small businesses.  A collection of 11 documents that provide suggestions for controls and work practices in nine industries and operations.
  
  
• NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational Safety and Health (NIOSH) Publication No. 2005-149, (2007, September). Provides a physical description, exposure limits, measurement method, personal protection and sanitation, first aid, respirator recommendations, exposure routes, symptoms, target organs, and cancer sites.
  • Methylene chloride
• Occupational Health Guidelines for Chemical Hazards. National Institute for Occupational Safety and Health (NIOSH), (1981, January). Contains information on identification, physical and chemical properties, health hazards, exposure limits, exposure sources and control methods, monitoring, personal hygiene, storage, spills and leaks, and personal protective equipment.
  
  
• Questions and Answers - Methylene Chloride Control in Furniture Stripping. National Institute for Occupational Safety and Health (NIOSH) Publication No. 93-133, (1997, September). Answers commonly asked questions about the hazards from exposure to methylene chloride. Also describes approaches to controlling methylene chloride exposure during the most common furniture stripping processes.
  
  
• Assisting Furniture Strippers in Reducing the Risk from Methylene Chloride Stripping Formulations. National Institute for Occupational Safety and Health (NIOSH) In-Depth Survey Report, (1999, March 26). Provides a report detailing the effectiveness of several different ventilation systems in an effort to reduce methylene chloride exposures in furniture stripping operations. None of the ventilation systems were effective in controlling exposures below the OSHA PEL of 25 ppm.
  

Additional Information

Related Safety and Health Topics Pages

• Carcinogens
  


• Hazardous and Toxic Substances
  


• Sampling and Analysis
  


• Solvents

Training

• Most Frequently Cited Paragraphs of OSHA's Methylene Chloride Standard: 29 CFR 1910.1052. OSHA, (1999). Summarizes inspection results from 1997 through 1998 involving methylene chloride.
  

Other Resources

• Methylene Chloride. National Institute for Occupational Safety and Health (NIOSH) Workplace Safety and Health Topic.
  


• Methylene Chloride. National Institute of Standards and Technology (NIST) Chemistry WebBook. A comprehensive database with highly technical information, including thermochemical, thermophysical, and ion energetics data.

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