Synonyms: Methylene dichloride; Dichloromethane

OSHA IMIS Code Number: 1730

Chemical Abstracts Service (CAS) Registry Number: 75-09-2

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: PA8050000

Department of Transportation Regulation Number (49 CFR 172.101) and 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]: 1593 160

NIOSH Pocket Guide to Chemical Hazards - Methylene Chloride: Chemical description, physical properties, potentially hazardous incompatibilities, and more

U.S. Environmental Protection Agency (EPA) Hazard Summary - Methylene Chloride: Uses, sources and potential exposure, acute and chronic health hazard information, and more

National Toxicology Program (NTP) carcinogenic classification: Reasonably anticipated to be a human carcinogen [15 MB PDF, 507 pages]

International Agency for Research on Cancer (IARC) carcinogenic classification: Group 2B [380 KB PDF, 171 pages] (possibly carcinogenic to humans)

EPA carcinogenic classification: Likely to be carcinogenic to humans

EPA Inhalation Reference Concentration (RfC): 0.6 mg/m³

Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Levels (MRLs): 0.6 ppm (acute); 0.3 ppm (intermediate); 0.3 ppm (chronic)

NIOSH Immediately Dangerous to Life or Health (IDLH) concentration: 2,300 ppm

Notes on Other Potential Health Effects and Hazards

1. Combustible under specific conditions. Gives off irritating or toxic fumes (or gases) in a fire (NIOSH/IPCS 1994).
2. Case studies of methylene chloride poisoning during paint-stripping operations have demonstrated that inhalation exposure can be fatal to humans (ATSDR 2000).
3. Thirteen deaths of bathtub refinisher fatalities associated with methylene chloride stripping agents have occurred during 2000-2011. Each death occurred in a residential bathroom with inadequate ventilation (CDC 2012).
4. NTP concluded that methylene chloride administered by inhalation caused liver, lung, and breast tumors, which was sufficient evidence to classify methylene chloride as reasonably anticipated to cause cancer.
5. The EPA reference concentration was established based on liver effects in a laboratory inhalation study in rats.

Date Last Revised: 12/11/2012

Literature Basis:

• ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Dichloromethane. 2001.
• ATSDR: Toxicological Profile for Methylene Chloride [3 MB PDF, 313 pages]. September 2000.
• ATSDR: Toxicological Profile Addendum - Methylene Chloride [123 KB PDF, 17 pages]. July 2010.
• EPA IRIS Methylene Chloride, 2011.
• CDC: Fatal exposure to methylene chloride among bathtub refinishers - United States, 2000-2011. MMWR Morb Mortal Wkly Rep. 61(7):119-22, 2012.
• OSHA: Occupational Safety and Health Standards, Substance Safety Data Sheet and Technical Guidelines for Methylene Chloride. 1910.1052 App A.
• OSHA: Occupational Safety and Health Standards, Medical Surveillance for Methylene Chloride. 1910.1052 App B.
• NIOSH: Occupational Health Guideline for Methylene Chloride. 1976.
• NIOSH/IPCS: International Chemical Safety Cards - Methylene Chloride. April 22, 1994.
• NTP 12th Report on Carcinogens Dichloromethane, 2011 [140 KB PDF, 3 pages]

Laboratory Sampling/Analytical Method:

• sampling media: Carbosieve S-III Tube (130/65 mg sections, 60/80 mesh)
  analytical solvent: (99:1) Carbon Disulfide/Dimethylformamide
  maximum volume: 3 Liters
  maximum flow rate: 0.05 L/min (TWA)
  minimum time: 5 Minutes
  maximum flow rate: 0.05 L/min (Ceiling or STEL)
  minimum time: 5 Minutes
  maximum flow rate: 0.05 L/min (Peak)
  current analytical method: Gas Chromatography; GC/FID
  method reference: OSHA Analytical Methods (OSHA 80)
  method classification: Fully Validated


• sampling media: Charcoal Tube (350/350/350 mg sections, 20/40 mesh)
  analytical solvent: Carbon Disulfide
  alternative solvent: (99:1) Carbon Disulfide/Dimethylformamide
  maximum volume: 10 Liters
  maximum flow rate: 0.05 L/min (TWA)
  minimum time: 5 Minutes  
  maximum flow rate: 0.05 L/min (Ceiling or STEL)
  minimum time: 5 Minutes
  maximum flow rate: 0.05 L/min (Peak)
  minimum time: 5 Minutes
  maximum flow rate: 0.05 L/min (Peak)
  current analytical method: Gas Chromatography; GC/FID
  method reference: OSHA Analytical Methods (OSHA 59)
  method classification: Fully Validated

** All Trademarks are the property of their respective owners.

Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF materials.