Methylene chloride (CH2Cl2), also known as dichloromethane, is one example of a class of chemicals known as chlorinated hydrocarbons. It has been used for paint and furniture stripping, as an extraction solvent in pharmaceutical manufacturing, as a solvent for metal cleaning and degreasing, and as a solvent in spray adhesive and urethane foam blowing.
Methylene chloride is a volatile, colorless liquid that has a chloroform-like odor. It has a boiling point of 104 deg. F and a vapor pressure of 350 mm at 68 deg. F (20 deg. C).
What are the hazards associated with methylene chloride?
The principal hazards associated with occupational exposure to methylene chloride are the health effects it produces. The primary routes of exposure to methylene chloride are by inhalation and direct contact with the skin and eyes.
Due to its high vapor pressure, methylene chloride can act as a simple asphyxiant by displacing air. It can also act as an anesthetic. Short term (acute) overexposure in air can result in mental confusion, dizziness, nausea and vomiting. At very high concentrations, exposure by inhalation can result in death. The IDLH (Immediately Dangerous to Life and Health) concentration for methylene chloride in air is 2300 parts per million. Studies of long term (chronic) exposure to methylene chloride suggest that methylene chloride is also a potential human carcinogen.
Regarding physical hazards, methylene chloride is classified as a combustible liquid. It has a lower explosive limit of 13 percent and an upper explosive limit of 23 percent. Combustion of methylene chloride can product phosgene, a deadly gas that can cause death.
What can I do to protect myself?
Whenever possible, employees should avoid using products that contain methylene chloride. In recent years, products containing 1-bromopropane, an unregulated chemical, have been substituted for those with methylene chloride. However, the use of 1-bromopropane has been shown to result in undesirable health effects.
- When workers must use methylene chloride-containing products, the work should be done is a well ventilated area. In addition, gloves appropriate for use with methylene chloride should also be worn to prevent direct contact.
What resources are available to assist employers?
Safety and Health Programs
These example programs, hazard communication, respiratory protection and the PPE hazard assessment can assist the employer with their hazard communication program and identifying the appropriate personal protective equipment required in the workplace.
Training and Outreach Services
Presentations on hazard communication, respiratory protection, and personal protective equipment (general industry and construction) can assist employers in training their staff. These presentations should be modified to address site-specific conditions and hazards.
In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request. These pre-recorded webinars on hazard communication, respiratory protection and toxic and hazardous substances can also be accessed at any time.
Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).
A-Z Safety and Health Topics
The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.
Which standards apply?
OSH has adopted the following standards for occupational exposure to methylene chloride in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic.
29 CFR 1910.1052 - methylene chloride
Maritime, Shipyard Employment
29 CFR 1915.1052 - methylene chloride
29 CFR 1926.1152 - methylene chloride
Additional standards associated with occupational exposure to methylene chloride include:
29 CFR 1910.132 - personal protective equipment; general requirements
29 CFR 1910.134 - respiratory protection
29 CFR 1910.1200 - hazard communication
Other Applicable Standards
The Which OSHA Standards Apply webpage can also help identify other standards that may be applicable to your worksite.
Where can I learn more?
Compliance Directive: CPL 02-02-070 (formerly CPL 2-2.70), Inspection Procedures for the Methylene Chloride Standard, establishes enforcement policy and provides an explanation of the standard to ensure uniform enforcement.
Industry Guide 48 - OSHA Construction Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for standards related to methylene chloride in construction.
Industry Guide 49 – OSHA General Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for standards related to methylene chloride in general industry.
Industry Guide 53 - OSHA Shipyard Employment Standards Requiring Programs, Inspections, Procedures, Records and/or Training highlights the requirements of standards related to methylene chloride in shipyard employment.
If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to email@example.com or by calling 919-707-7876.