Methylene Chloride

Methylene Chloride

Hazard Overview

Hazard Overview

What is methylene chloride?

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.

Solutions

Solutions

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?

Other applicable resources can be found on the A-Z topics pages for respiratory protection, hazard communication, and personal protective equipment. In addition, the NCDOL Library offers free safety and health videos and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC). 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.

Regulations

Regulations

Which standards apply?

OSH has adopted the following standards for occupational exposure to methylene chloride in North Carolina:

Additional standards associated with occupational exposure to methylene chloride include:

Learn More

Learn More

Where can I learn more?

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 ask.osh@labor.nc.gov or by calling 919-807-2875.