Dichloromethane Fact Sheet

Source of Exposure

Dichloromethane, also known as methylene chloride is a major component of paint strippers and degreasers. It also is used as a solvent for oils, fats, and waxes. NIOSH estimates that over 70,000 workers a year are exposed to dichloromethane. Exposure generally occurs through inhalation of vapors but may occur through oral ingestion as well.

Symptoms

The toxic effects of methylene chloride are evident in the impairment of the central nervous system. Exposure can cause headaches, loss of coordination, gastrointestinal problems, irritation of mucous membranes, and dermatitis.

Blood Concentrations

The data shows background levels for dichloromethane in the general population to be 0.7 PPB in whole blood. The Threshold Limit Value set for ambient air is 100,000 PPB. Blood studies that correlate blood levels with the TLV are not available at this time.

Toxic Levels

Exposure to dichloromethane is known to carry an increased risk of cancer. Individuals who have been sensitized may manifest negative health effects at concentrations well within the ranges considered safe for the average population. (See Chemically Sensitive Patients.)

Metabolism

Individuals who have been exposed have produced increased levels of carboxyhemoglobin. As methylene chloride is metabolized in the body, it produces carbon monoxide.

Summary

Classification:   Halogenated Hydrocarbon
Population Average:   0.7 PPB (whole blood)
Threshold Limit Value:   100,000 PPB (air)
Onset of Symptoms:   Data not available
Death:   Data not available
Half Life:   Data not available
LD5O:   (oral-rat) 167 mg/kg

References

-Alessio, L., Berlin, A., Roi, R., and Boni, M. (Eds.), Human biological monitoring of industrial chemicals series, Luxemberg, Commission of European Communities, 1983.

-Baselt, R.D. Disposition of Toxic Drugs and Chemicals in Man, Davis, CA: Biomedical Publications, 1982.

-Clayton, G.D. and Clayton, F.E., Patty's Industrial Hygiene and Toxicology, vol. 2B, 3rd ed., Wiley-Interscience, New York, 1981.

-Doull, J. et al., Casarett and Doull's Toxicology, 2nd ed., Macmillan, New York, 1980.

-Last, J.M., Maxcy-Rosenau Public Health and Preventive Medicine, 11th ed., Appleton-Century-Crofts, New York, 1980.

-Plunkett, E.R., Handbook of Industrial Toxicology, Chemical Publishing Co., New York, 1 76.

-Sax, N.I., (Ed), Dangerous Properties of Industrial Materials Report, 6th Ed., New York . Van Nostrand Reinhold Co., 1984.

-Seba, D. B., Milam, M. J. and Laseter , J. L., "Uptake, measurement and elimination of synthetic chemicals by man", in Brostoff, J. and Challacombe, S.J. (Eds), Food Allergy and Intolerance, London: Bailliere Tindall,, 1987.