Health Assessment Document for Dichloromethane (Methylene Chloride)
Archived files are provided for reference purposes only. The file was current when produced, but is no longer maintained and may now be outdated. Persons with disabilities having difficulty accessing archived files may contact the NCEA Webmaster for assistance. Please visit http://epa.gov/ncea to access current information.
Dichloromethane (methylene chloride) is known to be metabolized to carbon monoxide in man and animals, primarily by the liver. Because the oxygen content of blood is decreased, depriving the brain and heart of the oxygen they require, serious permanent damage may result. Carboxyhemoglobin is formed from the interaction of carbon monoxide and hemoglobin. Persons exposed to levels of dichloromethane that do not exceed the industrial standard of 500 ppm may have blood carboxyhemoglobin levels that exceed those allowable from direct exposure to carbon monoxide. The adverse health effects associated with dichloromethane exposure are primarily neurological and cardiovascular. There is evidence that exposure can result in hemolytic anemia, especially among those individuals with erythrocytes deficient in glucose-6-phosphate dehydrogenase. The observed cardiotoxic properties include cardiodepression and cardiosensitization. Nonfatal exposures have caused EKG changes similar to those caused by carbon monoxide.