What are the main health hazards associated with breathing in methylene chloride?
Methylene chloride can cause slight irritation and mild central nervous system (CNS) depression. Slight irritation of the nose and throat were noted in one study after exposure to 500 ppm for 1 hour. However, in another study, no irritation was noted following exposures to concentrations from 515 ppm (1 hour) to 986 ppm (2 hrs). No effects were seen when volunteers were exposed to 213 ppm for 60 minutes. Mild CNS effects (headache, dizziness) were seen in volunteers exposed to concentrations as low as 200 ppm for 2-3 hours or 986 ppm for 1 hour. Other signs of mild CNS depression such as dizziness, nausea, inability to concentrate, and reduced coordination have been reported in numerous case reports, usually when methylene chloride was used in poorly ventilated areas. In more severe cases, methylene chloride has caused serious CNS depression including unconsciousness and respiratory failure as well as pulmonary edema and death. Metabolism of methylene chloride to carbon monoxide (which
