Experimental human exposure to methylene chloride.

Abstract

Inhalation of methylene chloride vapor In concentrations of 500 to 1,000 ppm for one to two hours was followed promptly by a sustained elevation of carboxyhemoglobin level in all 11 subjects studied. The evidence suggests that carbon monoxide may fee a metabolite of methylene chloride and that exposure to concentrations of methylene chloride that do not exceed the Industrial Threshold Limit Value for that solvent may result in a carboxyhemoglobin saturation level in excess of that allowable from carbon monoxide itself. In addition, methylene chloride produced signs and symptoms of central nervous system depression in subjects exposed to vapor concentrations of 1,000 ppm.