Diethylene glycol monomethyl ether 13-week vapor inhalation toxicity study in rats

Male and female Fischer 344 rats were exposed to 0, 30, 100, or 216 ppm diethylene glycol monomethyl ether (DEGME) vapors (0, 0.15, 0.49, or 1.06 mg/liter) 6 hr/day, 5 days/week, for 13 weeks. The 216-ppm exposure level was the maximum practically attainable concentration, and it was more than 60% of the theoretical maximum vapor concentration for DEGME at 25 degrees C and 1 atm pressure. Body weights, organ weights, hematological analyses, clinical chemistry analyses, urinalyses, and gross and histopathological examinations revealed no indication of a treatment effect in either male or female rats. Based on the absence of treatment-related effects in this study and the low vapor pressure of the material, DEGME should not present the same degree of inhalation hazard as its structural homolog, ethylene glycol monomethyl ether.