Ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME): Inhalation fertility and teratogenicity studies in rats, mice and rabbits

Abstract

A combined dominant lethal-fertility study was conducted in which male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100 or 300 ppm of ethylene glycol monomethyl ether (EGME) vapor for 6 hr/day, 5 days/week for 13 weeks and then mated to untreated counterparts. Among males, fertility was completely suppressed after exposure to 300 ppm. A partial restoration of reproductive function was evident following 13 weeks of recovery. No treatment-related reproductive effects were observed among males exposed subchronically to 100 ppm, or among females exposed to 300 ppm or below of EGME. Studies to assess the effects of inhaled EGME on embryonal and fetal development were also conducted in Fischer 344 rats,CF-1 mice, and New Zealand White rabbits. Rats and rabbits were exposed to concentrations of 0, 3, 10 or 50 ppm for 6 hr/day on days 6-15 or 6-18 of gestation, respectively. Exposure of rabbits to 50 ppm resulted in significant teratologic effects, an increased resorption rate, and decreased fetal body weight. Slight fetotoxicity in the form of skeletal variations were observed among rats exposed to 50 ppm. Exposure of pregnant mice to 0, 10 or 50 ppm for 6 hr/day on days 6-15 of getation resulted in slight fetotoxicity at 50 ppm. No significant treatment-related effects were observed at 10 ppm of EGME or below in anyof the species tested. Separate groups of pregnant rats and rabbits were exposed to 0, 500, 1500 or 3000 ppm of propylene glycol monomethyl ether (PGME) during organogenesis. Mild CNS depression was observed among rats and rabbits exposed to 3000 ppm of PGME. Fetal examination revealed no embryotoxic or teratogenic effects among either species. Delayed sternebral ossification observed among rats exposed to 3000 ppm of PGME was considered indicative of only slight fetotoxicity. Thus, it was concluded that PGME was not teratogenic at exposure levels up to 3000 ppm.