Ethylene glycol monomethyl ether II. Reproductive and dominant lethal studies in rats

Groups of male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100, or 300 ppm ethylene glycol monomethyl ether (EGME) vapor 6 hours/day, 5 days/week for 13 weeks. The 0 and 30 ppm groups each contained 30 rats/sex and the 100 and 300 ppm groups each had 20 rats/sex. Following the exposure period, males were bred to unexposed females to evaluate reproductive capability and dominant lethality. Additional matings of control and 300 ppm exposed males were performed during the post-exposure period in order to evaluate the recovery of fertility. Exposed females were bred with unexposed males to assess reproductive parameters. Results of the present study indicate a potential for inhaled EGME to completely suppress fertility in male rats at the 300 ppm level. Fertility of these rats was partially restored at 13 weeks post-exposure. Body weights of animals in the 300 ppm group were reduced as a result of the exposures. No dominant lethal effect or impaired fertility was observed in male rats exposed to 30 or 100 ppm EGME. Treatment-related pathologic alterations were observed only in male rats at the 300 ppm level and induced decreased testicular size and atrophic seminiferous tubules. Female rats tolerated up to 300 ppm EGME without any adverse reproductive effects. Based on these results, it was concluded that the no-adverse effect level of EGME for fertility and reproduction was 100 ppm in rats.