Reproduction study with dibasic esters following inhalation in the rat

Groups of 20 male and 20 female Crl:CD(SD)BR rats were exposed to Dibasic Esters (DBE) at concentrations of 0 (control), 0.16, 0.40 (maximum attainable vapor), or 1.0 mg/L (aerosol). Exposures were conducted for 6 hours/day, 5 days/week for 14 weeks (pre-breeding) then 7 days/week for 8 weeks (through breeding, gestation, and lactation). The exposures were interrupted for female rats between gestation day 19 and postpartum day 3. Gestation day 1 was defined as the day a copulatory plug was found, postpartum day 1 was defined as the day of birth. No significant differences were observed between control and test rats with respect to mating performance, fertility, length of gestation, or progeny numbers, structure, and viability. Body weights of parental rats and of their offspring were reduced at 1.0 mg/L. The only histopathologic changes detected were in the nasal tissues of the parental rats, where an exposure-related increase in squamous metaplasia in the olfactory epithelium was observed. There was an increase in liver-to-body weight ratios in the two higher parental exposure groups and an increase in the lung-to-body weight ratio also seen at 1.0 mg/L. It is concluded that reproduction in rats was not altered by repeated inhalation exposure to up to 1.0 mg/L DBE, a concentration that produced both body weight and histologic effects in parental rats.