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 Diba sic Esters (DBE) at concentrations of 0 (control), 0.16, 0.40 (maximum attainable vapor), or 1.0 mg/L (aerosol). Exposures were conducted fo r 6 hours/day, 5 days/week for 14 weeks (pre-breeding) then 7 days/wee k for 8 weeks (through breeding, gestation, and lactation). The exposu res were interrupted for female rats between gestation day 19 and post partum day 3. Gestation day I was defined as the day a copulatory plug was found, postpartum day I was defined as the day of birth. No signi ficant differences were observed between control and test rats with re spect to mating performance, fertility, length of gestation, or progen y 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, wher e an exposure-related increase in squamous metaplasia in the olfactory epithelium was observed. There was an increase in liver-to-body weigh t 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 expos ure to up to 1.0 mg/L DBE, a concentration that produced both body wei ght and histologic effects in parental rats.