DEVELOPMENTAL TOXICITY OF DIBASIC ESTERS BY INHALATION IN THE RAT

Dibasic esters (DBE) are a mixture of 3 carboxylic acid esters which a re used in the paint and coatings industry. In this study, groups of p regnant Crl:CD(R)BR rats were exposed to either 0.16, 0.4, or 1.0 mg D BE/L by inhalation for 6 hr/day from Days 7 through 16 of gestation (d ay in which copulation plug was detected was designated Day 1G). A con trol group of chambered pregnant rats was exposed simultaneously to ai r only. All female rats were euthanized on Day 21G and the fetuses wer e examined. A suppression of both food consumption and the rate of bod y weight gain was seen in the 0.4 and 1.0 mg/L groups during the first 6 exposure days. Staining on the fur and perineal area was seen in ra ts exposed to 1.0 mg/L and liver weight decreases, although not statis tically significant, occurred in the 2 high exposure groups. None of t he reproductive parameters were altered in any of the groups and no fe tal effects were detected. DBE is not a developmental toxin in the rat following inhalation exposures as high as 1.0 mg DBE/L during the per iod of organogenesis.