Pregnant rats in two studies were exposed by inhalation to 0, 1, 10, and 25 ppm of β-chloroprene for 4 hr daily. Dams in one study (50 per group) were exposed on Days 1 through 12 and sacrificed on Day 17 to evaluate the embryotoxic potential of β-chloroprene. Dams in a teratology study (25 per group) were exposed on Days 3 through 20 and sacrificed on Day 21 of gestation. Male rats in a reproduction study were exposed to 25 ppm or β-chloroprene, 4 hr daily for 22 days and bred with untreated virgin females (three new females per male each week) for 8 consecutive weeks. No maternal, embryonal, or fetal toxicity was observed in the first two studies at levels of 1, 10, or 25 ppm β-chloroprene. Maternal exposure to β-chloroprene did not affect the development of rat fetuses as measured by weight and crownrump length and did not result in major external, skeletal, or soft tissue malformations. The reproductive capability of males exposed to 25 ppm of β-chloroprene 4 hr daily for 22 days was not impaired. The results of these studies indicate that 25 ppm of β-chloroprene, the present threshold limit value, is not embryotoxic or teratogenic and does not impair reproductive capability of male rats. These results are at variance with previous findings from the Soviet Union. © 1978.
Culik, R., Kelly, D. P., & Clary, J. J. (1978). Inhalation studies to evaluate the teratogenic and embryotoxic potential of β-chloroprene (2-chlorobutadiene-1,3). Toxicology and Applied Pharmacology, 44(1), 81–88. https://doi.org/10.1016/0041-008X(78)90286-7