Final report on the developmental toxicity of naphthalene (CAS No. 91-20-3) in New Zealand White (trade name) rabbits. Rept. for 26 Mar-1 Aug 91

Naphthalene (NAP) is a polyaromatic hydrocarbon produced from petroleum and coal tar. NAP is widely used in the manufacture of dyes, synthetic tanning agents, and lubricants; it is also a common constituent of mothballs. Exposure to NAP can occur in the home and workplace, and ingestion or inhalation can cause severe toxicity in humans, especially in infants and individuals with a deficiency in the enzyme glucose-6-phosphate dehydrogenase. Because of the large population at risk, and since NAP readily crosses the placenta, it was evaluated as a developmental toxicant. Accordingly, NAP (0, 20, 80, or 120 mg/kg/day) was administered in corn oil by gavage to pregnant rabbits during the major period of organogenesis (gd 6-19). Maternal clinical signs, weight, and food consumption were monitored from gd 0 to 30. On gd 30, fetuses were removed from the does and examined for effects of NAP on growth, viability, and morphological development. The results from the study provide no definitive evidence for NAP being toxic to the fetus or doe at doses as high as 120 mg/kg/day. Higher doses were not examined in the study due to the reported incidence of 40% maternal mortality following administration of 150 mg/kg/day NAP to pregnant rabbitsmore » in a range-finding study.« less