Chronic toxicity and reproduction studies of hexachlorobutadiene in rats.
Hexachlorobutadiene (HCBD), while not produced commercially in the United States, may be encountered as an unwanted by-product of certain processes associated with the chlorination of hydrocarbons. Studies were conducted to assess the potential long-term toxicity of HCBD. In a reproduction study conducted in rats, dose levels of 20 or 2.0 mg/kg-day of HCBD induced slight maternal toxicity (primarily of the kidney) but caused no adverse effects on reproductive parameters-percent pregnancy and neonatal survival/development. A decreased neonatal body weight was noted at the highest dose level of 20 mg/kg-day of HCBD. No toxicologic effects were observed among the adults at a dose level of 0.2 mg/kg-day or among the neonates at dose levels of 0.2 or 2.0 mg/kg-day of HCBD. In a chronic toxicity study in rats, ingestion of 20 mg/kg-day for up to 2 years caused multiple toxicologic effects, primarily of the kidney, including the development of renal tubular adenomas and adenocarcinomas. Ingestion of the intermediate dose level of 2 mg/kg-day caused lesser degrees of toxicity, but no evidence of neoplasia. Ingestion of the lowest dose level of 0.2 mg/kg-day of HCBD caused no effects that could be attributed to treatment. These data indicate a dose-response relationship for HCBD-induced toxicity affecting primarily the kidney. HCBD-induced neoplasms occurred only at a dose level higher than that causing discernible renal injury.
D000230:Adenocarcinoma / Q000139:chemically induced; D000236:Adenoma / Q000139:chemically induced; D000818:Animals; D002070:Butadienes / Q000633:toxicity*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000633:toxicity; D007680:Kidney Neoplasms / Q000139:chemically induced; D007684:Kidney Tubules; D007928:Lethal Dose 50; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced; D011247:Pregnancy; D051381:Rats; D012098:Reproduction / Q000187:drug effects*
D002070:Butadienes; D006843:Hydrocarbons, Chlorinated; C001335:hexachlorobutadiene