Long-term carcinogenicity bioassays on methylene chloride administered by ingestion to Sprague-Dawley rats and Swiss mice and by inhalation to Sprague-Dawley rats.
Methylene chloride was administered to Sprague-Dawley rats and Swiss mice by ingestion (stomach tube), in olive oil, at the doses of 500, 100 and 0 mg/kg body weight, once daily, 4-5 days weekly, for 64 weeks, and to Sprague-Dawley rats by inhalation, at the concentration of 100 and 0 ppm, 7 hours daily, for 5 days weekly. The inhalatory treatment was started on 13-week-old breeders, and male and female offspring (12-day embryos). The breeders and part of the offspring were exposed for 104 weeks; the other part of the offspring was exposed for 15 weeks only. The most important findings were: (1) the increased incidence of pulmonary tumors in male mice treated by ingestion at 500 mg/kg body weight; (2) a not-significant increase in total malignant tumors in rats exposed by inhalation at 100 ppm for 104 weeks; and (3) a not-significant increase in total malignant mammary tumors in female rats given methylene chloride by ingestion at 500 mg/kg body weight.
Maltoni
C
C
Institute of Oncology F. Addarii, Bologna, Italy.
Cotti
G
G
Perino
G
G
D000280:Administration, Inhalation; D000284:Administration, Oral; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000633:toxicity*; D008175:Lung Neoplasms / Q000139:chemically induced; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced; D008752:Methylene Chloride / Q000008:administration & dosage / Q000633:toxicity*; D051379:Mice; D009152:Mutagenicity Tests; D051381:Rats; D011919:Rats, Inbred Strains
D006843:Hydrocarbons, Chlorinated; D008752:Methylene Chloride