Toxicology and Carcinogenesis Studies of Ethylene Thiourea (CAS No. 96-45-7) inF344/N Rats and B6C3F1 Mice (Feed Studies)

摘要

Toxicology and carcinogenicity studies were conducted by administering dietaryconcentrations of 0, 25, 83, and 250 ppm ethylene thiourea to groups of 60 F344/N rats of each sex. Dietary concentrations of 0, 100, 330, and 1,000 ppm ethylene thiourea were administered to groups of 60 B6C3F1 mice of each sex during these 2-year studies. Under the conditions of these 2-year adult-only dietary exposures, there was clear evidence of carcinogenic activity of ethylene thiourea in male and female F344/N rats, as shown by increased incidences of thyroid follicular cell neoplasms. There was clear evidence of carcinogenic activity of ethylene thiourea in male and female B6C3F1 mice as shown by increased incidences of thyroid follicular cell neoplasms, hepato-cellular neoplasms, and adenomas of the pars distalis of the pituitary gland.