8-HYDROXYQUINOLINE RODENT STUDIES SHOW "NO EVIDENCE OF CARCINOGENICITY," HHS'

8-HYDROXYQUINOLINE RODENT STUDIES SHOW "NO EVIDENCE OF CARCINOGENICITY," HHS' Natl. Toxicology Program stated in a July 8 Federal Register notice announcing the availability of a technical report on the rodent testing. The compound is an off-white to white crystal or crystalline powder used as an analytical reagent and an antimicrobial agent in medicine, fungicides, and insecticides; as a preservative in cosmetics and tobacco; a chemical intermediate in dye synthesis; and a precipitating reagent in nuclear power plant liquid waste effluent, the notice says. NTP conducted carcinogenesis studies of 8-hydroxyquinoline, at a purity of 99%, by administering the chemical in feed to groups of 50 male and 50 female rats and mice at concentrations of 0, 1,500, or 3,000 ppm for 103 weeks. "These concentrations were selected because the chemical at higher concentrations resulted in reduced feed consumption, decreases in mean body weights, and deaths in the 15-day and 13-week studies," the notice says. Average daily doses were estimated to be 73 and 143 mg/kg for male rats, 89 and 166 mg/kg for female rats, 217 and 396 mg/kg for male mice, and 349 and 619 mg/kg for female mice. None of the animals developed cancer over two years at the concentrations of the chemical given, NTP says. Copies of the technical report -- - "Toxicology and Carcinogenesis Studies of 8-Hydroxyquinoline in F344/N Rats and B6C3Fl Mice (Feed Studies) (T.R. 276)" -- are available free of charge from the NTP Public Information Office, M.D. B2-04, P.O. Box 12233, Research Triangle Park, North Carolina 27709, 919/541-3991 or FTS: 629-3991.