NTP Technical Report on the Toxicology and Carcinogenesis Studies of Isobutene211 (CAS No. 115-11-7) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)

摘要

Isobutene is produced during the fractionation of refinery gases or through the211u001ecatalytic cracking of methyl-t-butyl ether. Isobutene is primarily used to 211u001eproduce diisobutylene, trimers, butyl rubber, and other polymers. In addition, it 211u001eis used in the production of isooctane, high-octane aviation gasoline, methyl-t-211u001ebutyl ether, and copolymer resins with butadiene and acrylonitrile. Isobutene was 211u001eselected for evaluation because of the potential for human exposure due to its 211u001elarge production volume and the lack of adequate data on its carcinogenic 211u001epotential. The toxicity and carcinogenicity of isobutene were determined in male 211u001eand female F344/N rats and B6C3F1 mice exposed to isobutene (greater than 98% 211u001epure) by inhalation for 14 weeks or 2 years. The mutagenicity of isobutene was 211u001eassessed in Salmonella typhimurium, and the frequency of micronuclei was 211u001edetermined in the peripheral blood of mice exposed by inhalation for 14 weeks.