Effect of 90-Day Continuous Exposure to Methyliso-butylketone on Dogs, Monkeys and Rats

Abstract : Continuous exposure of rats, dogs and monkeys to 410 mg/cu M methylisobutylketone vapor (MIBK) was conducted to evaluate the provisional spacecraft exposure limit of 20 ppm established by the Space Science Board, NAS/ NRC in 1968. The exposure conducted in a simulated space cabin environment did not produce any measurable changes in dogs or monkeys. Rats developed hyaline droplet nephrosis within 2 weeks of exposure which was reversible upon removal from the MIBK even after 90 days. The data obtained indicated that the 60- minute emergency exposure limit of 100 ppm and the 90- and 1000-day provisional limits as established by the Space Science Board contain a wide margin of safety.