Subacute inhalation toxicity of mineral oils, C15-C20 alkylbenzenes, and polybutene in male rats.

Male Wistar rats were exposed to mist and vapor of two mineral oils, two C15-C20 alkylbenzenes, and one polybutene at aerosol concentrations of 70 mg.m-3 and 700 mg.m-3 for 2 weeks. Of oil mist particles, 82-97 wt% were respirable (less than 4.7 microns). High-level exposure to polybutene was lethal to three of four animals, due to pulmonary edema. Elevated numbers of pulmonary macrophages and increased macrophage vacuolization were observed after exposure to the polybutene, both mineral oils, and one alkylbenzene. The same alkylbenzene produced body weight loss. Deposition analysis was performed for one mineral oil. No oil was detected in brain tissue, while retroperitoneal fat tissue contained 541 (401-702) micrograms oil/g tissue, half of this still present after an exposure-free period of 2 weeks. It is concluded that inhalation of the polybutene and one of the mineral cable oils tested here produces toxic effects in lung.