TOXICOLOGICAL ASPECTS OF CYCLOHEXANONE

A toxicity evaluation of cyclohexanone was conducted using oral, intraperitoneal, dermal, intradermal, ophthalmic, and/or inhalation exposure to various species of animals. Cyclohexanone induced diverse reactions by virtue of a general vascular or tissue reaction and CNS depression. The ip LD50 for mice, rats, guinea pigs, and rabbits ranged from 0.93 to 1.54 g/kg, with guinea pigs being most sensitive. Intragastrically, the LD50 values were about 1.8 and 2.1 g/kg for rats and mice, respectively, with no significant differences between sexes. Inhalation exposure of mice to cyclohexanone (∼ 19 mg/liter) resulted in a mean time to death (LT50) of 99.9 min. Histological examination of lungs revealed acute congestion and edema with focal to diffuse hemorrhage of the lung parenchyma. Cyclohexanone behaved as a primary irritant intradermally, dermally, and ophthalmically. It was cytotoxic to mouse fibroblast cells in culture and produced a negative inotropic effect upon the isolated perfused rabbit heart. Three-day pretreatment with cyclohexanone did not significantly alter pentobarbital sleeping time of mice. Repeated ip administration exhibited a cumulative toxic effect in mice. © 1979.