Abstract |
In the initial portion of the study, rats were exposed for a single six hour period to concentrations of the test compound in air ranging from 25 to 100 mg/1. Death occurred at all concentrations above 25 mg/1. All animals in the 25 mg/1 group (3 males and 3 females) survived to day 16 with only slight decreased activity in days 1-2 noted. In the repeated dose portion of the study, rats were exposed to repeated six hour exposures at concentrations of 15 and 25 mg/1. The study was designed for 10 repeated inhalation exposures. However, all animals either died or were sacrificed by day 4. Those that survived on day 4 showed incoordination with one animal in the 25 mg/1 displaying a sustained convulsion and one in both groups exhibiting slight to moderate tremors. We believe the animals exhibiting convulsion and tremors were moribund. Histopathology of the 15 mg/1 repeated dose animals showed slight to mild centrilobular hepatocellular vacuolation in 6 of 10 animals. An increase in mitotic figures were in noted in most lesions. Mild squamous metaplasia of the transitional epithelium of the nasal passages were observed in all rats. Slight to moderate degeneration/necrosis of the olfactory epithelium and/or Bowman's gland necrosis were also noted. |