The purpose of the study was to evaluate the toxicity of isobutyl alcohol in a rat subchronic toxicity study. Four groups of male and female rats (30/sex/group) were dosed orally once daily with 0, 100, 316, or 1000 mg/kg/day of compound until the day of necropsy at an interim sacrifice (days 29 and 30) or a final sacrifice (days 92 and 93). Oral administration of isobutyl alcohol produced treatment-related effects at a dose level of 1000 mg/kg/day, but not at dose levels of 100 or 316 mg/kg/day. At the 1000 mg/kg/day dose level, hypoactivity was observed in all rats and body weight gain in the males was 18% below the control average during week 1. Food consumption averages were below those of the controls for both males and females during weeks 1 and 2. In addition, serum potassium averages were 11-15% below control averages (both sexes) at the interim evaluation and this may have been a small transitory effect related to treatment.