Acute oral toxicity was evaluated in groups of 1 to 3 male and 1 to 4 female fasted albino Sprague-Dawley rats administered undiluted isopropanol by gavage at a level of 4.5, 5.8, 7.5 or 9.8 g/kg for males and 3.5, 4.5, 5.8 or 7.5 g/kg for females. Mortality was observed in 2/3 males in the 5.8 g/kg group, 3/3 in the 7.5 g/kg group and 1/1 in the 9.8 g/kg group and in 2/4 females in the 4.5 g/kg group, 2/2 in the 5.8 g/kg group and in 1/1 in the 7.5 g/kg group. The LD50 value was determined to be 5.3 g/kg for male rats and 4.5 g/kg for female rats. Clinical observations included soft stools, diarrhea, ataxia, decreased limb tone, hypoactivity, hypothermia, lacrimation, pinna and pain reflex absent, red-stained nose, mouth and eyes, brown-stained urogenital or anal region, dyspnea, bradypnea and piloerection. Gross necropsy revealed yellow-red stained perineum, red discharge around eyes, red areas on the thymus, perinasal discharge, stomach enlarged with gas, red mucosa, firm tan areas on the lungs and stomach and red kidney medulla.