An acute inhalation toxicity study was conducted with groups of male and female albino Wistar rats (5/sex/group) receiving a single whole body exposure to 1,3-dichloropropane in a dynamic air flow chamber for 4 hours. Groups of animals were exposed to the test material at mean analytical concentrations of 29, 34, 42, 47 or 56mg/l, resulting in the following cumulative mortality data (no. animals dead/no. animals tested): 2/10, 4/10, 6/10, 9/10 and 10/10, respectively. Most of the deaths occurred on day 1 of the 14 day observation period. All animals were observed with increased respiratory rates within two hours of the start of the exposure. Gross necropsy of surviving rats revealed pale lower margins of the diaphragmatic lobes of the lungs. However, microscopic examination revealed no histopathological alterations. The acute inhalation LC50 of 1,3-dichloropropane was determined by Probit analysis to be 36mg/l (95% fiducial limits of 32 to 40mg/l).