Acute toxicity in the rat following either oral or inhalation exposure.

A survey of 108 chemicals was conducted to determine the relationship between acute oral and acute inhalation toxicity data in the rat. LD50 or LC50 values were compared after classification of each chemical in terms of relative toxicity. A positive correlation (0.53, P less than 0.001) between the classification of toxicity for the oral and inhalation routes was determined. However, the magnitude of this correlation was such that the predictive value of one for the other was limited. For a complete acute toxicity profile, it does not appear as if the determination of acute toxicity by one of those routes would yield a reliable estimate of toxicity by the other route.