ABSTRACT
This chapter addresses the following questions through the use of several examples in which the route of administration has been shown to be a factor relevant to understanding the toxic potential associated with a chemical exposure. The first question is what variations in toxicity might result when similar routes of administration are employed across species lines? The second question is what variations in toxicity may occur when different routes of administration are employed for a chemical within or across species lines? An appreciation of the potential similarities and differences between species with respect to the role of the route of administration in expression of chemical toxicity is an important element in the extrapolation of animal toxicity data to man. Agents which are potent irritants may produce their primary toxic effect at the site of application, for example, the upper respiratory tract, skin, or gastro-intestinal tract. Formaldehyde is an example of an inhaled toxicant with a widespread environmental distribution.
