ABSTRACT
This chapter presents several components, with particular attention to applications of toxicokinetic data to inform the risk assessment process. It focuses on non-cancer risk assessment, cancer risk assessment, particularly in the context of noting similarities and differences between the approaches for noncancer and cancer endpoints. Risk characterization is the most important and final part of a risk assessment. It summarizes and interprets the information from hazard identification, and exposure steps, often by quantitatively comparing exposures with doses that are associated with potential health effects. The risk per unit dose continues to be used for chemicals that are believed to act via processes that would be expected to exhibit a linear dose–response at low doses. The uncertainties identified in each step in the risk assessment process are analyzed and the overall impact on the risk estimate is evaluated quantitatively and/or qualitatively. For carcinogens that act via mode of action that generate nonlinear responses, risk characterization is done as for noncancer endpoints.
