Rationale developed by the Environmental Protection Agency for the assessment of carcinogenic risks.

The intent of the Environmental Protection Agency's "Interim Guideline for Carcinogen Risk Assessment" is to provide an evaluation of the evidence regarding suspect carcinogens that encapsulates judgments on the quality and adequacy of data, the likelihood that the agent is a human carcinogen, and an estimate of the magnitude of the cancer burden that could be ascribed to the agent if no regulatory action were taken. Every effort shoult be made to reduce environmental contamination by carcinogens to the lowest possible level; this view stems from uncertainties about qualitative and quantitative extrapolations from animals to man, the lack of evidence for a dose threshold, the great range of possible interactions among environmental carcinogens and cofactors, and the broad spectrum of human susceptibility. New knowledge in the field of carcinogenesis is developing, and modifications of the Environmental Protection Agency's "Interim Guideline for Carcinogen Risk Assessment" must be made periodically.