chapter  17
35 Pages

Mechanistic considerations in the regulation and classification of chemical carcinogens

CARCINOGENICITY TESTING Most drugs, pesticides, and food and color additives require carcinogenicity testing in two rodent species prior to marketing approval. Carcinogenicity testing is the most time-and resource-intensive aspect of toxicity testing and is also the most difficult test with respect to the interpretation of the significance of positive findings. This is of considerable consequence because of the high proportion of tested compounds that are "positive" in at least one species or sex in the rodent carcinogenicity test.