The division consists of three sections which conduct a variety of research studies, mainly using rodents, including: subchronic toxicity tests; two-year carcinogenicity tests; modification of carcinogenicity study; and special toxicity, such as neurotoxicity and immunotoxicity for safety analysis of chemicals relating to environmental significance.

The division also performs the basic research on the mechanisms underlying chemically induced lesions, using such techniques as immunohistochemistry, in situ hybridization, molecular analysis with the laser capture tissue microdissection and also transgenic animal models.