What major does toxicology belong to?

Preventive medicine major.

Toxicology is a subject that studies the effects of exogenous substances on organisms and evaluates their toxic effects qualitatively and quantitatively. Its research purpose is to provide scientific basis for protecting the health or safety of organisms, which belongs to preventive medicine and runs through the idea of prevention first. In the actual specialty setting of universities, toxicology and pharmacology are often set in the same specialty.