NTP: Known to be a human carcinogen

Cancer classification (carcinogen classification) is a system by which hazardous substances are rated on their potential to cause cancer in humans. The classification is based mostly on animal studies and could change as scientific information improves. Several organizations determine cancer classifications. The classification listed below was published by the U.S. Department of Health and Human Services National Toxicology Program in its Report on Carcinogens.

The substances listed below have been proven scientifically to cause cancer in humans. This classification means that studies in humans have shown sufficient evidence of carcinogenicity, which indicates a causal relationship between exposure to the agent, substance, or mixture and human cancer.

Please contact NTPwith questions on cancer and cancer classification.