N-Nitrosonornicotine (NNN) is a tobacco-specific nitrosamine produced during the curing and processing of tobacco. It has been classified as a Group 1 carcinogen. Although no adequate studies of the relationship between exposure to NNN and human cancer have been reported, there is sufficient evidence that NNN causes cancer in experimental animals.

N-Nitrosonornicotine (NNN) is a tobacco-specific nitrosamine produced during the curing and processing of tobacco. It has been classified as a Group 1 carcinogen. Although no adequate studies of the relationship between exposure to NNN and human cancer have been reported, there is sufficient evidence that NNN causes cancer in experimental animals.