Nnitrosamines

N-nitrosamines are a class of organic compounds that contain the nitrosamine functional group, in which a nitroso group is bound to the nitrogen atom of a secondary or tertiary amine. They can be represented by a general structure such as R1R2N–N(–R3)–NO, where the R groups are alkyl or aryl substituents. N-nitrosamines are typically formed by nitrosation, a reaction in which nitrite under acidic conditions reacts with amines to yield the N-nitrosamine.

Common sources and occurrence include processed meats, tobacco smoke, beer and other fermented beverages, and drinking water, where nitrite ions and amine precursors may be present. Well-known members of this class include N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA). They can form during food processing, storage, and certain industrial or chemical reactions.

Health effects and toxicology: many N-nitrosamines are carcinogenic in animals, and several are considered probable or possible carcinogens for humans by international agencies. The toxic mechanism often involves metabolic activation by liver enzymes to electrophilic species that can alkylate DNA, contributing to cancer risk in multiple organs.

Regulation, detection, and mitigation: regulatory bodies monitor nitrosamines in foods, drinking water, and pharmaceuticals and set limits to reduce exposure. Detection typically employs gas chromatography–mass spectrometry or liquid chromatography–mass spectrometry. Mitigation strategies include reducing nitrite use in curing processes, adding antioxidants such as ascorbic acid, controlling processing conditions to minimize nitrosation, and using treatment methods to remove nitrosamines from water.