N-Nitrosodimethylamine (CHEM000177)

N-Nitrosodimethylamine is found in pepper (Capsicum annuum). N-Nitrosodimethylamine is a food contaminant especially in cured meat products. N-Nitrosodimethylamine (NDMA), also known as dimethylnitrosamine (DMN), is a semi-volatile organic chemical that is highly toxic and is a suspected human carcinogen. The US Environmental Protection Agency has determined that the maximum admissible concentration of NDMA in drinking water is 7 ng L 1. The EPA has not yet set a regulatory maximum contaminant level (MCL) for drinking water. At high doses, it is a potent hepatotoxin that can cause fibrosis of the liver in rats. The induction of liver tumors in rats after chronic exposure to low doses is well-documented. Its toxic effects on humans are inferred from animal experiments but not well-established experimentally. NDMA is an industrial by-product or waste product of several industrial processes. It first came to attention as a groundwater contaminant in California in 1998 and 1999 at several sites that produced rocket fuel. Manufacturing of unsymmetrical dimethylhydrazine (UDMH), which is a component of rocket fuel that requires NDMA for its synthesis, proved to be the culprit in these cases. Of more general concern, water treatment via chlorination or chloramination of organic nitrogen-containing wastewater can lead to the production of NDMA at potentially harmful levels. Further, NDMA can form or be leached during treatment of water by anion exchange resins. Finally, NDMA is found at low levels in numerous items of human consumption including cured meat, fish, beer, and tobacco smoke It is, however, unlikely to bioaccumulate. N-nitrosodimethylamine belongs to the family of Nitrosamines. These are compounds containing the nitrosamine functional group, with the structure R2NNO.