Nitrosamines are carcinogenic chemical compounds of the chemical structure R₂N-N=O. Nitrosamines are produced from nitrites and amines. Their formation can occur only under certain conditions, including strongly acidic conditions such as that of the human stomach.

The nitrite forms nitrous acid (HNO₂), which splits into the nitrosyl cation (N=O⁺) and the hydroxide (OH^-) anion. The nitrosyl cation then reacts with an amine to produce nitrosamine.

Nitrosamines are found in many foodstuffs especially beer, fish, fish byproducts, and in meat and cheese products preserved with nitrite pickling salt. They are formed when the food protein reacts with nitrite salts in the stomach. They can also be formed by frying or smoking. The rule of thumb is: nitrosamine-content is lower if the food has been processed less, fewer preservatives used, and natural production techniques used.

Cancer

Nitrosamines can cause cancers in animals and humans. For example nitrosamines can be produced in tobacco smoke by the interaction of nicotine and other compounds with nitrite in the tobacco. Many of the nitrosamines are carcinogenic in a wide variety of species, a feature which suggests that they may also be carcinogenic in man. Subtle changes in the structure of nitrosamines produce cancer in various organs. Nitrosamines can be produced in man and other mammals under the acidic conditions that exist in the stomach by the reaction of nitite and secondary amines, compounds that are found in therapeutic drugs, agricultural and industrial chemicals. The reduction of the nitrite content of foods, for example in sausages, may reduce the formation of these compounds in man. Ascorbic acid (vitamin C) or similar compounds (erythorbate) are added to bacon, preserved meats and sauages to reduce the formation of nitrosamines in these foods.

Uses

• Fried bacon & Cured meats
• Beer & Nonfat dry milk
• Tobacco products
• Rubber products
• Pesticides
• Certain cosmetics

Food industry

The US government established limits on the amount of nitrites used in meat products to decrease cancer risk in the population. There are also rules about adding ascorbic acid or isomers thereof to meats for they inihibit the production of nitrites. (3)

Latex

Nitrosamines can be found in tobacco smoke and latex products. A test of party balloons and condoms indicated that many of them release small amounts of nitrosamines.^{However, nitrosamines from condoms are not expected to be of toxicological significance.[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11759152}

Examples of nitrosamines

Tobacco-specific nitrosamines

• N-Nitrosonornicotine (NNN)
• NNK
• NNAL
• NAT
• NAB
• iso-NNAL
• iso-NNAC

Other nitrosamines

• NDEA
• NDMA

See also

• Nitroamine (without the 's'), compounds of the formula R₂N-NO₂.
• Nitroso, compounds of the formula R-NO

External links

• Oregon State University, Linus Pauling Institute article on Nitrosamines and cancer, including info on history of meat laws
• Risk factors in Pancreatic Cancer

Nitrogen metabolism | Functional groups

Nitrosamine | 亚硝胺