Nitrosamine

  Nitrosamines are chemical compounds of the chemical structure R₁N(-R₂)-N=O, some of which are carcinogenic.

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Occurrence in food

Nitrosamines are produced from nitrites and secondary amines, which often occur in the form of proteins. Their formation can occur only under certain conditions, including strongly acidic conditions such as that of the human stomach. High temperatures, as in frying, can also enhance the formation of nitrosamines.

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

Nitrosamines are found in many foodstuffs, especially beer, fish, and fish byproducts, and also in meat and cheese products preserved with nitrite pickling salt. The U.S. government established limits on the amount of nitrites used in meat products in order to decrease cancer risk in the population. There are also rules about adding ascorbic acid or related compounds to meat, because they inhibit nitrosamine formation.

Occurrence in other consumer products

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.^[1] However, nitrosamines from condoms are not expected to be of toxicological significance.^[1]

Cancer

Nitrosamines can cause cancers in a wide variety of animal species, a feature that suggests that they may also be carcinogenic in humans. Epidemiological data suggest that nitrosamines in preserved food cause stomach cancer.^[2]

Uses^{[citation needed]}

• Rubber products
• Pesticides
• Certain cosmetics

Examples of nitrosamines

Tobacco-specific nitrosamines

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

Other nitrosamines

• NDEA
• NDMA

References

1. ^ Proksch E. Toxicological evaluation of nitrosamines in condoms. Int J Hyg Environ Health. 2001 Nov;204(2-3):103-10. PubMed
2. ^ Jakszyn P, Gonzalez CA. Nitrosamine and related food intake and gastric and oesophageal cancer risk: a systematic review of the epidemiological evidence. World J Gastroenterol. 2006 Jul 21;12(27):4296-303. PubMed

See also

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