English

Noun

nitrosamine

1. a divalent functional group, >N.N=O
2. a class of organic compounds containing this group; prepared by the reaction of amines with nitrites; they are carcinogenic

Derived terms

• dimethylnitrosamine

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

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. When animal protein like red meat, poultry or fish are cooked too close to a flame (barbecue) or in contact with a hot metallic surface (grilling) the amino-acids in those proteins turn into nitrosamines which are highly carcinogenic substances. This cooking styles may be responsible for thousands of cases of colon cancer per year across the world.

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.http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15672455 However, nitrosamines from condoms are not expected to be of toxicological significance.

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.

Uses

• 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

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