Nitrite

Occurrence in nature: Nitrite exists as a salt with sodium or potassium and is present in trace amounts in plants and animals.

Occurrence in tobacco: Nitrate is present in rather high concentrations in the tobacco plant as well as in other plants. Under certain conditions, nitrite can be formed from nitrate during drying and preparation of tobacco

Occurrence in foodstuffs: The concentration of nitrite in vegetables and cereals is generally low.Nitrite is added to several foodstuffs, as example bacon, as a preservative.According to the Swedish National Food Administration, sodium and potassium nitrite are permitted food additives (http://www.slv.se).