For decades sodium nitrite has been put to use in various industries such as food processing and textile, glass and even pharmaceutical. This chemical, which is white or slightly yellowish crystalline powder in its pure form, is water soluble and gets oxidized into sodium nitrate with the help of atmospheric oxygen. The immense popularity of
sodium nitrite as an industrial compound is mainly due to its great oxidizing properties as well as its ability to release nitrous acid in acidic solutions. Given below are some of the common industrial uses of this compound.
As a Food Additive
Over the years, sodium Nitrite has been invariably used by the processed food industry for preserving a variety of foods, especially fish and meat. The chemical not only helps in changing the color of the preserved fish and meat but also prevents the growth of many harmful bacteria. However, in the recent years, questions have been raised about the safety of this chemical as a food additive, mainly because of the toxic nature of the compound and if consumed in large amounts, it can prove fatal not only for animals, but humans as well.
In The Manufacture Of Dyes and Rubber Chemicals
Sodium nitrite is one of the most vital ingredients used for manufacturing rubber processing chemicals such as accelerators, retarders, anti-oxidants, and anti-ozonants. The chemical is also an integral part of the manufacturing process of azo dyes, mainly due to the fact that it is a convenient source of nitrous acid. Nitrous acid plays an important role in the nitrosation and diatozation of aromatic amines, which results in the production of the intermediate diamine salts. These salts then combine with amines, phenols, naphthols, and other compounds to form the azo dyes.
As A Corrosion Inhibitor
Sodium nitrite helps in preventing the corrosion of ferrous metals as it forms a firmly held layer of oxide over these metals. This prevents the dissolution of metal at the anodic areas. While it can prevent the corrosion of steel on its own, the compound may be used in combination with some other synergistic additives to ensure total protection against corrosion in case of mixed metal systems containing some percentage of various metals such as copper, brass, or aluminum. In the recent years the reduction in the use of carcinogenic hexavalent chromium-based corrosion inhibitors has also lead to an increased interest in the use of sodium nitrite as a corrosion inhibitor.
