Introduction
  Sodium nitrite (NaNO2), which is combined to generate the nitrite ion and sodium ion of inorganic salt. Sodium nitrite is easy to be delirized and soluble in water and liquid ammonia. Its aqueous solution is alkaline and slightly soluble in organic solvents such as ethanol, methanol and diethyl ether. Sodium nitrite has a salty taste and is sometimes used to make fake salt. Sodium nitrite reacts with oxygen to form sodium nitrate when exposed to air. If it is heated to above 320ºC, it will decompose and produce oxygen, nitrogen oxide and sodium oxide. Combustible and explode easily in contact with organic matter.
 


 
Physical properties
  White to light yellow granule, stick or powder. It's hygroscopic. Soluble in 1.5 parts cold water, 0.6 parts boiling water, slightly soluble in ethanol. Relative density 2.17. Melting point is 271 ºC.

Chemical properties
  Its water solution is alkaline, is a strong oxidant and has reductive property, will gradually oxidize in the air, the surface will become sodium nitrate, heating to 320ºC above decomposition, can also be oxidized by oxidants; Brown nitrogen dioxide gas is released by decomposition with weak acid. Contact with organic matter and reducing agent can cause explosion or combustion, and emit toxic and irritating nitrous oxide gas; In case of strong oxidant can also be oxidized, especially ammonium salt, such as ammonium nitrate, ammonium persulfate and so on at room temperature, that is, can interact to produce high heat, causing combustible combustion. 



application
  Chromatographic analysis. Drip analysis was used to determine mercury, potassium, and chlorate. Diazo reagent. Nitrous reagent. Soil analysis. Serum bilirubin was measured in liver function test.
  Bleach for silk and linen, metal heat treating agent; Steel corrosion inhibitor; Antidotes for cyanide poisoning, laboratory component
  Analytical reagent, used as hair color agent, microbiological agent, preservative in meat products processing. It has applications in bleaching, electroplating and metal treatment and is called industrial salt.

Health concerns

cancer
  Too much sodium nitrite can cause cancer. Nitrite sodium in cooking and digestion process and food amine reaction, carcinogen nitrosamines compounds. Nitrosamines are also found in traditional foods, such as cured meat and dried salted fish. In the 1820s, a major improvement in meat pickling in the United States reduced the use of nitrites by 69 percent, resulting in a dramatic drop in the death rate of gastric cancer patients. Around 1970, it was found that ascorbic acid (vitamin C) effectively inhibited the production of nitrosamines. This has led the United States to require meat products to contain at least 550ppm of ascorbic acid. Manufacturers sometimes use the cheaper but equally effective isoascorbic acid as an alternative. Manufacturers also add alpha-tocopherol (vitamin E) for further effect. The three compounds above all inhibit the production of nitrosamines by their antioxidant properties. Taking ascorbic acid as an example, it can reduce the converted nitrite anhydride of sodium nitrite to nitric oxide by REDOX action, and is oxidized to dehydroascorbic acid itself.
  This preservative is found in luncheon meats, cured meats and fish. Can lead to many types of cancer.