SODIUM NITRITE

The main use of sodium nitrite is for the industrial production of organonitrogen compounds. It is a reagent for conversion of¿¿amines¿¿into¿¿diazo¿¿compounds, which are key precursors to many dyes, such as¿¿diazo dyes.¿¿Nitroso compounds¿¿are produced from nitrites. These are used in the rubber industry.^[5]

Other applications include uses in¿¿photography. It may also be used as anelectrolyte¿¿in¿¿electrochemical grinding¿¿manufacturing processes, typically diluted to about 10% concentration in water. It is used in a variety of metallurgical applications, for phosphatizing and detinning.

Sodium nitrite is an effective¿¿corrosion inhibitor¿¿and is used as an additive in industrial greases,^[6]¿¿as an aqueous solution in closed loop cooling systems, and in a molten state as a heat transfer medium.^[7]

Sodium nitrite is used togetherwith¿¿sodiuthiosulfate¿¿totreat¿¿cyanidepoisoning.^[8]It is in the section "antidotes and other substances used in poisonings" of theWorld Health Organization's List of Essential Medicines, the most important medications needed in a basic¿¿health system.^[2]¿¿
n the early 1900s, irregular¿¿curing¿¿was commonplace. This led to further research surrounding the use of sodium nitrite as an¿¿additive¿¿in¿¿food, standardizing the amount present in foods to minimize the amount needed while maximizing its¿¿food additive¿¿role.^[9]¿¿Through this research, sodium nitrite has been found to inhibit growth of disease-causing¿¿microorganisms; give taste and color to the meat; and inhibit lipid oxidation that leads to rancidity.^[9]¿¿The ability of sodium nitrite to address the above-mentioned issues has led to production of¿¿meat¿¿with improved¿¿food safety, extended storage life and improving desirable color/taste.^[9]¿¿It has the¿¿E number¿¿E250.¿¿Potassium nitrite(E249) is used in the same way. It is approved for usage in the¿¿EU,^[10][11]USA^[12]¿¿and Australia and New Zealand.^[13]
Sodium nitrite is well known for its role in inhibiting the growth of¿¿Clostridium botulinum¿¿spores in refrigerated meats.^[14]¿¿The mechanism for this activity results from the inhibition of¿¿iron-sulfur clusters¿¿essential to energy metabolism of¿¿Clostridium botulinum.^[14]¿¿However, sodium nitrite has had varying degrees of effectiveness for controlling growth of other spoilage or disease causingmicroorganisms.^[9]¿¿Even though the inhibitory mechanisms for sodium nitrite are not well known, its effectiveness depends on several factors including residual nitrite level,¿¿pH, salt concentration, reductants present and¿¿ironcontent.^[15]¿¿Furthermore, the type of¿¿bacteria¿¿also affects sodium nitrites effectiveness.^[15]¿¿It is generally agreed upon that sodium nitrite is not considered effective for controlling¿¿gram-negative¿¿enteric pathogens such asSalmonella¿¿and¿¿Escherichia coli.^[15]