E250 Preservative

The main use of E250 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.

It is used in a variety of metallurgical applications, for phosphatizing and detinning.

E250 is an effective corrosion inhibitor and is used as an additive in industrial greases, as an aqueous solution in closed loop cooling systems, and in a molten state as a heat transfer medium.

Main article: E250 USE 

E250  is an efficient drug in case of cyanide poisoning. It is used together with sodium thiosulfate. It is on the World Health Organization's List of Essential Medicines.

Food additive and preservative

E250  is used to speed up the curing of meat and also impart an attractive pink color. E250 reacts with the meat myoglobin to cause color changes, first converting to nitrosomyoglobin (bright red), then, on heating, to nitrosohemochrome (a pink pigment).

The meat-packing industry has falsely claimed nitrite is used to prevent botulism (see also Inhibition of microbial growth). Several large meat processors produce processed meats without relying on E250.

Historically, salt has been used for the preservation of meat. The salt-preserved meatproduct was usually brownish-gray in color. When E250 is added with the salt, the meat develops a red, then pink color, which is associated with cured meats such as ham, bacon, hot dogs, and bologna. In the early 1900s, irregular curing was commonplace. This led to further research surrounding the use of E250 as an additive in food, standardizing the amount present in foods to minimize the amount needed while maximizing its food additive role. Through this research, E250 has been found to give taste and color to the meat; inhibit lipid oxidation that leads to rancidity; with varying degrees of effectiveness for controlling the growth of disease-causing microorganisms. The ability of E250 to address the above-mentioned issues has led to production of meat with extended storage life and has improved desirable color/taste. According to scientists working for the meat industry, E250 has improved food safety. However, this view is widely disputed in light of its ineffectiveness against botulism and the carcinogenic effects caused by adding E250 to meat.

Nitrite has the E number E250. Potassium nitrite (E249) is used in the same way. It is approved for usage in the EU,[15][16] USA[17] and Australia and New Zealand.