Sodium nitrite

Sodium nitrite (CAS 7632-00-0), also recognized in food labeling as E250, is an inorganic salt used industrially as a curing agent, preservative, and color fixative.

Where is Sodium nitrite used?

• Meat processing: active curing agent in bacon, ham, hot dogs, and deli meats, inhibiting Clostridium botulinum growth while fixing myoglobin
• Pharmaceuticals: intermediate and active ingredient in certain antidote formulations
• Food production: antioxidant to retard rancidity and extend shelf life in cured and preserved products
• Industrial: corrosion inhibitor in metalworking fluids and heat transfer systems
• It controls microbial growth and stabilizes the characteristic pink color in processed meat products.
• It is used as a corrosion inhibitor in cooling systems and boilers where water treatment is essential.
• In the synthetic dye industry it is used as a reagent for diazotization reactions to produce azo dyes and organic pigments.
• It is blended with sodium nitrate and potassium nitrate to form a low-melting eutectic molten salt for high-temperature heat transfer and thermal energy storage.

Formulation notes

• Reacts with amines to form nitrosamines, a reaction that is carefully controlled in food processing, especially meat curing.
• Decomposes on contact with acids, releasing toxic nitrogen oxide fumes.
• No replacement solution for nitrite additives (vegetable broth formulations, lactic ferments with yeast extracts, polyphenol- and vitamin C-rich formulations) manages the microbiological risk, the carcinogenic risk linked to lipid peroxidation and the maintenance of organoleptic characteristics simultaneously.

Typical specification

• Industrial standard grade has a primary purity (NaNO2 dry basis) of at least 99.0%.
• Industrial standard grade limits sodium nitrate impurity to 0.8% or less.
• Industrial standard grade has a moisture content of 1.5% or less.

Regulatory status

• Classified under UN transport hazard class 5.1 (oxidizing substances), with subsidiary risk 6.1 (toxic) and packing group III.
• Before the French action plan of 27 March 2023, the maximum permitted incorporation dose of nitrites in France was 20% lower than the level set by EU regulation, e.g. 120 ppm for cooked ham in France versus 150 ppm at EU level.
• Carries hazard statement H272: may intensify fire; oxidizer.
• Classified as an oxidizer that may intensify fire under the harmonized CLP classification.

Storage, packaging and handling

• At room temperature it reacts with ammonium salts, amides and mixtures containing them; the reaction can be violently explosive and followed by ignition.
• Dust dispersion should be prevented during handling.

Frequently asked questions about Sodium nitrite

What is the environmental hazard classification of sodium nitrite under CLP?

Sodium nitrite is classified as very toxic to aquatic life under the harmonized CLP classification.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.