Abstract

Sodium nitrite, NaNO₂, is a versatile industrial chemical having applications that are widely based on its oxidizing properties or its ability to yield nitrous acid on acidification. It is hygroscopic and quite soluble in water, but not in most organic solvents. Sodium nitrite is a moderately strong oxidizer and toxic by ingestion. It can react violently with some chemicals, evolves toxic NO_x on decomposition, and can promote burning when exposed to fire. It may be derived from the reduction of sodium nitrate, but is typically manufactured by the absorption of nitrogen oxides into solutions of sodium hydroxide or sodium carbonate. Dry and liquid forms of the product in several grades are offered in bulk and a variety of packaging options. Dry products may be treated with an anticake. Typical assays are 99% NaNO₂ for dry and 42% NaNO₂ for liquid products. Sodium nitrite consumed domestically is primarily of U.S. origin, with some imports. The product is used in azo dyes, rubber chemicals, heat treating and heat-transfer salts, meat curing, metal finishing, organic chemical syntheses, and as a corrosion inhibitor.