Nitritsalze

Nitritsalze, or nitrite salts, are salts derived from nitrous acid (HNO2) that contain the nitrite anion NO2−. The most common examples are sodium nitrite (NaNO2), potassium nitrite (KNO2), and calcium nitrite (Ca(NO2)2). They are typically white or colorless crystalline solids that dissolve readily in water. In aqueous solution nitrite can act as a mild reducing agent and participates in nitrosation reactions under acidic conditions.

Production and occurrence: Industrial production of nitrite salts occurs by the partial reduction of nitrates in various processes, or as intermediates in chemical syntheses. In nature, nitrites arise from microbial activity in soils and water as part of the nitrogen cycle, where nitrates are reduced by bacteria. This makes nitrite presence common in soils, groundwater, and wastewater, often transient and dependent on environmental conditions.

Uses: The most widespread use of nitrite salts is as curing agents in meat processing, where sodium nitrite contributes to the characteristic pink color and helps inhibit certain bacteria. They are also employed in chemical synthesis as nitrosating agents, in laboratory settings, and in some industrial applications such as corrosion inhibition in cooling systems. Medically, nitrite salts have been used as antidotes for cyanide poisoning and in other limited therapeutic contexts.

Safety and regulation: Nitrite salts can be toxic at high doses and may cause methemoglobinemia, a condition affecting the blood’s oxygen-carrying capacity. They can form nitrosamines in the presence of certain amines and acids, compounds of concern for cancer risk. Accordingly, their use in foods is tightly regulated with country-specific limits, and safe handling requires avoiding contact with acids, proper storage, and protective measures to prevent unintended exposure. Environmental considerations include monitoring in water sources to prevent excessive nitrate-to-nitrite formation.