Used as a food preservative, especially in cured meats like bacon, ham, and sausages, to prevent bacterial growth, including Clostridium botulinum, which causes botulism. It helps maintain the pink or red color of meat by reacting with myoglobin.

Also used in industrial settings as a corrosion inhibitor in cooling systems and in the production of dyes, pharmaceuticals, and nitrosamine compounds.

In medicine, it is part of a treatment for cyanide poisoning, where it helps convert hemoglobin to methemoglobin, which binds cyanide and reduces its toxicity.