Sodium Nitrite
What it does
Cures meats (bacon, ham).
How it's made
Synthesised nitrite salt.
Sodium nitrite is the main curing agent for preserved meats such as bacon, ham, salami and hot dogs. It prevents the growth of the bacteria that cause botulism and other food poisoning, and it develops the pink colour and distinctive cured flavour these products are known for.
It is made industrially by absorbing nitrogen oxide gases into a sodium base such as sodium hydroxide or sodium carbonate, or by reducing sodium nitrate. Both routes produce sodium nitrite, which is then purified and crystallised.
Because pure sodium nitrite is powerful and toxic in large amounts, it is supplied to meat processors already blended into ordinary salt as "curing salt" to make it safe to handle and dose. Its use is strictly limited by regulation to the lowest level that ensures safety against botulism, balancing its essential protective role against concern over the nitrosamine compounds nitrites can form.
Possible reactions
Nitrosamine formation concern; headaches in some; linked to bowel-cancer risk with processed meat.