E251: Sodium nitrate

What is E251?

Sodium nitrate (E251) is a crystalline salt of sodium and nitric acid. In food it acts largely as a reservoir: bacteria gradually convert it into nitrite, which is the active curing agent.

Origin and production

It is produced synthetically or purified from natural mineral deposits, historically known as Chile saltpetre. Nitrates also occur naturally in vegetables such as spinach, beetroot and lettuce.

Why is it used?

It is used in slow-cured meats such as some hams, salamis and sausages to protect against harmful bacteria, including those causing botulism, and to develop the characteristic pink colour and flavour. In some cheeses, such as Gouda, it prevents spoilage by gas-producing bacteria.

Vegan, vegetarian and halal

Sodium nitrate itself is mineral-derived and suitable for vegans and vegetarians, though it is mainly used in meat and cheese products.

Safety and regulation

Nitrates are authorised in the EU with strict maximum levels and were re-evaluated by EFSA, which identified a risk of exceeding the acceptable daily intake for some population groups. Limits also aim to reduce the formation of nitrosamines in cured meats.

Common in