E222: Sodium bisulphite

What is E222?

Sodium bisulphite (E222), also called sodium hydrogen sulphite, is a sulphite compound usually supplied in solution. In food it releases sulphur dioxide, which gives it preservative and antioxidant properties.

Origin and production

It is produced synthetically by passing sulphur dioxide through a solution of sodium carbonate or sodium hydroxide.

Why is it used?

It prevents browning and microbial spoilage. In seafood such as prawns and shrimp it is used to prevent black spots forming on the shell, and it is also used in some processed vegetable mixes, prepared meals, dried fruits and wine.

Vegan, vegetarian and halal

Sodium bisulphite is a synthetic mineral compound and suitable for vegans and vegetarians, although it is often used in seafood products.

Safety and regulation

Sulphites are authorised in the EU with maximum levels and must be declared as an allergen above 10 mg per kg or litre, as they can cause reactions in some sensitive people. EFSA identified a risk of exceeding the acceptable daily intake for some population groups.

Common in