E221: Sodium Sulphite
Main role: preservation and oxidation control
Also listed as: sodium sulfite
What is E221 (Sodium Sulphite)?
Sodium sulphite E221 is a sulphite preservative used to limit microbial spoilage and unwanted oxidation. It is one member of the sulfur dioxide-sulphite family. The sulphite component is relevant when comparing it with E222 sodium hydrogen sulphite or E223 sodium metabisulphite.
What does it do in food?
Its main role is preservation and oxidation control. Preservation is one part of a food safety system. Recipe acidity, processing, packaging, and storage also affect how a product keeps. Follow the finished product’s storage instructions even when a preservative is listed.
Food and formulation examples
- Specified fruit preparations
- Potato processing
- Beverage preservation
These examples describe formulation roles, not a list of unrestricted legal uses. Availability and permitted applications differ by country and food category.
Label names and ingredient questions
Look for E221, E 221, or the ingredient name. Related names and label terms include sodium sulfite. A family code can cover more than one specified form; check the full declaration when the distinction matters.
Sodium sulphite is not sodium sulphate E514. Similar spelling hides different chemistry; people managing sulphite sensitivity should look for the sulphite family rather than all sulfur-containing ingredients.
Is E221 safe?
EFSA’s 2022 review identified concerns for high consumers and withdrew the temporary group intake limit. EFSA sulphites follow-up (2022).
A label identifies the ingredient but usually not its concentration. Calculating daily intake requires the amount in the food and the quantities eaten.
Authorization and conditions of use
The Great Britain food additive register lists E221 as Sodium sulphite. This is an entry subject to its stated conditions, not unrestricted permission for every food. The record links to the applicable authorization terms. For an EU product, use the European Commission food additive database to check the relevant food category and limits. Other countries may use different names or rules.