Sulfur dioxide

Sulphur dioxide and sulphites (E220–E228) are authorised food preservatives in the EU and UK, so they have passed regulatory safety assessment. However, in its 2022 follow-up EFSA could not confirm their safety at current use levels and withdrew the previous acceptable daily intake, noting the margin of exposure raises some concern for high consumers. For most people at normal intakes they are treated as low-risk, but the science is still under review. This is general information, not medical advice.

Sulphites are used mainly for their preservative and antioxidant effect: they suppress microbial growth, prevent browning and help retain colour. That is why they are common in wine and beer, dried fruits such as raisins and apricots, and some processed meats and preserved vegetables. On labels they appear as E220–E228 or by name (e.g. “preservative: sulphur dioxide”).

Yes. Sulphites can cause reactions in some people, particularly those who are asthmatic, which is why they are one of the substances that must be declared on EU and UK labels. These reactions are usually an intolerance or sensitivity rather than a true allergy, but for sensitive individuals the physical product label is the authoritative guide, and severe reactions should be discussed with a doctor.

Yes. Under EU Regulation (EU) No 1169/2011 (Annex II) and equivalent UK law, “sulphur dioxide and sulphites” must be declared whenever present at more than 10 mg/kg or 10 mg/litre, expressed as SO₂. It is the only listed allergen with a numeric threshold, and the declaration is required even on products like wine that do not otherwise carry a full ingredient list (e.g. “contains sulphites”).

Typical sources include wine and beer, dried fruits (raisins, apricots, sultanas), some dried or processed potato products, certain processed meats such as sausages, and preserved vegetables, vinegars and fruit juices. They are listed as E220–E228 or by name. If you are sulphite-sensitive, always check the ingredient list, since amounts above 10 mg/kg or 10 mg/L must be declared.

EFSA set a temporary group ADI of 0.7 mg SO₂ equivalents per kg body weight in its 2016 re-evaluation, but in its 2022 follow-up it withdrew this ADI because adequate toxicity data were still not available and no new studies were submitted. EFSA now applies a margin-of-exposure approach and flagged possible concern for high consumers of sulphite-containing foods. This reflects regulatory status only and is not medical advice.

Yes — it contains no animal-derived material. It is an inorganic gas produced industrially. The same applies to a vegetarian diet.

Yes — the additive itself contains no gluten. A gluten-free claim belongs to the finished product, though — check the pack, not the additive.

It is an inorganic gas produced industrially and contains no animal-derived material, so the additive itself is not inherently non-halal. Certification applies to a finished product rather than to an additive, so a halal certification mark on the pack is the authoritative signal.

Sulfur dioxide is an EU-declarable allergen above 10 mg/kg precisely because it causes reactions: it can trigger asthma symptoms, wheezing and headaches in sulfite-sensitive people, and asthmatics are the group most often affected. For everyone else EFSA has set an acceptable daily intake, though its 2016 re-evaluation noted that the available data were limited.