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E220PreservativeElevated concern
Sulphur Dioxide
In plain words
The short version
Free sulphur dioxide — the active species in all sulfite preservation and a major label allergen.
Why we flag it
A preservative and antioxidant (sulphur dioxide). It works well, but sulfites can trigger breathing problems in people with asthma and reactions in other sensitive people, so labels must declare them. That sensitivity risk is why we flag it.
Safety profile
ADI of 0.7 mg/kg body weight (combined sulfites, expressed as SO2). A documented allergen — triggers severe asthma in an estimated 5–10% of asthmatics and rare anaphylaxis. Mandatory allergen labelling above 10 mg/kg in the EU, US, and most jurisdictions. Destroys dietary thiamine (vitamin B1).
The detail
Educational information only. Not medical or dietary advice.