E224 · Potassium metabisulfite
- WHO
- Safe
- FDA
- Safe
- EFSA
- Safe
- FSANZ
- Safe
- Japan
- Safe
- UK FSA
- Safe
- Health Canada
- Safe
What is E224?
Potassium metabisulfite (chemical formula K2S2O5) is a sulfite preservative and antioxidant widely used in winemaking, beer, and dried fruit to block oxidation and unwanted microbial growth. It releases sulfur dioxide (SO2), the active preservative gas shared by all sulfite additives. Food-grade use is approved by the FDA and EFSA within set limits. As with other sulfites, sensitive individuals — especially some people with asthma — may experience allergic-type reactions.
Also appears on labels as: Potassium metabisulfite, Potassium pyrosulfite, K2S2O5, E224, E 224, E-224, Food preservative potassium metabisulfite, Potassium disulfite, Metabisulfite of potassium, Potassium pyrosulphite, Preservative E224, INS 224.
What the evidence says
- Can trigger reactions (flushing, hives, wheezing, or in rare severe cases anaphylactoid symptoms) in sulfite-sensitive individuals, especially some people with asthma.
- EU/EFSA and FDA require allergen labelling when total sulfur dioxide residues are 10 mg/kg or more.
Frequently asked questions
Is E224 safe?
Our overall verdict for E224 (Potassium metabisulfite) is “Safe”, based on the most cautious of the major regulators’ positions — FDA: safe; WHO: safe; EFSA: safe; FSANZ: safe; Japan: safe; UK FSA: safe; Health Canada: safe.
Is E224 vegan, halal or gluten-free?
According to our ingredient data for Potassium metabisulfite — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E224 and why is it used?
Potassium metabisulfite (chemical formula K2S2O5) is a sulfite preservative and antioxidant widely used in winemaking, beer, and dried fruit to block oxidation and unwanted microbial growth. It releases sulfur dioxide (SO2), the active preservative gas shared by all sulfite additives. Food-grade use is approved by the FDA and EFSA within set limits. As with other sulfites, sensitive individuals — especially some people with asthma — may experience allergic-type reactions.
Does E224 contain allergens?
No known allergens are recorded for Potassium metabisulfite, though some people report sensitivity (sulfites).
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This page summarises publicly available regulatory assessments and research. It is general information, not medical advice. Sources: EFSA, FDA, WHO and the studies linked above.