Preservatives
Sulfites
Definition
What it is
Sulfite preservative: can trigger asthma attacks and allergic reactions in sensitive individuals; mandated allergen declaration in the US, EU, and Canada above 10ppm.
On the label
Label names covered by this flag
- sulfites
- sulphur dioxide
- sulfur dioxide
- sodium metabisulfite
- potassium metabisulfite
- sodium bisulfite
- potassium bisulfite
- sodium sulfite
- potassium sulfite
- calcium sulfite
- e220
- e221
- e222
- e223
- e224
- e225
- e226
Regulation
Regulatory status
- Australia/NZ Allergen declaration required
- Canada Allergen declaration required
- European Union Allergen declaration required
- United States Allergen declaration required
Explainer
In plain language
Sulfites are a family of sulfur-based preservatives used to stop browning, control microbes, and extend shelf life. They cover sulfur dioxide gas and several salts like sodium metabisulfite and potassium bisulfite. They occur naturally in small amounts during fermentation, which is why wine contains them, and they are also added directly to dried fruit, processed potatoes, and many other foods.
Assessment
Why it is flagged
The main established concern is sensitivity rather than general toxicity. Sulfites can trigger asthma attacks and allergic-type reactions in sensitive people, particularly those with asthma, and this effect is well documented. Because of that, the FDA requires sulfites to be declared on labels when present at 10 parts per million or more, and the EU and Canada have similar declaration rules. The FDA also banned sulfites on fresh fruits and vegetables meant to be eaten raw, such as salad bar produce, in 1986 after adverse reactions. For most people without sulfite sensitivity, normal dietary amounts are not associated with harm, so Clear Label flags them mainly so sensitive users can spot them and test their own reactions in their logs.
In the aisle
Where it commonly shows up
- Wine, beer, and hard cider
- Dried fruit like apricots and raisins
- Processed and dehydrated potatoes
- Bottled lemon and lime juice
- Pickled vegetables and some condiments
- Shrimp and other preserved seafood
- Molasses and some dried vegetables
Practical
Reading the label
US labels may list a specific salt like sodium metabisulfite, or a general phrase such as 'contains sulfites.' In the EU they appear as E220 through E228. Golden-colored dried fruit and light-colored dried potatoes are common places to meet them, and wine labels in many markets carry a sulfite declaration.
Alternatives
If you want to avoid it
Some people choose unsulfured dried fruit, which is usually darker in color, or fresh fruit instead. Naturally low-sulfite or 'no added sulfite' wines exist, though all wine contains some from fermentation.
FAQ
Common questions
Why does wine list sulfites?
Some sulfites form naturally during fermentation, and many winemakers add more as a preservative. Labels in the US, EU, and Canada must declare sulfites above the regulatory threshold, which is why the notice appears even on wines with only added preservative levels.
Are sulfites the same as MSG or nitrates?
No. Sulfites are a distinct group of sulfur-based preservatives. MSG is a flavor enhancer and nitrates are curing agents, all tracked separately by Clear Label.
Who reacts to sulfites?
Reactions are most documented in people with asthma, who may experience wheezing or other symptoms. Most people without sulfite sensitivity tolerate normal dietary amounts, so this is a pattern sensitive users can test in their own logs.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.