Sulphur Dioxide and Sulphites (E220–E228)
Sulphur dioxide and sulphites are long-established, widely used preservatives that stop foods from browning and spoiling. For most people they cause no problems at permitted levels; however, because they can trigger serious reactions such as shortness of breath in some people with asthma, they must be declared as an allergen on the label at levels above 10 mg/kg.
Risk range
1 is the lowest and 10 the highest risk. The range depends on the amount used, whether the product is rinsed off and how it is used. The Temiz İçerik app uses the same ranges.
The range is moderate to high because, although sulphites are low risk for the general population, they can cause sudden and serious reactions in sensitive people with asthma; the upper end reflects high-sulphite products such as dried fruit and wine.
What are sulphites and what do they do?
This group includes sulphur dioxide (E220) and the salts derived from it: sodium sulphite (E221), sodium bisulphite (E222), sodium metabisulphite (E223), potassium metabisulphite (E224), calcium sulphite (E226), calcium bisulphite (E227) and potassium bisulphite (E228). All of them release the same active agent in food, sulphur dioxide.
Sulphites have two main jobs: slowing the growth of microorganisms and preventing the enzymatic browning of fruit and vegetables. They have also been used for centuries in winemaking to suppress unwanted yeasts and bacteria and to prevent oxidation.
Which products contain them?
- Dried apricots, raisins and other dried fruit (bright orange apricots are usually sulphured)
- Wine, beer and some alcoholic drinks
- Fruit juices and concentrates, bottled lemon juice
- Pickles, vinegar, some sauces and mustard
- Frozen or dried potato products, some seafood (for example prawns)
A common example in Türkiye is dried apricots: sulphured apricots keep their light orange colour, while unsulphured, sun-dried apricots turn brown. The difference in colour is a difference in processing, not in quality.
Are they harmful? The scientific assessment
In the body, sulphites are converted into harmless sulphate by the enzyme sulphite oxidase; that is why most people have no problems at permitted levels. Nevertheless, in its 2022 follow-up assessment EFSA withdrew the temporary acceptable daily intake it had previously set, because of insufficient toxicity data, and pointed out that there may be a health concern at high intakes.
The really important issue is sensitivity. In some people with asthma, a food or drink containing sulphites can trigger wheezing, coughing and shortness of breath. Although these reactions do not arise through the immune system like a classic allergy, they can be serious. For this reason, in the EU and in the Turkish Food Codex aligned with it, sulphites at more than 10 mg/kg or 10 mg/L expressed as sulphur dioxide are on the list of mandatory allergens, alongside gluten and peanuts, and must be emphasised on the label.
Sulphites also react with vitamin B1 (thiamine) and break it down. For this reason their use is restricted in foods that are a source of thiamine.
Who should be careful?
- People with asthma: Those who experience breathing problems especially after wine, dried fruit or drinks containing sulphites should tell their doctor.
- People diagnosed with sulphite sensitivity: It is important to check labels for “sulphur dioxide and sulphites” and to ask in restaurants.
- People who often snack on dried fruit: Unsulphured options are available and offer the same nutritional value.
What to do when you see them on a label
If you have no sensitivity, occasionally eating a product containing sulphites is usually not a problem. If you have asthma and experience symptoms after certain foods, it is helpful to choose unsulphured dried fruit and read the labels of drinks such as wine. Washing dried fruit or soaking it briefly in water before eating can reduce some of the sulphite on the surface.
Frequently asked questions
How can I tell unsulphured apricots?
Unsulphured dried apricots are usually dark brown. For packaged products, you can check the ingredient list for sulphur dioxide or E220–E228.
What does the “contains sulphites” warning on wine mean?
It shows that the wine contains more than 10 mg/L of sulphur dioxide. It is an allergen declaration intended to warn people who are sensitive to sulphites.
Is sulphite allergy a real allergy?
Most reactions do not arise through the classic allergy mechanism; that is why they are called a “sensitivity” or “intolerance”. However, because they can be serious in people with asthma, sulphites are legally labelled like allergens.
Sources
Updated: 2026-10-11 · How we score
This page is for general information and is not personal medical advice. Warnings on the product label and the advice of a health professional always come first.