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E221 Sodium sulfite

E221PreservativesOrigin: Lab-made
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The short answer
Sodium sulfite (E221) is a sulfite that keeps dried fruit bright and slows browning in shrimp. It's safe for most people, but it can trigger asthma-like symptoms in the small share who are sulfite-sensitive.
Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberE221
Comes fromLab-made
What it doesPreservatives
Glycemic index—
Daily limit0.7 mg/kg
Also calledE221, Sodium sulphite

Rules by country

🇺🇸 US FDAWarning label required
🇪🇺 European UnionWarning label required
🇨🇦 Health CanadaWarning label required
CaliforniaNo extra rules

Sulfites must be declared on the label in the US and Canada at 10 ppm or more, and in the EU at 10 mg/kg or more. It is allowed in dried fruit, frozen shrimp, wine and some sauces, within set limits.

How much is too much? (Acceptable Daily Intake)

49 mgper day is the safe upper limit

Based on 0.7 mg per kg of body weight (EFSA / JECFA). A 20 kg (44 lb) child: 14 mg a day.

What is it?

Sodium sulfite is a salt of sulfurous acid. When it meets the acids in food, it releases sulfur dioxide, which blocks browning and slows the growth of microbes. It is closely related to sulfur dioxide (E220), which is the form that does the work once the salt dissolves.

Where it comes from: Made by treating sodium carbonate or sodium hydroxide with sulfur dioxide. It is a white powder that releases sulfur dioxide when it meets acid or moisture in food.

Why it’s in food

  • Keeps dried apricots and raisins bright orange
  • Stops shrimp from turning black on ice
  • Slows browning in cut produce
  • Helps preserve wine and cider

Often found in

Dried fruitFrozen shrimpWineMolassesDehydrated potatoesSauces

Also listed as: E221, Sodium sulphite

Health & gut impact

AsthmaConcern

Sulfites can cause wheezing or breathing trouble in some people with asthma, mostly those who are sensitive to them. Most people with asthma eat sulfited foods without trouble.

FDA guidance on sulfite labeling

Daily limitConcern

The international group limit for sulfites is 0.7 mg per kg of body weight a day, counted as sulfur dioxide. Typical food use stays well below it.

JECFA evaluation of sulfites

What can I use instead?

Ascorbic acid

Ratio: Not 1:1; works only as an antioxidant

Best for: Cut fruit and potatoes without a sulfur taste

Lemon juice

Ratio: Varies by batch

Best for: Home-cut apples and pears

Related

More preservatives:

Benzoic acid E210Benzoic acid (E210) is the parent of sodium benzoate. It keeps acidic foods from molding. It is allowed within a daily limit, and in soft drinks with vitamin C it can form a little benzene.Use in moderationCalcium disodium EDTA (EDTA) E385Calcium disodium EDTA (E385) grabs stray metals so dressings, sodas and canned beans keep their color and flavor. Very little is absorbed, and it's safe in the small amounts allowed.Use in moderationCalcium Propionate E282Calcium propionate (E282) is the mold inhibitor in most packaged bread. It's considered safe, vegan and gluten-free, though a few small studies have raised questions about behavior in children and blood sugar.Use in moderationCalcium sorbate E203Calcium sorbate (E203) is a salt of sorbic acid that stops mold and yeast from growing in bread, cheese and wine. It's a synthetic, vegan and gluten-free preservative with a long safety record.Generally safe

Common questions

Is sodium sulfite safe?

For most people, yes. It is approved in the US, EU and Canada within set limits, and the main risk is a reaction in the small group who are sulfite-sensitive.

Does sodium sulfite have to be on the label?

Yes, when the level is high enough. The US and Canada require it at 10 ppm or more, and the EU sets a similar threshold.

Is Sodium sulfite safe?

Use in moderation (51/100). Sulfites must be declared on the label in the US and Canada at 10 ppm or more, and in the EU at 10 mg/kg or more. It is allowed in dried fruit, frozen shrimp, wine and some sauces, within set limits.

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Scientific sources & regulatory citations
  • EFSA OpenFoodTox: E221
  • FDA guidance on sulfite labeling
  • JECFA evaluation of sulfites

INS 221 · CAS 7757-83-7