E221 - Sodium sulphite

At a glance

• What it is: A white, water‑soluble salt of sulfur (also written “sodium sulfite”); E‑number E221.
• What it does: Helps prevent browning, keeps flavors and colors stable, and slows spoilage.
• Where it shows up: Dried fruits, dehydrated potatoes, some juices and concentrates, some seafood, wines and ciders.
• Any risks? Most people tolerate it, but a subset of individuals—particularly some asthmatics—can react to sulphites.
• Oversight: Evaluated by authorities and allowed within strict limits and with mandatory labeling in many regions.

Why is Sodium sulphite added to food?

Sodium sulphite acts mainly as an antioxidant and preservative. It scavenges oxygen and inhibits enzymes that drive browning, so foods keep their color and flavor longer. It also slows the growth of some spoilage microbes, extending shelf life.¹

What foods contain Sodium sulphite?

You’ll most often find sodium sulphite or other sulphites in:

• Dried fruit and vegetable products (to keep color)
• Dehydrated potatoes and baking mixes
• Juice concentrates and some soft drinks
• Wine and cider (labeled as “contains sulphites”)
• Some seafood, such as shrimp, to limit blackening
• Pickled and processed foods where color and freshness need protection

Food laws in the EU and many other regions set maximum permitted levels by food category rather than one single limit for all foods.²

What can replace Sodium sulphite?

Alternatives depend on the job you need done:

• For preserving and mold control: sorbic acid or potassium sorbate
• For general preservation: sodium benzoate in suitable products
• For antioxidant action and color protection: ascorbic acid or blends with citric acid
• For similar sulphite‑type functions: sulphur dioxide, sodium metabisulphite, or potassium metabisulphite

Every substitute has its own flavor, pH, and regulatory limits, so formulators choose case by case.

How is Sodium sulphite made?

Food‑grade sodium sulphite is typically produced by reacting a sodium alkali solution (such as sodium carbonate or sodium hydroxide) with sulphur dioxide gas, followed by purification and drying. The result is Na2SO3, usually appearing as white crystals or powder.³

Is Sodium sulphite safe to eat?

Authorities have evaluated the sulphites as a group (E220–E228). The European Food Safety Authority (EFSA) set a group acceptable daily intake (ADI) of 0.7 mg per kg body weight per day, expressed as sulphur dioxide equivalents (SO2).¹ In the EU, sulphites are authorised only in specified foods and at set maximum levels.²

Labeling rules help consumers identify sulphites. In the United States, sulphites must be declared on the label if present at 10 parts per million (ppm) or more in the finished food, including when carried over from processing.⁴ In the EU, “sulphur dioxide and sulphites” must be indicated as allergens when present at 10 mg/kg or 10 mg/L or more, expressed as SO2.⁵

Does Sodium sulphite have any benefits?

• Keeps foods looking and tasting fresh by slowing browning and oxidation.
• Helps retain color in products like dried fruit and shrimp.
• Reduces food waste by extending shelf life and stabilizing quality.

These benefits make sulphites popular in categories where color and flavor change quickly.

Who should avoid Sodium sulphite?

Most people can consume sulphites at permitted levels without problems. However, a subset of individuals—especially some with asthma—can experience sensitivity reactions to sulphites.¹ Those who know they are sensitive should check labels carefully. EU allergen labeling and U.S. labeling rules make it easier to identify when sulphites are present at significant levels.⁵⁴

Myths & facts

• Myth: “Sodium sulphite is banned.” Fact: It is allowed in many countries, but only in certain foods and within strict limits, with mandatory labeling where required.²
• Myth: “All reactions to wine are due to sulphites.” Fact: Only a minority of people are sulphite‑sensitive; reactions are most often respiratory in sensitive individuals. Many other components (like alcohol) can also cause symptoms.¹
• Myth: “Sulfites and sulfates are the same.” Fact: They are different chemical groups; a sulphite sensitivity does not imply a problem with sulfates.

Sodium sulphite in branded foods

On ingredient lists, look for “sodium sulphite,” “sodium sulfite,” “sulphites,” “sulfites,” or “E221.” Alcoholic drinks in many markets also carry a simple “contains sulphites” statement. If you’re sensitive, scan labels on dried fruits, dehydrated potatoes, seafood, juices, and wines, where sulphites are most common.

References

Footnotes

1. Re-evaluation of sulfur dioxide (E 220) and sulfites (E 221–228) as food additives — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/4438 ↩ ↩² ↩³ ↩⁴

2. Regulation (EC) No 1333/2008 on food additives (authorisation and use by category) — EUR-Lex. https://eur-lex.europa.eu/eli/reg/2008/1333/oj ↩ ↩² ↩³

3. Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008 — EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩

4. Food labeling; exemptions — 21 CFR 101.100 (U.S. eCFR). https://www.ecfr.gov/current/title-21/section-101.100 ↩ ↩²

5. Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex II (Allergens) — EUR-Lex. https://eur-lex.europa.eu/eli/reg/2011/1169/oj ↩ ↩²