E222 - Sodium bisulphite

At a glance

• What it is: Sodium bisulphite (also spelled bisulfite) is the sodium salt of the bisulfite ion; food-grade E-number E222. It works mainly as an antioxidant and preservative.
• Why it’s used: To slow enzymatic browning and oxidation, and to help control certain microbes in foods and beverages.
• Where you’ll see it: Common in wine, dried fruits, bottled lemon/lime juice, pickled foods, some shrimp and potato products.
• Regulations: In the U.S., sulfites must be declared on labels when present at 10 ppm or more. “ppm” means parts per million.
• Sensitivities: A subset of people, particularly some with asthma, can be sensitive to sulfites.
• Related additives: Other approved sulfiting agents include sulphur dioxide, sodium sulphite, sodium metabisulphite, and potassium metabisulphite.

Why is Sodium bisulphite added to food?

Manufacturers add E222 because it protects color and flavor. As an antioxidant, it reacts with oxygen and certain browning intermediates, slowing enzymatic browning in cut fruit and potatoes and protecting aroma compounds in wine. It also has preservative action that helps control unwanted microbes in some foods and drinks.¹

What foods contain Sodium bisulphite?

You’ll most often find sodium bisulphite and other sulfites in:

• Wine and some ciders
• Dried fruits (for example, apricots and raisins)
• Bottled lemon or lime juice
• Some shrimp and pickled foods These are common examples of where sulfites are used or may be present.²

What can replace Sodium bisulphite?

Alternatives depend on the food and the goal:

• To limit browning: ascorbic acid, citric acid, good packaging, or lowering pH.
• To provide antioxidant protection: sodium ascorbate, extracts of rosemary, or tertiary butylhydroquinone (TBHQ) where allowed.
• To preserve: sorbic acid, potassium sorbate, or sodium benzoate in suitable products.
• To limit oxygen: Packaging with nitrogen or carbon dioxide.

How is Sodium bisulphite made?

Commercially, sodium bisulphite is typically produced by absorbing sulfur dioxide gas (SO2) into an aqueous solution of sodium hydroxide or sodium carbonate, forming NaHSO3 in solution.³ Concentration and handling conditions are controlled to keep it in the bisulphite form rather than converting to metabisulphite.

Is Sodium bisulphite safe to eat?

Regulators evaluate sulfites as a group. The European Food Safety Authority (EFSA) established a group acceptable daily intake (ADI) of 0.7 mg per kilogram of body weight per day, expressed as sulfur dioxide equivalents. “ADI” is the amount considered safe to consume daily over a lifetime; “mg/kg” means milligrams per kilogram of body weight.¹ In the U.S., sulfiting agents must be declared on food labels when present at 10 ppm (parts per million) or more in the finished food.⁴ For wine sold in the U.S., a separate rule requires the statement “Contains sulfites” when the sulfite level is 10 ppm or higher.⁵

Most people can consume foods with E222 within regulatory limits without problems. However, a subset of individuals is sensitive to sulfites and may experience symptoms such as wheezing or hives; see “Who should avoid” below for details.²

Does Sodium bisulphite have any benefits?

For food quality, E222 helps:

• Maintain color by slowing enzymatic browning in cut fruit and potatoes
• Protect flavor and aroma by limiting oxidation in beverages like wine
• Extend shelf life by helping control certain spoilage processes These are the main reasons it is used in modern food processing and winemaking.

Who should avoid Sodium bisulphite?

• People with sulfite sensitivity: Some individuals, including a portion of people with asthma, can react to sulfites in foods and beverages. If sulfites are a known trigger, your clinician may advise strict avoidance and careful label reading.²
• People with sulfite oxidase deficiency: This very rare genetic condition impairs the body’s ability to process sulfites; medical teams typically recommend avoiding sulfite-containing foods.⁶
• Anyone advised by a healthcare professional to avoid sulfites for medical reasons.

Myths & facts

• Myth: “Sulfites cause reactions in everyone.” Fact: Most people tolerate sulfites; sensitivity affects a subset of individuals.
• Myth: “Bisulphite and bisulfite are different.” Fact: They are two spellings for the same compound.
• Fact: Sodium bisulphite is part of the approved sulfiting agents group (E220–E228). Labels help you spot them; in the U.S., declaration is required at 10 ppm or more in the finished food.⁴

Sodium bisulphite in branded foods

On ingredient lists, look for “sodium bisulphite” or “sodium bisulfite.” You may also see a separate “Contains sulfites” statement on certain products. Wine labels in the U.S. must state “Contains sulfites” when levels are 10 ppm or higher.⁵ If you manage a sensitivity, check both the ingredients and any allergen or “contains” statements, and contact the manufacturer if uncertain.

References

Footnotes

1. Re‑evaluation of sulphites (E 220–228) as food additives — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/4438 ↩ ↩²

2. Asthma: Common triggers (includes sulfites in foods and beverages) — U.S. CDC. https://www.cdc.gov/asthma/triggers.html ↩ ↩² ↩³

3. Sodium bisulfite — PubChem (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-bisulfite ↩

4. 21 CFR 101.100(a)(4): Exemptions from food labeling; sulfiting agents at 10 ppm or more must be declared — U.S. FDA (eCFR). https://www.ecfr.gov/current/title-21/part-101/section-101.100 ↩ ↩²

5. 27 CFR 4.32(e): Declaration of sulfites on wine labels (≥10 ppm) — U.S. TTB (eCFR). https://www.ecfr.gov/current/title-27/part-4/section-4.32 ↩ ↩²

6. Sulfite oxidase deficiency — Genetic and Rare Diseases Information Center (NIH). https://rarediseases.info.nih.gov/diseases/10944/sulfite-oxidase-deficiency ↩