E227 - Calcium bisulphite

At a glance

• What it is: A sulphite salt used mainly as a preservative and antioxidant.
• What it does: Helps prevent browning and spoilage in foods and beverages.
• Where it shows up: Allowed in limited categories such as some wines, dried fruits, and processed foods, depending on local rules.
• Safety notes: Most people tolerate sulphites, but a small proportion—especially some people with asthma—can be sensitive.
• On the label: May be listed by name (calcium bisulphite/bisulfite, E227) or as “sulphites,” often with a statement when amounts exceed a set threshold.

Why is Calcium bisulphite added to food?

Food makers use calcium bisulphite to preserve color and freshness. As part of the sulphur dioxide/sulphites group (E220–E228), it works by slowing oxidation (browning) and reducing the growth of certain microbes that can spoil food.¹

What foods contain Calcium bisulphite?

You’re most likely to find sulphites, including E227, in categories where browning and spoilage are concerns. Examples include some wines, dried fruits, fruit-based products, and certain potato or pickled items, depending on the country’s rules and the specific product.¹ In the U.S., wine labels must state “Contains Sulfites” when sulfites are at or above 10 mg/L.²

What can replace Calcium bisulphite?

Alternatives depend on the job to be done:

• For preserving against molds and yeasts: potassium sorbate or sodium benzoate are common options in suitable foods.
• For limiting browning: ascorbic acid and citric acid help reduce oxidation in cut fruits and beverages.
• For flavor stability and oxidation control: extracts of rosemary can help in some fat-containing foods.

How is Calcium bisulphite made?

Industrially, calcium bisulphite is typically produced by absorbing sulphur dioxide gas into a slurry or solution of calcium hydroxide or calcium carbonate, forming an aqueous solution of Ca(HSO3)2. The result is usually handled and sold as a solution rather than a dry powder because sulphite salts can be unstable in air and moisture.³

Is Calcium bisulphite safe to eat?

Regulators have evaluated sulphur dioxide and sulphites (E220–E228) as a group. The European Food Safety Authority (EFSA) confirmed a group acceptable daily intake (ADI) of 0.7 mg per kg body weight per day, expressed as SO2, while noting that some consumers may exceed this in high-intake scenarios for certain foods.¹ The Joint FAO/WHO Expert Committee on Food Additives (JECFA) also set a group ADI of 0–0.7 mg/kg body weight per day, expressed as SO2.⁴

Labeling helps consumers identify when sulphites are present. In the United States, sulfites must be declared if they are added as an ingredient or if the finished food contains 10 parts per million (ppm) or more.⁵ In the European Union (EU), “sulphur dioxide and sulphites” must be declared when present above 10 mg/kg or 10 mg/L, expressed as SO2.⁶

Does Calcium bisulphite have any benefits?

For manufacturers and consumers, the main benefits are practical:

• Keeps foods looking and tasting closer to fresh by slowing browning and spoilage.
• Helps extend shelf life, which can reduce food waste.¹

Who should avoid Calcium bisulphite?

A small portion of the population, especially some people with asthma, can be sensitive to sulphites and may experience reactions at levels tolerated by others.¹ If you’ve had reactions to sulphites, talk with your clinician and check labels carefully for “sulphites” or named sulphite additives such as E227.

Myths & facts

• Myth: “Sulfites are one of the major allergens.” Fact: In the U.S., sulfites are not classified as one of the major food allergens, but they must be declared when added or when present at 10 ppm or more in the finished food.⁵
• Myth: “You can’t tell if wine has sulfites.” Fact: U.S. wine labels must say “Contains Sulfites” when levels are 10 mg/L or higher.²
• Myth: “All sulphites are the same ingredient.” Fact: There are several related additives in the group, including sulphur dioxide, sodium and potassium salts, and calcium salts (like E227). Rules and typical uses can differ by salt and by food category.¹

Calcium bisulphite in branded foods

• Read the ingredient list for “calcium bisulphite,” “calcium bisulfite,” “E227,” or a catch‑all “sulphites” statement.
• Beverages like wine often carry a “Contains Sulfites” statement when required by law.²
• If you avoid sulphites, scan packaged dried fruits, juices, pickled items, and potato products, where sulphites may appear depending on the product and country.¹

References

Footnotes

1. Re-evaluation of sulphur dioxide (E 220) and sulphites (E 221–228) as food additives — EFSA. https://www.efsa.europa.eu/en/efsajournal/pub/4438 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

2. 27 CFR §4.32(e) — Mandatory label information; “Contains sulfites.” eCFR (U.S. TTB). https://www.ecfr.gov/current/title-27/part-4/section-4.32 ↩ ↩² ↩³

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

4. Sulfur dioxide and sulfites — JECFA evaluation (group ADI 0–0.7 mg/kg bw as SO2). WHO/FAO. http://www.inchem.org/documents/jecfa/jecmono/v048je06.htm ↩

5. 21 CFR §101.100 — Food; exemptions from labeling requirements (sulfiting agents declaration). eCFR. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-101/section-101.100 ↩ ↩²

6. Regulation (EU) No 1169/2011, Annex II — Substances causing allergies or intolerances (sulphur dioxide and sulphites >10 mg/kg or L). EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32011R1169 ↩