About
What it is and where it shows up.
Sodium metabisulfite is an inorganic sulfite compound that releases sulfur dioxide (SO2) when dissolved in water; it functions as an antimicrobial preservative and antioxidant in foods such as wines, fruit juices, dried fruits, and seafood products. It prevents oxidative browning, inhibits microbial and fungal growth, and extends product shelf life.
Safety summary
The regulatory and scientific consensus.
The EFSA FAF Panel withdrew its temporary group ADI of 0.7 mg SO2 equivalents/kg bw/day in 2022 due to persistent toxicological data gaps, adopting a margin-of-exposure (MOE ≥ 80) approach and noting that current dietary exposure levels may be of concern. Sulfite-sensitive individuals—particularly asthmatics—are at risk of severe allergic reactions including bronchoconstriction and anaphylaxis. The FDA revoked GRAS status for use on fresh fruits and vegetables in 1986 following more than 700 documented adverse-reaction reports.
Regulatory landscape
What food-safety regulators have decided.
| Jurisdiction | Status | Note |
|---|---|---|
| EFSA (European Food Safety Authority) (European Union) | Restricted | Authorised as a food additive under Regulation (EC) No 1333/2008, Annex II and III, with specifications in Commission Regulation (EU) No 231/2012. A temporary group ADI of 0.7 mg SO2 equivalents/kg bw/day (covering E220–E228 as a class) was established in 2016 but formally withdrawn in the November 2022 EFSA follow-up opinion owing to insufficient biological and toxicological data. EFSA now requires a Margin of Exposure of at least 80; current permitted usage levels may exceed this threshold and are flagged as potentially of concern.source |
| FDA (Food and Drug Administration) (United States) | Restricted | GRAS as a chemical preservative under 21 CFR 182.3766 for most food applications. In 1986, FDA revoked GRAS status for use on fresh fruits and vegetables following documented adverse reactions; exemptions remain for precut or peeled (non-whole raw) potatoes and grapes. Mandatory ingredient label declaration is required when present at functional levels in food.source |
| FSSAI (Food Safety and Standards Authority of India) (India) | Approved | Listed as INS 223 (Sodium Metabisulphite, Food Grade) under the Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011, Section 3.2.7. Specified as colourless crystals or white-to-yellowish crystalline powder with an odour of sulfur dioxide, soluble in water and insoluble in ethanol. Permitted in specified food categories within prescribed limits per FSSAI Appendix A.source |
Who should approach with care
Whose guidance would steer them away.
Sulfite Sensitivity — Sulfite-sensitive individuals can experience severe hypersensitivity reactions—including bronchoconstriction, urticaria, and anaphylaxis—even at low dietary exposure levels, as documented in FDA adverse-reaction reports and EFSA safety evaluations.
Other — Asthmatics represent the highest-risk sensitive population; FDA received over 700 adverse-reaction reports linked to sulfite ingestion by 1986, prompting its ban on fresh-produce applications specifically to protect asthmatic consumers.
Infants — Sulfites can degrade thiamine (vitamin B1) in treated foods, posing a nutritional risk for infants whose diets may rely on sulfite-preserved products; no specific infant ADI has been established following EFSA's 2022 ADI withdrawal.
Children — EFSA's 2022 follow-up opinion noted that dietary exposure to sulfites at current permitted levels can exceed tolerable thresholds particularly for high-level consumers in younger age groups, warranting reduced intake.
— Sulfur dioxide released by metabisulfite can irritate gastrointestinal mucosa and may exacerbate symptoms in individuals with irritable bowel syndrome or other gut sensitivities.
Research citations
The sources behind this verdict.
- 1FDA. Food Additive Status List — Sodium Metabisulfite (21 CFR 182.3766). fda.gov
- 2WHO. JECFA Food Additives and Contaminants Database — Sodium Metabisulfite (chemID 1824). apps.who.int
- 3EFSA. Update of the dietary exposure to sulfur dioxide (E 220)–potassium bisulfite (E 228) with alternative maximum levels when used as food additives, 2025. efsa.europa.eu
- 4EFSA. Follow-up of the re-evaluation of sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228), 2022. efsa.europa.eu
- 5EFSA. Scientific Opinion on the re-evaluation of sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228) as food additives, 2016. efsa.europa.eu
Independently researched6 citations