E224 / Preservatives
Potassium metabisulfite
Safety in brief
Safe
Recorded EatMatrix rating, not a new clinical review. The amount, your sensitivities and country rules still matter.
- Watch for
- Sulfite-sensitive people can have allergy-like reactions, including breathing symptoms. Many affected people also have asthma; asthma alone does not establish sulfite sensitivity.
- Selected research
- Higher estimated intake of additive-origin potassium metabisulfite was associated with more new type 2 diabetes diagnoses. This substance is named in the abstract's list of associations retained after adjustment for multiple tests. An association does not prove that it caused diabetes. Study details and limits.
- Our advice
- Check for sulfites on the label if you have a diagnosed sensitivity. Discuss suspected food-related breathing reactions with your clinician; do not try an oral challenge yourself. A country’s permission or labelling threshold cannot guarantee that a food suits you.
What it is
Potassium metabisulfite (chemical formula K2S2O5) is a sulfite preservative and antioxidant widely used in winemaking, beer, and dried fruit to block oxidation and unwanted microbial growth. It releases sulfur dioxide (SO2), the active preservative gas shared by all sulfite additives. Food-use permission depends on the country, food and amount. EFSA assesses risk; it does not grant food-use authorisations. As with other sulfites, sensitive individuals — especially some people with asthma — may experience allergic-type reactions.
Also appears on labels as: Potassium metabisulfite, Potassium pyrosulfite, K2S2O5, E224, E 224, E-224, Food preservative potassium metabisulfite, Potassium disulfite, Metabisulfite of potassium, Potassium pyrosulphite, Preservative E224, INS 224.
Dietary information
- Vegan
- Yes
- Halal
- Yes
- Gluten-free
- Yes
- Allergens
- Caution
Recorded ingredient information. Check the product label or certification: sources, other ingredients and cross-contact can vary.
Research & body effects
Newer sources to read for E224
- 2026 BMJ study of food additive preservatives and cancer incidence
Published January 7, 2026. A prospective observational study in the French NutriNet-Santé cohort; it includes this ingredient. Observational associations cannot by themselves establish that an additive causes a health outcome.
- BfR assessment of limitations in that study
Published March 17, 2026. The German risk-assessment institute discusses uncertainty in the findings. This assessment is separate from a country's rules on permitted food uses.
Bibliographic identity and the indexed study type checked October 4, 2026. The BMJ abstract and BfR communication were read; a complete review of the study's methods, supplements and the wider evidence remains pending. These links do not change EatMatrix's recorded rating.
Sulfites: sensitivity and longer-term exposure
What can happen in the body
Sulfite-sensitive people can have allergy-like reactions, including breathing symptoms. Many affected people also have asthma; asthma alone does not establish sulfite sensitivity. Sulfites help preserve food and its colour. Their practical benefit is preservation; that does not make them a nutrient you need to seek out.
FSANZ considers current food levels unlikely to pose a risk to most consumers, while recognising sensitive people and uncertainty in the older daily-intake assessment. EFSA’s European assessment raises concerns at higher estimated intakes. These authorities assessed different exposure data and assumptions.
FSANZ consumer guidance, updated November 2025 · EFSA safety assessment, 2022; corrected November 2025
What changed in the newer EFSA report
EFSA withdrew its temporary daily-intake limit in 2022 because the evidence remained inadequate to set one. The November 2025 correction revised exposure calculations and left that opinion’s conclusion unchanged.
A separate November 2025 report modelled six scenarios using possible changes to food-use limits. It estimated lower exposure in several scenarios. Some calculations also excluded measurements above the proposed limits or suspected illegal uses, so the decrease cannot be read as a measured improvement in people’s health. This was an exposure model, not a new human trial or a legal change.
EFSA exposure update, November 2025. Report methods, discussion and conclusion checked; the separate spreadsheet annex has not been fully reviewed here.
EatMatrix’s reading
Sensitivity, long-term dietary exposure and legal permission answer different questions. Group-level exposure modelling does not prove that this individual salt causes disease. Check for sulfites on the label if you have a diagnosed sensitivity. Discuss suspected food-related breathing reactions with your clinician; do not try an oral challenge yourself. A country’s permission or labelling threshold cannot guarantee that a food suits you.
Clinical guidance on the risks and interpretation of oral challenges.
Selected sources checked . The 2022 opinion’s corrected version was used. Indexed challenge records showed no linked correction or retraction in this check; that is not a complete version audit. Where present, 2026 cohort findings below remain separate. This review does not replace a personal assessment or complete every country’s food-use rules.
What selected 2026 human research means for E224
Type 2 diabetes: what was found
Higher estimated intake of additive-origin potassium metabisulfite was associated with more new type 2 diabetes diagnoses. This substance is named in the abstract's list of associations retained after adjustment for multiple tests. An association does not prove that it caused diabetes.
The French NutriNet-Santé analysis included 108,723 people and 1,131 new diagnoses, with a median follow-up of 8.05 years. Diets were recorded repeatedly, including food brands. Researchers estimated additive intake and adjusted for factors such as diet, body size and smoking. They did not randomly assign people to eat this additive.
Blood pressure and cardiovascular outcomes
A May 2026 analysis associated potassium metabisulfite with new hypertension after multiple-test adjustment. This does not mean that every cardiovascular outcome was associated with this additive.
This analysis included 112,395 people overall, with 5,544 new hypertension cases and 2,450 cardiovascular events in the respective analyses. It comes from the same NutriNet-Santé cohort as the diabetes and cancer publications; these are different outcomes, not three independent replications.
EatMatrix’s reading
Keep the specific potassium salt separate from the combined sulfite group. Foods and drinks, including alcohol, can complicate interpretation of dietary exposure.
These findings deserve follow-up. Estimated intake, other features of the foods people ate and differences between volunteers can still influence the results. Most participants were women; the results may not transfer directly to children or every country. A proposed mechanism from cells or animals is not a demonstrated mechanism in people eating ordinary food.
A useful next step when choosing food
Compare the whole food: its ingredients, fibre, salt, free sugars, saturated fat and how often you eat it. Choose a varied pattern with more minimally processed foods where practical. Removing one E number alone has not been shown by these studies to prevent diabetes or heart disease.
Selected abstract, main-text methods/results and funding checked . Funders include European and French public research bodies; the authors declare no competing interests. Supplementary tables could not be inspected here, so individual corrected estimates are not reproduced. Indexed records showed no linked correction or retraction in this check; that is not proof none exists. This is a selected editorial review, not a complete clinical or current-country-use assessment. It does not change EatMatrix’s recorded rating or country permissions.
Selected research on E224
How to read study types- Observational studyPreservatives, hypertension and cardiovascular disease in the French cohort
Higher potassium metabisulfite intake was linked to new hypertension after multiple-test adjustment. This is the same French cohort as the cancer and diabetes papers, not independent replication or proof of causation.
- Expert critiqueGerman risk institute (BfR) on the BMJ preservatives study
Points to chance findings from many tests, diet effects hard to separate (sulfites track wine, for example) and self-reported intake. Sees no reason to change EFSA’s assessments.
- Observational studyBMJ study of preservatives and cancer in 105,260 French adults
Linked higher intake of potassium metabisulfite with overall and breast cancer. It observed diets and cannot show the additive caused the cancers. 11 of the 17 preservatives studied showed no link.
- Observational studyPreservatives and type 2 diabetes in 108,723 French participants
Higher additive-origin potassium metabisulfite intake was linked to new type 2 diabetes in a French cohort. It is one of 12 associations retained after multiple-test adjustment. Diet was observed, not assigned; this does not show causation.
- Dietary exposure estimateEFSA models alternative limits for sulfur dioxide and sulfites
Six scenarios explored possible food-use limits. Several estimated lower exposure, but changes in which measurements were included prevent a simple comparison with 2022. This modelling is neither a human health trial nor a change in law.
- Regulator reviewEFSA follow-up review of sulfur dioxide and sulfites
Industry supplied no new biological or toxicological data addressing the gaps, and the literature did not resolve them. EFSA withdrew its temporary daily-intake limit and raised concern at estimated higher exposures. The November 2025 exposure correction left the conclusion unchanged.
Publisher amendment:
- Regulator reviewEFSA re-evaluation of sulfur dioxide and sulfites
Kept a safe daily limit of 0.7 mg per kg of body weight but made it temporary because the data were limited. Estimated intake was above it in all age groups.
Earlier source summaries checked ; latest additions checked . See the detailed research section for what was read and the remaining limits. This is a selection of sources, not a complete literature review. Authority assessments apply to the uses and places they cover.
Health notes from our ingredient record
- Can trigger reactions (flushing, hives, wheezing, or in rare severe cases anaphylactoid symptoms) in sulfite-sensitive individuals, especially some people with asthma.
- Labelling rules and thresholds depend on the market and food. See the checked country sources below.
Other references from our ingredient record
These links come from the original ingredient record. They are separate from the source reviews above and have not all been checked for the exact ingredient, amount consumed or claim. Dates are shown newest first.
- 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 — EFSA Panel on Food Additives, EFSA Journal (2016). Official EFSA scientific opinion (bibliographic reference, imported 2026-10-13). It covers the additive as a group assessment and is not an individual human study; read the opinion for its findings.
Country rules
Country checks for E224
Permission depends on the market, type of food, amount and conditions. A scientific opinion or an E-number alone does not establish a legal use. These checks are separate from the stored EatMatrix rating.
Compare all eight markets and their sources
| Market | What is checked |
|---|---|
| European Union | Regulation (EC) 1333/2008, Annex II Part B, version , contains the exact code E224: Potassium metabisulphite. Listing alone does not allow every food use. Part E food categories, limits, specifications and applicable later acts still need a product-specific check. Source read: . |
| Great Britain | The FSA register record for E224 (Potassium metabisulphite) lists “Authorised” in England, Scotland and Wales. Register updated: 01 April 2025; record checked: . Food-specific conditions and specifications still need a separate legal check. |
| United States | Selected US conditions for Potassium metabisulfite Official federal text current through ; read . Food uses, limits and exceptionsFood categories excluded by this provision The named sulfiting agent is GRAS under good manufacturing practice, except in meats, foods recognised as a source of vitamin B1, and fruit or vegetables intended to be served or sold raw, or presented to consumers as fresh. This is a scoped restriction, not a ban on every food containing sulfites. What the 10 ppm label rule means An added sulfiting agent with no technical effect in the finished food can qualify for the incidental-additive exemption only when no detectable sulfite remains. The rule defines detectable as 10 ppm (10 mg/kg) or more in the finished food. Added preservatives with a technical effect have their own ingredient-name and function declaration requirements. The 10 ppm figure is a labelling threshold, not a personal safe dose. What a sensitive reader can do FDA notes that sulfites can cause reactions, including asthma symptoms in sensitive people. Read the ingredient list for the named sulfite. If you have a diagnosed sensitivity, follow your care team’s advice rather than treating legal use or the labelling threshold as proof of personal tolerance. EatMatrix’s reading: a legal use condition answers where and how an ingredient may be used. It is not a test of your product, a personal safe intake or a claim that the ingredient benefits your body. Match the named substance, food and amount. Other federal provisions, food standards, state rules and later changes may also apply; this is a selected source review, not a complete product-compliance decision. |
| Northern Ireland | Review pending. Check the applicable EU rules and territory arrangements; the GB register alone does not establish this status. FSA guidance is a starting source, not a verified permission for this entry. |
| Canada | Named food-use records located. Health Canada lists the preparations below for specified foods and purposes. This is conditional permission for those uses, not approval of every product or a personal safety verdict. Only the named records and conditions below were located. Exact composition and specifications still need matching. Source tables captured . List publication dates are shown separately. Good Manufacturing Practice (GMP) is a condition of use, not an unlimited amount or a recommended intake. Food and Drug Regulations B.16.003 requires the listed source, purpose, amount and other conditions to match. The official consolidation read was current to 21 September 2026; product specifications and applicable later changes still need checking. Read 16 listed food-use conditionsPotassium MetabisulphiteHealth Canada: List of Permitted Preservatives. List published ; item P.6.
EatMatrix reading: match the exact preparation and food first. A manufacturing limit is not an acceptable daily intake (ADI). A label without the amount cannot establish exposure, and an unlisted name here does not establish a ban. |
| Australia | Permitted in specified foods, subject to limits. The selected Schedule 15 rows include INS 224. Examples, calculated as sulfur dioxide:
These are food concentrations, not daily intake targets. Mixtures of additives serving the same purpose must also meet the Code’s combined-use rule. Other foods, specifications and product conditions need their own check. Label check: added sulphites at 10 mg/kg or more require a declaration using the name “sulphites”. This is a declaration threshold, not a guarantee against an individual reaction or permission to add this substance. Schedule 15, compilation F2026C00407 (2026-04-30); Standard 1.3.1, sections 4 and 6 (2024-09-13); Schedule 9, mandatory declarations (2021-02-25). Latest register versions checked . The joint Code applies in Australia and New Zealand; product-specific provisions still matter. |
| New Zealand | Permitted in specified foods, subject to limits. The selected Schedule 15 rows include INS 224. Examples, calculated as sulfur dioxide:
These are food concentrations, not daily intake targets. Mixtures of additives serving the same purpose must also meet the Code’s combined-use rule. Other foods, specifications and product conditions need their own check. Label check: added sulphites at 10 mg/kg or more require a declaration using the name “sulphites”. This is a declaration threshold, not a guarantee against an individual reaction or permission to add this substance. Schedule 15, compilation F2026C00407 (2026-04-30); Standard 1.3.1, sections 4 and 6 (2024-09-13); Schedule 9, mandatory declarations (2021-02-25). Latest register versions checked . The joint Code applies in Australia and New Zealand; product-specific provisions still matter. |
| Japan | Review pending. The relevant list, identity and use standards need an additive-specific check. CAA food-additive lists is a starting source, not a verified permission for this entry. |
Sources & review status
Check what each source covers: an authority’s conclusion, a research finding and a country’s legal permission answer different questions.
What this guide covers
- Selected research
- 7 source summaries, with publication dates and study types. Several publications may describe the same study population.
- Official assessment reference
- EFSA opinion located for E224. Identity and code coverage checked; full findings review pending.
- Original ingredient record
- 1 research link; newest recorded date: . Sources added separately to this guide are not included in this count.
This guide brings together our ingredient record and the dated sources shown here. Missing information describes a gap in this guide; it does not mean an ingredient is untested, safe or harmful. This is not a complete review of every study, preparation or current country rule. The amount in a product and how it is used still matter.
How to read the ratings, research and country checksAgency labels recorded by EatMatrix
These are imported database classifications, not verified current statements from each authority. Use the dated official sources below for their actual scope and conclusions.
| Authority | Database label |
|---|---|
| FDA | Safe |
| WHO | Safe |
| EFSA | Safe |
| FSANZ | Safe |
| Japan | Safe |
| UK FSA | Safe |
| Health Canada | Safe |
An official EFSA assessment for E224
An official scientific opinion covering E224 exists. A missing research link or rating in our database does not mean this additive has never been assessed. This reference identifies the document; it does not replace a review of its findings, later research or current food-use rules.
EFSA: Follow-up of the re-evaluation of sulfur dioxide and sulfites (E220–E224 and E226–E228)
- Published
- Publisher amendment
- Codes covered by this reference
- E220, E221, E222, E223, E224, E226, E227, E228
- Source type
- EFSA scientific opinion, not an individual human trial
The publisher records an erratum correcting exposure calculations following re-analysis of analytical data. Use the amended publisher version rather than an older downloaded copy.
EatMatrix checked this reference’s identity and code coverage on . The full evidence review, an exhaustive check for subsequent publications and corrections, and market-specific permissions remain pending. This does not change the recorded EatMatrix rating above.
Database updated: . What does an E number mean on a food label?
Common questions
Frequently asked questions
What is EatMatrix's recorded rating for E224?
The recorded EatMatrix rating for E224 (Potassium metabisulfite) is “Safe”. It is calculated from labels stored in our ingredient database. These labels are not verified current regulator decisions or country permissions. A database update date is not a scientific review date.
Is E224 vegan, halal or gluten-free?
According to our ingredient data for Potassium metabisulfite — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E224 and why is it used?
Potassium metabisulfite (chemical formula K2S2O5) is a sulfite preservative and antioxidant widely used in winemaking, beer, and dried fruit to block oxidation and unwanted microbial growth. It releases sulfur dioxide (SO2), the active preservative gas shared by all sulfite additives. Food-use permission depends on the country, food and amount. EFSA assesses risk; it does not grant food-use authorisations. As with other sulfites, sensitive individuals — especially some people with asthma — may experience allergic-type reactions.
Does E224 contain allergens?
No known allergens are recorded for Potassium metabisulfite, with a caution: sulfites.
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This page shows information and classifications recorded in our ingredient database. Current scientific and market-specific verification remains pending as described above. It is general information, not medical advice.