E228 / Preservatives
Potassium hydrogen sulfite
Safety in brief
Safe in moderation
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.
- 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 hydrogen sulfite (chemical formula KHSO3) is a sulfite preservative and antioxidant used mainly in winemaking and brewing to prevent oxidation and microbial spoilage. It works by releasing sulfur dioxide (SO2), which inhibits spoilage bacteria and yeast. Food-use permission depends on the country, food and amount. EFSA assesses risk; it does not grant food-use authorisations. Like other sulfites, it can cause allergic-type reactions or respiratory symptoms in sensitive individuals, including some people with asthma.
Also appears on labels as: Potassium hydrogen sulfite, Potassium bisulfite, Potassium metabisulfite (in solution), KHSO3, E228, E 228, E-228, Sulfur dioxide potassium salt, Potassium bisulphite, Food preservative potassium hydrogen sulfite, Potassium metabisulphite, INS 228.
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
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.
Selected research on E228
How to read study types- 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 E228
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 E228: Potassium hydrogen sulphite. 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 E228 (Potassium hydrogen sulphite) 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 bisulfite (potassium hydrogen sulfite) 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 15 listed food-use conditionsPotassium BisulphiteHealth Canada: List of Permitted Preservatives. List published ; item P.3.
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 228. 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 228. 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
- 3 source summaries, with publication dates and study types. Several publications may describe the same study population.
- Official assessment reference
- EFSA opinion located for E228. 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 in moderation |
| WHO | Safe in moderation |
| EFSA | Safe |
| FSANZ | Safe |
| Japan | Safe |
| UK FSA | Safe |
| Health Canada | Safe |
An official EFSA assessment for E228
An official scientific opinion covering E228 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 E228?
The recorded EatMatrix rating for E228 (Potassium hydrogen sulfite) is “Safe in moderation”. 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 E228 vegan, halal or gluten-free?
According to our ingredient data for Potassium hydrogen sulfite — 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 E228 and why is it used?
Potassium hydrogen sulfite (chemical formula KHSO3) is a sulfite preservative and antioxidant used mainly in winemaking and brewing to prevent oxidation and microbial spoilage. It works by releasing sulfur dioxide (SO2), which inhibits spoilage bacteria and yeast. Food-use permission depends on the country, food and amount. EFSA assesses risk; it does not grant food-use authorisations. Like other sulfites, it can cause allergic-type reactions or respiratory symptoms in sensitive individuals, including some people with asthma.
Does E228 contain allergens?
No known allergens are recorded for Potassium hydrogen sulfite, 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.