E224

What is E224?

Potassium metabisulphite (PMBS) — a common sulphite preservative in wine and dried fruit, assessed with the E220–E228 group alongside sodium metabisulphite.

Quick answer

Potassium metabisulphite (E224), often abbreviated PMBS or written potassium metabisulfite, is a sulphite used as a preservative and antioxidant in wine, dried fruit, potato products and other foods. It is assessed with the wider sulphite group (E220–E228). It is permitted in Australia/NZ, the EU and the US within set limits, and must usually be declared when present at 10 milligrams per kilogram or more. EFSA's 2022 follow-up withdrew the temporary group Acceptable Daily Intake for sulphur dioxide–sulphites because toxicity data remained inadequate, and instead used a margin-of-exposure approach that raised a safety concern for high consumers in most population groups. Regulators and allergy bodies have long noted that sulphites may be associated with asthma-like symptoms in some sensitive individuals. Goodnessly rates it Avoid.

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What is potassium metabisulphite?

Potassium metabisulphite (E224) is an inorganic sulphite salt (also called potassium pyrosulphite). In solution it releases sulphur dioxide, which provides the preservative and antioxidant effect. It belongs to the wider sulphite group that also includes sulphur dioxide (220), sodium sulphite (221), sodium bisulphite (222), sodium metabisulphite (223) and related salts (226–228). It is especially familiar in winemaking as an alternative or complement to sodium metabisulphite. On labels you may see "potassium metabisulphite", "potassium metabisulfite" (US spelling), "PMBS", "224", or the class name "preservative" / "antioxidant" with the number.

What's it used for?

Preserving wine, beer and cider and managing fermentation (a very common winemaking sulphite)
Preserving dried fruit and limiting browning in dried fruit and vegetables
Limiting spoilage and browning in some potato products and processed foods
Used in some seafood processing where permitted and in selected condiments

Where you'll find E224 on the shelf

Potassium metabisulphite is one of the sulphites you are most likely to see named on wine and dried-fruit labels.

Wine, beer & cider

Dried fruit & dried vegetables

Potato products & crisps

Some seafood products

Selected condiments & sauces

Home winemaking kits

Is potassium metabisulphite safe? What the research says

Potassium metabisulphite is regulated as part of the sulphur dioxide–sulphites group. It remains widely permitted, carries mandatory declaration rules in major markets, and sits under EFSA's 2022 group assessment that withdrew the temporary ADI and flagged a safety concern for high consumers. Sulphites have long been associated in clinical and regulatory literature with adverse reactions in some people with asthma.

Region	Status	What this means
AU/NZ Australia & New Zealand (FSANZ)	Permitted; declare ≥10 mg/kg	Permitted under the Food Standards Code for specified foods at maximum levels (often expressed as sulphur dioxide equivalents). Added sulphites must be declared when present at 10 milligrams per kilogram (10 mg/kg) or more. FSANZ and Australian allergy guidance note that sulphite sensitivity is more common among people with asthma.
EU European Union (EFSA)	Permitted; ADI withdrawn 2022	Authorised as E224 within the E220–E228 group, including specified wine uses under EU wine rules. EFSA's 2016 re-evaluation set a temporary group ADI of 0.7 milligrams of SO₂ equivalents per kilogram of body weight per day. The 2022 follow-up withdrew that temporary ADI because the toxicity database remained inadequate, applied a margin-of-exposure approach (reference point 38 mg SO₂ equivalents/kg bw/day; assessment factor 80), and concluded this raises a safety concern for estimated dietary exposures in both refined and maximum-permitted-level scenarios for most population groups. EFSA also restated the need to further investigate hypersensitivity among some sensitive consumers.
US United States (FDA)	GRAS; declare ≥10 ppm	Potassium metabisulfite is listed as generally recognized as safe under 21 CFR 182.3637 when used in accordance with good manufacturing practice, with carve-outs including meats, foods recognised as a source of vitamin B1, and fruits or vegetables intended to be served or sold raw/fresh. Sulfiting agents must generally be declared when present at 10 parts per million (10 mg/kg) or more; functional sulfites must be declared regardless of level.

Wording matters here: regulators describe sulphite-related breathing difficulties in some sensitive people — particularly some people with asthma — as a recognised hypersensitivity concern, not as proof that potassium metabisulphite will cause asthma in the general population. Prevalence estimates vary; ASCIA and similar bodies advise sulphite-sensitive individuals to read labels carefully.

📰 Recent developments Last checked September 2026

EFSA 2022 follow-up (group E220–E228): withdrew the temporary group ADI; used a margin-of-exposure approach and concluded estimated intakes raise a safety concern for high consumers in all population groups except adolescents (refined scenario). Potassium metabisulphite (E224) is included in that group assessment.
Hypersensitivity data gaps: EFSA restated its recommendation to further investigate hypersensitivity or intolerance among some sensitive consumers, because knowledge gaps remain.
Label thresholds unchanged: AU/NZ and US still generally require sulphite declaration at or above 10 mg/kg (10 ppm), so wine and dried-fruit labels remain the practical first check.

This section is checked periodically rather than continuously — if you're reading this well after the date above, it's worth confirming nothing has changed before citing it.

Who might want to limit or avoid it

People with asthma or a known sulphite sensitivity, given longstanding clinical and regulatory notes that sulphites may be associated with wheezing or other reactions in some sensitive individuals
High consumers of wine, dried fruit or other sulphited foods, given EFSA's 2022 finding that estimated intakes raise a safety concern for high consumers in most age groups
Anyone who prefers to minimise preservative sulphites and can choose unsulphited dried fruit or lower-sulphite wine options where available

Goodnessly rates E224 Avoid. Potassium metabisulphite remains permitted within set limits in Australia/NZ, the EU and the US, but EFSA's 2022 withdrawal of the temporary group ADI for E220–E228, the margin-of-exposure concern for high consumers, and the well-recognised association between sulphites and adverse reactions in some sensitive people — including some people with asthma — place it in our highest-caution category.

Additives 1

E224 – Potassium metabisulphite

Common sulphite preservative (PMBS), rated Avoid by Goodnessly. May be associated with reactions in some sulphite-sensitive people.

How to spot it on a label

E224 and related sulphites must usually be declared when at or above 10 mg/kg. Look out for:

Potassium metabisulphite / potassium metabisulfite / PMBS
224 or E224
Preservative (224) or antioxidant (224)
Other sulphites: 220–223, 226–228

Especially common on wine, dried fruit and some potato-product or seafood labels.

Related additives

Frequently asked questions

What is Potassium metabisulphite (E224) made from?

Potassium metabisulphite is an inorganic sulphite salt manufactured for use as a food preservative and antioxidant. In solution it releases sulphur dioxide. It belongs to the sulphite group (E220–E228). Small amounts of sulphites can also occur naturally in some foods.

Why is potassium metabisulphite so common in wine?

Winemakers use sulphites, including potassium metabisulphite, to help control unwanted microbes and limit oxidation. Residual sulphite must usually be declared when at or above 10 mg/kg. That technological use is why E224 appears so often on wine labels — it is not evidence of a unique hazard beyond the wider sulphite group assessment.

Can potassium metabisulphite affect people with asthma?

Sulphites have long been associated in clinical and regulatory literature with adverse reactions — including asthma-like symptoms such as wheezing — in some sensitive individuals, and sensitivity appears more common among people who already have asthma. That is an association for a sensitive subgroup, not evidence that potassium metabisulphite causes asthma in the general population. If you have asthma or a known sulphite sensitivity, check labels and follow clinical advice.

Does Goodnessly rate E224 as safe, caution or avoid?

Goodnessly rates E224 (Potassium metabisulphite) as Avoid. It remains permitted within set limits, but EFSA's 2022 group ADI withdrawal and high-consumer concern, plus the recognised association with reactions in some sulphite-sensitive people, place it in our highest-caution category.

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