Food additive databasebleaching agent, preservative, antioxidantChecked 2026-10-02

Potassium Pyrosulfite (Potassium Hydrogen Sulfite or Potassium Metabisulfite) ピロ亜硫酸カリウム（別名亜硫酸水素カリウム又はメタ重亜硫酸カリウム）

Designated additivePermitted in the EU (E224)

Purpose: bleaching agent, preservative, antioxidant
On the label: “酸化防止剤（亜硫酸塩）” (antioxidant (sulfites)), “保存料（亜硫酸K）” (preservative (potassium sulfite)), “漂白剤（亜硫酸塩）” (bleaching agent (sulfites)), “重亜硫酸K” (potassium bisulfite)
Name in the List of Designated Additives: ピロ亜硫酸カリウム（別名亜硫酸水素カリウム又はメタ重亜硫酸カリウム） (No. 338)

In Japan

One of the sulfites (also called potassium hydrogen sulfite or potassium metabisulfite). As a bleaching agent, preservative and antioxidant, it can be used in dried gourd strips (kanpyo), dried fruits, fruit wine and similar foods, with upper limits on the residue as sulfur dioxide. It cannot be used in sesame, beans (legumes) or vegetables.
Under the Food Labeling Standards, when used as a preservative, antioxidant or bleaching agent, the purpose name is written alongside, and the short names “亜硫酸塩” (sulfites), “亜硫酸K” (potassium sulfite), “重亜硫酸K” (potassium bisulfite) and others can be used (example: “酸化防止剤（亜硫酸塩）” (antioxidant (sulfites))).
The standards for use for sulfites were revised in the April 2026 revision of the standards and specifications.

Japan's standards for use

Specified as the residue as sulfur dioxide
Dried gourd strips (kanpyo): less than 5.0 g/kg
Dried fruits (excluding raisins): less than 2.0 g/kg; raisins: less than 1.5 g/kg
Konjac flour: less than 0.90 g/kg
Dried potatoes, gelatin, Dijon mustard: less than 0.50 g/kg
Fruit wine, other alcoholic beverages (zasshu): less than 0.35 g/kg. Soft drinks made from grape wine with the alcohol removed, and the grape juice added to them, are also less than 0.35 g/kg
Other foods: less than 0.030 g/kg
Must not be used in sesame, beans (legumes) or vegetables
And others (candied cherries, molasses, starch syrup (mizuame), amanatto, shrimp, etc.)

This is a summary of the standards for use. See the source list for the exact conditions.

In the EU

It is on the EU list of food additives (Regulation (EC) No 1333/2008, Annex II) as E224.
The EU treats sulfites as one of the allergens, and foods containing more than 10 mg per kg (or per L), calculated as sulfur dioxide, must carry a prominent allergen declaration (EU Regulation 1169/2011).
The EFSA ADI (0.7 mg) is expressed as the amount converted to sulfur dioxide, for sulfites as a group.
In its 2016 re-evaluation, EFSA set a temporary group ADI for sulfur dioxide and sulfites (E220 to E228) of 0.7 mg per kg of body weight per day, as sulfur dioxide. In its 2022 follow-up evaluation, it withdrew this, saying the toxicity data are insufficient to derive an ADI, and switched to an approach based on the margin of exposure (MOE). In that assessment, for high consumers (95th percentile) the estimated MOE was below the reference value of 80 in all age groups except adolescents, and EFSA concluded there is a safety concern.

When it is labeled under a shared name

Potassium Pyrosulfite (Potassium Hydrogen Sulfite or Potassium Metabisulfite) may be declared on the label in the same way as “亜硫酸塩”. See Sulfites for details.

Sources

Checked 2026-10-02. Rules and evaluations change over time. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.

This page lists facts stated in laws and in evaluations by public bodies; it is not a safety verdict. Additives used in Japan are approved by the government, which sets the foods and amounts they can be used in. The ADI is a guide to the amount that is considered safe to take every day over a lifetime.

Other substances used as bleaching agent, preservative, antioxidant

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