Potassium Sulfite (E225)
Also known as: POTASSIUM SULFITE, E225
Potassium sulfite is approved as E225 in the EU and recognized as GRAS in the US (21 CFR 182.3637, as potassium sulfite). Like other sulfites, it can trigger reactions in sulfite-sensitive individuals (roughly 1% of the population, more common in people with asthma).
What it is
Potassium sulfite (K2SO3), the potassium salt of sulfurous acid. Used as an antioxidant and preservative — same functional class as sodium sulfite (E221) and potassium metabisulfite (E224).
Antioxidant and preservative.
Why it's flagged
- Sulfite sensitivity / asthma in a subgroup of consumers
- Required to be labeled when present at >=10 ppm (FDA & EU)
What regulators actually say
"Sodium sulfite... is generally recognized as safe when used in accordance with good manufacturing practice, except that it is not used in meats; in food recognized as a source of vitamin B1; on fruits or vegetables intended to be served raw to consumers or sold raw to consumers, or to be presented to consumers as fresh."
"The existing ADI was withdrawn because adequate toxicity data were not available... The calculated MOEs raises some safety concerns for high consumers of foodstuffs that contain sulfites."
Regulatory status
United States — FDA
GRAS as potassium sulfite (21 CFR 182.3637); declared on label when >=10 ppm
European Union — EFSA
Approved as E225; group ADI 0.7 mg SO2 equivalent/kg bw/day
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