The Lab
Specimen No. 0216
CautionSyntheticpreservativefood additive

Sodium Metabisulfite

CAS 7681-57-4 · E223 · sodium pyrosulfite · sodium disulfite

A widely used sulfite preservative/antioxidant in wine, dried fruit and seafood (it releases SO2 in water). Safe for most people but a common trigger for sulfite-sensitive and asthmatic individuals; FDA requires labeling at 10 ppm or more.

high confidence
Researched July 7, 2026
Sodium Metabisulfite molecular structure
Specimen 0216Sodium Metabisulfite

Concerns

  • Sodium metabisulfite releases sulfur dioxide and behaves as a sulfiting agent, so it can trigger reactions in sensitive individuals — especially asthmatics (about 3-10% react) — from dermatitis, flushing, hypotension, abdominal pain and diarrhea to rare life-threatening asthmatic and anaphylactic reactions (Vally & Misso; Vally et al.)
  • FDA requires sulfiting agents present at 10 ppm or more in a finished food to be declared on the label (21 CFR 101.100) and prohibits sulfites on fruits and vegetables sold or served raw
  • EFSA's 2016 group re-evaluation set only a temporary ADI of 0.7 mg SO2 equivalents/kg body weight per day; EFSA withdrew this temporary ADI in 2022, finding the toxicity database inadequate to establish a safe intake

Regulatory flags

  • ⚑IARC Class: NL
  • ⚑EDC Status: None
  • ⚑Regulatory: US: GRAS w/ mandatory labeling >=10 ppm (21 CFR 101.100), banned on raw produce (1986); EU: E223, group ADI withdrawn (EFSA 2022)
  • ⚑Evidence Grade: A

Commonly found in

WineDried fruitFrozen/processed seafoodFruit juicesPickled foods

Last researched: July 7, 2026

Research disclaimer: This rating is based on available peer-reviewed research and regulatory assessments at the time of publication. It is not medical advice. Consult a qualified professional for personal health or skin concerns.

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