The Lab
Specimen No. 0225
CautionSyntheticfood dyesfood additive

Patent Blue V

E131 · Food Blue 5 · Acid Blue 3

Synthetic triarylmethane blue dye (not an azo dye, and not one of the six "Southampton" colours). The documented concern is hypersensitivity/allergic reactions; it is not approved for food in the US.

medium confidence
Researched July 7, 2026

Concerns

  • EFSA set an ADI of 5 mg/kg bw/day but noted high-consuming toddlers and children can exceed it; asthmatics and aspirin-intolerant individuals are flagged as particularly susceptible to reactions (EFSA 2013)
  • Severe IgE-mediated anaphylaxis to Patent Blue V is documented, but the reported cases come from high-dose surgical use as a lymphatic-mapping dye (sentinel-node biopsy), not from dietary exposure (Mertes et al. 2008; Dewachter et al. 2006)

Regulatory flags

  • IARC Class: NL
  • EDC Status: None
  • Regulatory: US: not approved for food; EU: permitted (E 131); ADI 5 mg/kg bw
  • Evidence Grade: B

Commonly found in

EU confectionerySoft drinks (EU)Some medicinesSavory coatings (EU)

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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