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Preservative

QUATERNIUM-51

CAS 1463-95-2
50

Safety score · 0–100

Moderate

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

A halogenated quaternary ammonium preservative (related to benzalkonium). Effective antimicrobial but a known eye and skin irritant, used at low percent only.

Function

ANTISTATIC

Skin benefits

  • Antimicrobial preservative quat
  • Effective against bacteria and fungi
  • Stable across pH range

Known concerns

  • Quaternary ammonium skin and eye irritant
  • Sensitization potential
  • Halogenated benzyl moiety raises persistence flag

References

EU

EU CosIng database

European Commission cosmetic ingredient registry: regulatory status, restrictions, authorised functions.

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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve, so always read the physical product label and consult a healthcare professional for personal concerns.