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Preservative

OCTYLISOTHIAZOLINONE

CAS 26530-20-1
18

Safety score · 0–100

Avoid

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

A potent isothiazolinone biocide — works very well but is a strong skin sensitizer. EU bans it in leave-on cosmetics and restricts rinse-off concentrations; widely flagged in contact dermatitis registries.

Skin benefits

  • Effective anti-mould and anti-bacterial activity
  • Active at very low concentrations

Known concerns

  • Strong skin sensitizer with high allergy rates
  • EU bans use in leave-on products (Annex V)
  • Highly aquatic toxic
  • Linked to widespread contact dermatitis

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.