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Thickener

ISOPRENE/PENTADIENE COPOLYMER

CAS 31303-93-2
65

Safety score · 0–100

Fine

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

An unsaturated diene copolymer of isoprene and pentadiene — used as a viscosity controller. Bulk polymer is inert, but residual isoprene (IARC 2B) and reactive diene monomers warrant a cautious Fine tier.

Function

VISCOSITY CONTROLLING

Skin benefits

  • Provides viscosity control in cosmetic films
  • Improves wear time of coatings
  • Elastic polymer flexibility

Known concerns

  • Residual isoprene monomer is IARC Group 2B (possibly carcinogenic)
  • Pentadiene monomer is reactive and irritating
  • Public toxicology data on this INCI is sparse
  • Polymer purity varies significantly by supplier

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.