High concernOther
Perfluorohexyl Triethoxysilane
PFASEnvironmental persistence
What it is
A short-chain perfluoroalkyl silane, a PFAS used as a surface modifier.
What it does
Provides long-wear, water-resistant properties in cosmetics and coatings.
Why it’s a concern
Short-chain PFAS can be environmentally persistent and mobile. Faster serum clearance does not establish safety, environmental breakdown, or a low total risk. Human disease evidence for many short-chain replacements remains sparse. Product testing and laboratory skin models show possible cosmetic exposure, but normal-use uptake and health risk have not been quantified.
Also known as
C6-PFAS silane
CAS numbers
85857-16-5
Commonly found in
long-wear foundationwaterproof makeup
Safer alternatives
- silicone-free long-wear formulas with plant-based resins
Related chemical families
Sources
- ECHA PFAS Restriction Proposal 2023