Polypropylsilsesquioxane

Synthetic
Occlusive
Clean
OriginSynthesized from silicone polymers, specifically through hydrolysis and condensation of silane precursors containing propyl groups. Created via sol-gel polymerization methods that crosslink silicon-oxygen frameworks into a three-dimensional silsesquioxane network structure.
Polymer formed by hydrolysis and condensation of propyltrichlorosilane
CAS #
36088-62-7
Form
Powder
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Functions
Film Forming
Creates a physical seal on skin to lock moisture in and keep irritants out. The "slugging" ingredient — barrier protection.
Creates Protective Barrier
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
1
CIR
Safe as used
Pregnancy
Yes
Concentration Guide
Leave-on0.8–2.4%
Rinse-offNot reported
0%50%100%
CIR reported use · report published 2017
Regulatory Status
USA✔ permitted
EU⚠ restricted
JAPAN⚠ restricted
CANADA⚠ restricted
Verified Jun 2026
Data: CosIng · EWG · CIR