C30-45 Alkyldimethylsilyl Polypropylsilsesquioxane
AKA “Silicone Resin, Polypropylsilsesquioxane
Synthetic
Ingredient Facts
C30-45 alkyldimethylsilyl polypropylsilsesquioxane
AKA: Silicone Resin
Synthetic · Emollient · EWG: 4
Synthetic
Emollient
Occlusive
Skin Conditioner
Silicone
Synthetic
Clean
Science: Functions: Film Forming Safety Ratings: CIR: Safe as used
CAS #
-
Form
Powder
See origin →
Functions
Film Forming
Creates a physical seal on skin to lock moisture in and keep irritants out. The "slugging" ingredient — barrier protection.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Emollient
Fills in the tiny cracks between skin cells to make everything feel smooth and soft. The "silky finish" ingredient.
Creates Protective Barrier
Traditional Use
A modern silicone polymer developed for the cosmetics industry in the late 20th century to provide enhanced conditioning, smoothing, and anti-stick properties in makeup and skincare products.
Skin Types
all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Verified Feb 2026
Data: CosIng · EWG · CIR