C30-45 Alkyldimethylsilyl Polypropylsilsesquioxane

AKA: Silicone Resin
Synthetic
Occlusive
Silicone
Not Clean
C30-45 Alkyldimethylsilyl Polypropylsilsesquioxane is a cosmetic ingredient used as film forming. Assessed as safe by the CIR.
CAS #
-
Form
Powder
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
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.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing
🛡️Safety-assessed1 review
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: CosIng · EWG · CIR