C26-28 Alkyldimethylsilyl Polypropylsilsesquioxane

AKA: Silicone Resin

Synthetic

Occlusive

Silicone

Not Clean

C26-28 Alkyldimethylsilyl Polypropylsilsesquioxane is a cosmetic ingredient used as film forming, viscosity controlling. 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.

Viscosity Controlling

Creates Protective Barrier

Controls Viscosity

Creates protective layer

Controls product thickness

Traditional Use

A complex silicone-based polymer developed in the late 20th century for advanced cosmetics. Used as a texturizing and suspending agent in sophisticated skincare and makeup.

EWG

CIR

Safe as used

Pregnancy

Yes

CIR Safety Findings

Not a Sensitizer

medical-approval

all-shades-safe

Regulatory Status

USA✔ permitted

EU⚠ restricted

JAPAN⚠ restricted

CANADA⚠ restricted

Regulatory Agencies

EWG CIR FDA EU COSING Health Canada

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