Stearoxytrimethylsilane
AKA: Trimethyl(octadecyloxy)silane, 18748-98-6, Stearoxy trimethylsilane, Stearyloxytrimethylsilane, Stearoxy trimethyl silane, SILCARE SILICONE 1M71
Plant-Derived
Emollient
Skin Conditioner
Silicone
Clean
Trimethyl(octadecyloxy)silane
Formula
C21H46OSi
Mol. Weight
342.70
CAS #
18748-98-6
Form
Liquid
Functions
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.
Locks In Moisture
Traditional Use
Synthetic silicone derivative combining stearic acid with trimethylsilane chemistry, developed for cosmetic applications in the late 20th century. Used to provide water-repellent and conditioning properties.
Skin Types
●all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
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.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR