Butyl Stearate
AKA “Butyl octadecanoate, N-Butyl stearate, Octadecanoic acid, butyl ester, Kesscoflex BS, Kessco BSC, n-Butyl octadecanoate, Butyl octadecylate”
Synthetic
Ingredient Facts
Butyl stearate
AKA: Butyl octadecanoate, N-Butyl stearate, Octadecanoic acid, Butyl ester, Kesscoflex BS, Kessco BSC, N-Butyl octadecanoate, Butyl octadecylate
Synthetic · Emollient · EWG: 1
Plant-Derived Synthetic
Emollient
Skin Conditioner
Synthetic
Clean
A lightweight emollient that softens and conditions skin, leaving it smooth and supple without feeling greasy.
Effective at 21.5%
Solubility Insoluble in water; soluble in ethanol; very soluble in acetone
Formula
C22H44O2
Mol. Weight
340.60
CAS #
123-95-5
Form
Liquid
See origin →
Functions
Emollient
Fills in the tiny cracks between skin cells to make everything feel smooth and soft. The "silky finish" ingredient.
Viscosity Controlling
Locks In Moisture
Traditional Use
Synthetic ester developed as a cosmetic emollient and conditioning agent. Created to provide texture improvement and skin compatibility in skincare and color cosmetic formulations.
Skin Types
●all-skin-types, gentle
Best For
Dryness
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
1
CIR
Safe
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
ewg-1
medical-approval
pregnancy-nursing-safe
all-shades-safe
Concentration Guide
0.0008%
43.0%
0%60%
Effective Range
CIR reported use: 0.0008-12 | 0.002-43
Regulatory Agencies
Final Report on the Safety Assessment of Butyl Stearate, Cetyl Stearate, Isobutyl Stearate, Isocetyl Stearate, Isopropyl Stearate, Myristyl Stearate, and Octyl Stearate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Ethyl Ester of PVM/MA Copolymer and Butyl Ester of PVM/MA Copolymer
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Butyl Ester of PVM/MA Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Butyl Stearate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isobutyl Stearate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Potassium Butyl Ester of PVM/MA Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Butyl Ester of PVM/MA Copolymer
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Butyl Stearate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Isobutyl Stearate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR