Isodecyl Stearate

AKA: 31565-38-5, Octadecanoic acid, Isodecyl ester, STEARIC ACID, ISODECYL ESTER, ISODECYL STEARATE [INCI], 250-704-9, 8-methylnonyl octadecanoate
Plant-Derived
Emollient
Skin Conditioner
Not Clean
OriginDerived from fatty acids and stearyl alcohol, both typically sourced from animal or vegetable oils. Produced through esterification, where stearyl alcohol reacts with isodecanoic acid under catalytic conditions.
The CIR Expert Panel concluded that the alkyl esters, listed subsequently, are safe in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating.
Formula
C28H56O2
Mol. Weight
424.70
CAS #
31565-38-5
Form
Liquid
Skin Types
●all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
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
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.
EWG
4
CIR
Safe as used
Pregnancy
Yes
Concentration Guide
CIR lists it as not reported to be in use.
CIR · report published 2015
Regulatory Status
USA✔ permitted
EU⚠ restricted
JAPAN⚠ restricted
CANADA⚠ restricted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR