Tridecyl Stearate

AKA: Octadecanoic acid, Tridecyl ester, LIPONATE TDS, ETHOX TDS, UNIFLEX 188
Plant-Derived
Emollient
Skin Conditioner
Clean
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
C31H62O2
Mol. Weight
466.80
CAS #
31556-45-3
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 ester created as a modern cosmetic ingredient to provide emollient properties and improve skin conditioning and product texture in cosmetic formulations.
EWG
1
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
Dryness
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing
🛡️Safety-assessed3 reviews
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR