murphyUndeceth-40
molecular structure · PubChem
AKA: Undecyl Polyethylene Glycol Ether, PEG Undeceth
Synthetic
Cleanser
Emulsifier
Skin Conditioner
Not Clean
OriginDerived from fatty alcohols, typically produced through the ethoxylation of undecyl alcohol or similar long-chain alcohols. Synthesized by adding ethylene oxide units to the fatty alcohol backbone through catalytic ethoxylation reactions.
Undeceth-40 is a cosmetic ingredient used as emulsion stabilising, skin conditioning, surfactant - cleansing. Assessed as safe by the CIR.
CAS #
127036-24-2
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Functions
Emulsion Stabilising
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
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.
Verified Jun 2026
Data: CosIng · EWG · CIR