Isodeceth-4
molecular structure · PubChem
AKA: Isodecyl alcohol ethoxylate, PEG-4 isodecyl ether
Synthetic
Cleanser
Emulsifier
Not Clean
Alcohols, C10-branched, ethoxylated (4 mol EO average molar ratio)
Effective at 1.6%
CAS #
9002-92-0; 68439-50-9; 5274-68-0; 9004-95-9; 9005-00-9; 4536-30-5; 3055-93-4; 3055-94-5; 3055-95-6
Form
Liquid
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Cleansing Surfactant
Emulsifier
Removes Impurities
Mixes Oil & Water
Traditional Use
Synthetic ethoxylated surfactant developed in the 20th century for use as a solubilizer and emulsifier in modern cosmetic formulations with no traditional use.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.2%
3.0%
0%4%
Reported use
CIR reported use: 0.7-2 | 1-3 | 0.2-3
Regulatory Agencies
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
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