Ceteth-40
molecular structure · PubChem
AKA: Polyethylene glycol cetyl ether, PEG-40 cetyl ether, Cetyl polyethylene glycol ether
Synthetic
Cleanser
Not Clean
Poly(oxy-1,2-ethanediyl), .alpha.-hexadecyl-.omega.-hydroxy- (40 mol EO average molar ratio)
Effective at 10.5%
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.
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Removes Impurities
Cleansing Surfactant
Traditional Use
Developed in the mid-20th century as a polyethylene glycol ether of cetyl alcohol. Created to replace traditional animal-derived emulsifiers and surfactants in cosmetics and pharmaceuticals.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.0002%
21.0%
0%29%
Reported use
CIR reported use: 0.0002-21 | 0.0002-8 | 0.2-3 | 0.2-4
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