Steareth-40
AKA: Polyethylene glycol stearyl ether, PEG-40 Stearate
Plant-Derived
Cleanser
Plant Oil
Not Clean
Poly(oxy-1,2-ethanediyl), .alpha.-octadecyl-.omega.-hydroxy
Effective at 11.51%
CAS #
9005-00-9
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Gel Forming
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
Removes dirt and impurities
Lifts away dirt and oil
Creates gel consistency
Traditional Use
Synthetic nonionic surfactant produced by ethoxylating stearic acid, developed for the cosmetics industry in the mid-20th century. Used as a reliable emulsifier and solubilizer in modern skincare products.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.02%
23.0%
0%32%
Reported use
CIR reported use: 18-23 | 0.02-0.4 | 0.2-1
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