Steareth-5
AKA “15-Pentaoxatritriacontan-1-ol, Pentaethylene glycol octadecyl ether”
Surfactant
Ingredient Facts
Steareth-5
AKA: 15-Pentaoxatritriacontan-1-ol, Pentaethylene glycol octadecyl ether
Surfactant · Cleansing · EWG: 4
Plant-Derived
Cleanser
Emulsifier
Plant Oil
Not Clean
Poly(oxy-1,2-ethanediyl), .alpha.-octadecyl-.omega.-hydroxy
Effective at 11.51%
CAS #
9005-00-9, 71093-13-5
See origin →
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
Nonionic surfactant synthesized through ethoxylation of stearic acid, created in the 1950s for cosmetic applications. Designed to improve stability and emulsification in lotions and creams.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
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%
Effective Range
CIR reported use: 18-23 | 0.02-0.4 | 0.2-1
Regulatory Agencies
Acrylates/Steareth-50 Acrylate Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isosteareth-5
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isosteareth-50
European Commission
EU Cosmetic Ingredient Database (CosIng)
Steareth-5
European Commission
EU Cosmetic Ingredient Database (CosIng)
Steareth-50
European Commission
EU Cosmetic Ingredient Database (CosIng)
Verified Jun 2026
Data: CosIng · EWG · CIR