Oleth-40
AKA “Oleyl Ethoxylate 40, Oleth 40, Polyethylene Glycol Monooleyl Ether”
Synthetic
Ingredient Facts
Oleth-40
AKA: Oleyl Ethoxylate 40, Oleth 40, Polyethylene Glycol Monooleyl Ether
Synthetic · Cleansing · EWG: 3
Synthetic
Cleanser
Emulsifier
Synthetic
Clean
A gentle cleansing agent that helps remove oil and impurities while keeping formulas stable and smooth-textured.
Effective at 9.03%
CAS #
9004-98-2
Form
Liquid
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.
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.
Removes Impurities
Cleansing Surfactant
Emulsifier
Mixes Oil & Water
Traditional Use
Synthetic surfactant and emulsifier developed in the mid-20th century by ethoxylating oleyl alcohol. These polyethylene glycol derivatives were created to provide stable emulsification and solubilization properties in cosmetics and pharmaceuticals.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
3
CIR
Safe w/Qualifications
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.06%
18.0%
0%25%
Effective Range
CIR reported use: 0.1-18 | 0.3-10 | 1-4 | 0.06-10
Regulatory Agencies
Verified Feb 2026
Data: CosIng · EWG · CIR