Oleth-9
AKA “Oleyl Ethoxylate 9, Oleth 9, Polyethylene Glycol Monooleyl Ether”
Synthetic
Ingredient Facts
Oleth-9
AKA: Oleyl Ethoxylate 9, Oleth 9, Polyethylene Glycol Monooleyl Ether
Synthetic · Cleansing · EWG: 3
Synthetic
Cleanser
Emulsifier
Synthetic
Clean
A gentle emulsifier that helps blend water and oil-based ingredients together, creating a smooth, stable texture that feels comfortable on skin.
Effective at 9.03%
CAS #
9004-98-2
Form
Liquid
See origin →
Functions
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifier
Mixes Oil & Water
Traditional Use
Developed in the mid-20th century as a synthetic polyethylene glycol ether derivative of oleic acid. Used in cosmetics as a surfactant and emulsifier with no significant traditional use history.
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