Oleth-5
AKA: Oleyl Ethoxylate 5, Oleth 5, Polyethylene Glycol Monooleyl Ether
Synthetic
Cleanser
Emulsifier
Clean
Poly(oxy-1,2-ethanediyl), .alpha.-9-(Z)-octadecenyl-.omega.-hydroxy (5 mol EO average molar ratio)
Effective at 9.03%
CAS #
9004-98-2
Form
Liquid
Functions
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Emulsifier
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.
EWG
2
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.06%
18.0%
0%25%
Reported use
CIR reported use: 0.1-18 | 0.3-10 | 1-4 | 0.06-10
Regulatory Agencies
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed3 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: CosIng · EWG · CIR