A PEG-8 sesquiester of oleic acid, an omega-9 monounsaturated fatty acid found in olive oil, avocado oil, and many other plant oils. The oleic acid backbone provides emolliency and skin-penetrating properties, while the PEG-8 chain renders the molecule water-dispersible. It functions as an O/W emulsifier and co-emulsifier with conditioning benefits.
+ Oleic acid emolliency — provides skin-softening and conditioning
+ Enhances penetration — oleic acid is known to improve delivery of other active ingredients
Pros
+ CIR-reviewed — PEG oleates considered safe in cosmetics
+ Plant-derived — oleic acid sourced from olive, avocado, and other vegetable oils
+ Non-comedogenic
+ Penetration-enhancing properties — useful in treatment serums
+ Good skin feel — leaves a soft, conditioned finish
Cons
− PEG content — ethoxylation impurity concerns
− Oleic acid may be slightly comedogenic in its pure form — but PEG esterification mitigates this
− Limited individual safety data
Specifications
Property
Value
Usage Areas
Face, Eye, Body
Product Type
Leave-On, Rinse-Off
Source
Semi-synthetic
Natural Level
Semi-synthetic
Safety Ratings
Metric
Rating
Skin Sensitivity
1/5 (very low)
Comedogenic Rating
0/5
EWG Score
1/10
Regional Regulatory Limits
Region
Leave-on %
Rinse-off %
Status
EU (CosIng)
No limit
No limit
Allowed
US (CIR/FDA)
No limit
No limit
Allowed
Japan (MHLW)
No limit
No limit
Allowed
ASEAN
No limit
No limit
Allowed
China (NMPA)
No limit
No limit
Allowed
Typical Usage % by Product Type
Product Type
Typical %
Treatment creams
1-5%
Serum-emulsions
0.5-3%
References
CIR (Cosmetic Ingredient Review) — Safety Assessment of PEG and PEG Derivatives as Used in Cosmetics. Published in International Journal of Toxicology.
CosIng (2025) — European Commission Cosmetic Ingredient Database. https://ec.europa.eu/growth/tools-databases/cosing/
EWG Skin Deep — Cosmetic Ingredient Hazard Score. https://www.ewg.org/skindeep/
Personal Care Products Council (PCPC) — INCI Monograph and Safety Data.