PEG-6 Undecylenate

INCI: PEG-6 Undecylenate | Function: Surfactant, Emulsifier, Antimicrobial | Type: PEG Ester

What Is PEG-6 Undecylenate?

PEG-6 Undecylenate is a polyethylene glycol (PEG) ester of undecylenic acid (a fatty acid derived from castor oil). PEG-6 means it contains 6 ethylene oxide units, making it moderately water-soluble. Undecylenic acid is known for its antifungal and antimicrobial properties, making this ingredient useful in anti-dandruff shampoos, acne cleansers, and preservation systems.

Key Skin Benefits

+ Provides gentle cleansing — PEG ester surfactants are milder than SLS/SLES
+ Antimicrobial — undecylenic acid component inhibits fungal and bacterial growth
+ Emulsifying — helps oil and water phases combine in formulations
+ Anti-dandruff — commonly used in scalp care products

Pros

+ Gentle, non-stripping surfactant suitable for sensitive skin
+ Provides antimicrobial benefits without harsh preservatives
+ Biodegradable — PEG esters break down in the environment
+ Castor oil derived — renewable feedstock

Cons

− May contain trace 1,4-dioxane if not purified (regulated in EU)
− PEG compounds can enhance skin penetration of other ingredients
− Limited use in leave-on products due to surfactant properties

Specifications

Property	Value
Usage Areas	Face, Body, Hair
Product Type	Rinse-Off
Source	Semi-synthetic
Natural Level	Semi-synthetic

Safety Ratings

Metric	Rating
Skin Sensitivity	1/5
Comedogenic Rating	0/5
EWG Score	3/10

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 %
Anti-dandruff shampoo	0.5 - 2%
Facial cleanser	0.5 - 3%
Body wash	1 - 5%

References

CIR (2010) — Safety Assessment of PEGs as Used in Cosmetics. PMID: 20629512
CosIng (2025) — European Commission Cosmetic Ingredient Database. https://ec.europa.eu/growth/tools-databases/cosing/
EWG Skin Deep — PEG-6 Undecylenate safety profile. https://www.ewg.org/skindeep/
SpecialChem — PEG-6 Undecylenate cosmetic ingredient guide. https://cosmetics.specialchem.com/

← Back to Skinpedia