PEG-9 Stearamide Carboxylic Acid is an anionic surfactant derived from stearic acid, ethoxylated with 9 moles of ethylene oxide and carboxylated at the terminal end. The carboxylic acid group provides anionic character, making it a mild cleansing agent with good foaming properties. Used primarily in rinse-off products.
Key Skin Benefits
+ Mild cleansing — gentle on skin and scalp
+ Foam generation — produces stable, rich lather
+ Synthetic origin — consistent quality and performance
Pros
+ Milder than traditional anionic surfactants (SLS/SLES)
+ Good foam quality in hard water
+ Compatible with nonionic and amphoteric surfactants
Cons
− Synthetic — petroleum-derived
− Potential 1,4-dioxane trace contamination
− Moderate cost compared to commodity surfactants
Specifications
Property
Value
Usage Areas
Face, Body, Hair
Product Type
Rinse-Off
Source
Synthetic
Natural Level
Synthetic
Safety Ratings
Metric
Rating
Skin Sensitivity
1/5
Comedogenic Rating
0/5
EWG Score
2/10
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 %
Facial cleansers
1 - 5%
Shampoos
1 - 3%
Body washes
1 - 5%
References
CIR (2010) — Safety Assessment of PEGs. https://www.cir-safety.org/
CosIng (2025) — European Commission Cosmetic Ingredient Database. https://ec.europa.eu/growth/tools-databases/cosing/