Octoxynol-9 Carboxylic Acid

Octoxynol-9 Carboxylic Acid molecular structure
molecular structure · PubChem
AKA: 3, 6, 12, 15, 18, 21, 24-Octaoxahexacosanoic acid, PEG-9 Octyl phenyl ether carboxylic acid, 25338-58-3, 2-[2-[2-[2-[2-[2-[2-[2-[2-(2-octylphenoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]acetic acid, 26-(Octylphenoxy)-3, 24-octaoxahexacosanoic acid, 26-(2-OCTYLPHENOXY)-3, 24-OCTAOXAHEXACOSANOIC ACID, 26-(2-octylphenoxy)-3, 24-octaoxahexacosan-1-oic acid
Synthetic
Cleanser
Acid
Not Clean
26-(Octylphenoxy)-3,6,9,12,15,18,21,24-octaoxahexacosanoic acid
Formula
C32H56O11
Mol. Weight
616.80
CAS #
25338-58-3
Form
Liquid
State
Solid
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Cleansing Surfactant
Antioxidant Protection
Reduces Inflammation
Locks In Moisture
Removes Impurities
Traditional Use
A derivative of octoxynol-9 created by introducing a carboxylic acid functional group. Used in cosmetics as an emulsifier with enhanced properties for specific formulation needs.
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
medical-approval
all-shades-safe
Mild Irritant
Regulatory Status
USA✔ permitted
EU⚠ restricted
JAPAN⚠ restricted
CANADA⚠ restricted
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing →
🛡️Safety-assessed3 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR