Sodium Undecylenate
AKA “Sodium undec-10-enoate, Undecylenic Acid Sodium Salt, UNII-V50TG7E11W, 10-Undecenoic acid, sodium salt, EINECS 222-264-8, AI3-19721”
Synthetic
Ingredient Facts
Sodium undecylenate
AKA: Sodium undec-10-enoate, Undecylenic Acid Sodium Salt, UNII-V50TG7E11W, 10-Undecenoic acid, Sodium salt, EINECS 222-264-8, AI3-19721
Synthetic · Cleansing · EWG: 4
Synthetic
Preservative
Cleanser
Emulsifier
Synthetic
Clean
A gentle preservative that keeps products fresh while helping cleanse and blend ingredients smoothly together.
Formula
C11H19NaO2
Mol. Weight
206.26
CAS #
3398-33-2
State
Solid; [Sigma-Aldrich MSDS]
See origin →
Functions
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Surfactant Cleansing
Surfactant Emulsifying
Anti-Inflammatory
Antimicrobial
Fights Acne
Lifts away dirt and oil
Prevents microbial growth
Mixes oil and water
Traditional Use
Undecylenic acid was derived from castor oil in the early 20th century and traditionally used as an antifungal agent in folk medicine. The sodium salt form was developed to improve solubility and stability in modern skincare and antifungal products.
Skin Types
●all-skin-types
Best For
Acne
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
0.2%
0%0%
Reg. Limit
EU regulatory limit: 0.2%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 18.
Regulatory Agencies
Effects of Sodium Salts of Fatty Acids and Their Derivatives on Skin Permeation of Cromolyn Sodium.
Akinbote OE, Verana G, Dandekar AA, Tijani AO, Mishra D et al.
AAPS PharmSciTech, 2023
Effects of Sodium Salts of Fatty Acids and Their Derivatives on Skin Permeation of Cromolyn Sodium.
Akinbote OE, Verana G, Dandekar AA, Tijani AO, Mishra D et al.
AAPS PharmSciTech, 2023
RIFM fragrance ingredient safety assessment, 10-undecenoic acid, heptyl ester, CAS Registry Number 68141-27-5.
Api AM, Belsito D, Botelho D, Bruze M, Burton GA Jr et al.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2018
Sodium Undecylenate
European Commission
EU Cosmetic Ingredient Database (CosIng)
SODIUM SALT
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR