Potassium Undecylenoyl Alginate
AKA “Alginate Surfactant
Skin Conditioning
Ingredient Facts
Potassium undecylenoyl alginate
AKA: Alginate Surfactant
Skin Conditioning · Emulsion Stabilising · EWG: 4
Synthetic
Emulsifier
Skin Conditioner
Hair Care
Marine
Not Clean
Alginic acid, reaction products with 10-undecenoyl chloride, potassium salts
CAS #
224580-88-5
Form
Powder
See origin →
Functions
Emulsion Stabilising
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Hair Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Locks in moisture
Traditional Use
A modern synthetic derivative combining undecylenic acid (from castor oil) with sodium alginate (from seaweed) developed in the late 20th century. It was engineered to combine the antimicrobial benefits of undecylenic acid with the film-forming and thickening properties of alginate.
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Concentration Guide
Dermal absorption: 2%. Source: CIR Safety Assessment (CIR Seq 680).
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Verified Jun 2026
Data: CosIng · EWG · CIR