Sodium/TEA-Undecylenoyl Alginate
AKA: Seaweed Extract
Plant-Derived
Emulsifier
Skin Conditioner
Hair Care
Marine
Not Clean
Alginic acid, 10-undecenoyl derivatives, sodium tris(2-hydroxyethyl)amine salts
CAS #
224580-93-2
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 ingredient combining undecylenic acid (from castor oil) with alginate (from seaweed) in salt form. Developed to provide antifungal and conditioning benefits while leveraging the traditional use of seaweed in skincare.
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 Agencies
Skin Types
●all-skin-types
Best For
Acne
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: CosIng · EWG · CIR