Sodium Algin Sulfate
AKA “Sulfated Alginate, Marine Polymer”
Humectant
Ingredient Facts
Sodium algin sulfate
AKA: Sulfated Alginate, Marine Polymer
Humectant · Humectant · EWG: 4
Synthetic
Humectant
Marine
Medicated Active
Not Clean
Sodium Algin Sulfate is the sulfate ester of Algin (q.v.)
CAS #
9010-06-4
Form
Powder
See origin →
Functions
Humectant
A moisture magnet. Pulls water from the air and deeper skin layers up to the surface to keep skin plump and hydrated.
Locks In Moisture
Traditional Use
Derived from brown seaweed, algin has been used in traditional Japanese and Chinese skincare for centuries for its moisture-binding and skin-soothing properties. The sodium salt form was developed in the 20th century for improved cosmetic stability.
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 Agencies
Verified Jun 2026
Data: CosIng · EWG · CIR