What it is
This is a high-molecular-weight crosspolymer built from sodium acrylate, acryloyldimethyltaurate, and dimethylacrylamide units that swells in water to form a clear, lightweight gel network. Formulators use it to thicken aqueous phases, stabilize oil-in-water emulsions, and give sunscreens a smooth, non-tacky slip without the soaping seen with some carbomers. It tolerates a relatively wide pH range and is compatible with many electrolytes, which suits it to gel-cream sun serums.
Safety & warnings
As a large, water-swellable polymer it is generally non-irritating and is not absorbed into skin, so it is well tolerated and considered non-comedogenic. Sensitization is uncommon.
Origin & sourcing
Synthetic, produced by free-radical polymerization of acrylic monomers.
Questions everyone asks
What does this crosspolymer do in a sunscreen?
It thickens the water phase and stabilizes the emulsion, giving the product a smooth gel texture and helping keep UV filters and pigments evenly suspended.
Is it the same as carbomer?
No. Both are acrylic thickeners, but this crosspolymer has a different monomer makeup, tolerates electrolytes and a broader pH range, and tends to give a less tacky feel.