What it is
Polyacrylic Acid is a water-soluble polymer of acrylic acid that swells and thickens when neutralized in water-based systems. In sunscreens it is used to build viscosity, suspend pigments or filters, and give the formula a stable, uniform consistency. It can also help form a smooth film on application that improves the spread and feel of the product.
Safety & warnings
Polyacrylic acid polymers are large molecules that remain on the skin surface and are generally non-irritating and well tolerated at cosmetic use levels.
Origin & sourcing
Synthetic. It is produced by polymerizing acrylic acid monomers.
Questions everyone asks
What does Polyacrylic Acid do in sunscreen?
It thickens the formula and helps keep ingredients evenly suspended, giving the product a stable, smooth texture.
Is Polyacrylic Acid the same as carbomer?
It is closely related. Carbomers are crosslinked acrylic acid polymers, while polyacrylic acid is the broader acrylic acid polymer family used for similar thickening purposes.