Disclosed herein is a composition comprising a non-dusting copper pyrithione dispersion comprising small solid particles of copper pyrithione dispersed in a liquid dispersant, said solid particles having a particle size within a range of from about 0.1 to about 10 microns and a median particle size of from 0.2 to less than 0.5 microns. The dispersion is suitably employed as an antifouling additive for marine paints without risking worker exposure to copper pyrithione dust. Paints containing the small particle copper pyrithione exhibit improved antifouling performance in cold water, as compared to paint containing larger particle copper pyrithione.