A method for producing a suspension, emulsion or dispersion of de-agglomerated particles (advantageously submicron-sized particles) of pyrithione salts comprising contacting agglomerated pyrithione salt particles with a de-agglomerating agent to produce the desired de-agglomerated pyrithione salt particles. Also disclosed is a method for making de-agglomerated submicron-sized particles of pyrithione salts comprising a heating step. Also disclosed are the particles made by the above methods and compositions comprising the particles and a base medium.