Due to its low solubility in water (8 ppm at neutral pH), zinc pyrithione is suitable for use in outdoor paints and other products that provide protection against mildew and algae . It is an effective algaecide . It is chemically incompatible with paints relying on metal carboxylate curing agents. When used in latex paints with water containing high amount of iron , a sequestering agent that will preferentially bind the iron ions is needed. Its decomposition by ultraviolet light is slow, providing years of protection even against direct sunlight.