White, Zinsser Mold Killing Primer-316097, Quart: Specially made with a fungicidal protective design that can be used to paint directly over all existing bacteria on walls, gutters, and other surfaces. It works potently against mold, mildew, moss, fungi, odor-causing germs and more. The antimicrobial formula of the Zinsser primer prevents the growth of fungal organisms on the paint film and aids in covering residual microbiological and fungal stains. This water-based product binds onto chalky siding, masonry and metal.