Zinsser Mold Killing Primer is a water based fungicidal protective coating that can be used to paint over all existing mold, mildew, moss, fungi, odor causing bacteria and any other fungal organisms. The Mold Killing Primer contains an EPA registered antimicrobial to prevent the growth of mold, mildew and other fungal organisms on the paint film. The Mold Killing Primer also aides in covering residual microbiological and fungal stains. Features Paint directly over mold Kills existing mold, mildew, and odor causing bacteria Binds chalky siding, masonry, and metal EPA Registered Interior / Exterior Water-based For stains caused by water leaks, allow Mold Killing Primer to dry then use a Zinsser stain blocking primer