This concrete cleaner has a powerful bleach-based formula that acts as a mold and mildew killer as it cleans and brightens your home's driveway. For use as a concrete and brick cleaner; also good for cleaning PVC, plastic, siding, masonry gutters, driveways. To use this concrete stain remover as a mold remover, apply full strength with a plastic garden sprayer. Wait 10 minutes, then thoroughly rinse off surface and surrounding area. Keep out of reach of children and follow all directions carefully.