DampRid Mold Blocker creates an invisible barrier to the growth of mold and mildew. Mold Blocker provides protection from mold and mildew staining when properly applied. Mold Blocker establishes a barrier between most household non-porous surfaces and bacteria and mold and mildew that cause odor, staining and discoloration. It"s a water-resistant anti-microbial and odor-free product that provides protection indoors and out. It works continuously for up to 3 months. Use it indoors and out - its effectiveness can"t be diminished by repeated washings or rain. It"s ideal for use on: glazed tiles, grout, shower curtains, tubs, garbage cans, deck furniture, bedding, apparel, upholstery, carpets, vinyl.