Home Armor Mildew stain remover plus blocker is a powerful bleach-free cleaning formula. Cleans mold, mildew, soap scum, and mineral deposits like calcium and lime. Anti-spore barrier prevents mold from coming back for 3 months. Use it on counters, sinks, shower curtains, tubs, shower doors, toilets, outdoor furniture, doors, ceilings, and anywhere mold is a problem. Mildew stain remover plus blocker is safe to use indoors and outdoors on aluminum, glass, fiberglass, stone (except natural marble), cultured marble, acrylic PVC, vinyl, porcelain, rubber, chrome, plastic, formica, and more. It's long-term blocker effectiveness is not diminished by rain or repeated washings. It is a stain remover but not a bleach product. The barrier left behind will make the clean last longer.