We use a non-toxic, non-corrosive chemical cleaning method. This is a professional grade oxidative cleaner designed for outdoor cleaning and pressure washing applications. It is a highly concentrated granular formula designed to quickly remove stains on common outdoor surfaces. It is safe to use on patio furniture, wooden & composite decking, awnings, umbrellas, covers, sidewalks, roofs, tile floors, grout, garage floors, stucco and vinyl siding, outdoor equipment, boats and more.