Fast acting and CHLORINE free, this powerful nontoxic formula cleans the tough jobs yet is safe to use outdoors. Won’t harm plants, people or pets and breaks down quickly into natural components after use. Traditionally, products that use chlorine bleach, oxalic acid, petroleum solvents and phosphates have been used to do the cleaning and stain removal. While these products can be effective, they also can be very harmful to the environment, plants, grass, flowers and humans. 2.5 Pounds cleans a surface between 375 and 625 square feet depending on amount of vertical surface and extent of soil to be removed.