This “readily” biodegradable product is the strongest of the Clean Green products. Concentrated cleaner for hard surfaces and oil residues. Can be used to clean and degrease any hard surface. Metal, Concrete, Walls, Floors, Equipment etc. Made with “readily biodegradable” surfactants that comply with the epa guidelines. The use pH range for Clear Choice Bio Kleen is 11-5 to 12.0.