Powdered Brewery Wash is an alkaline, non-caustic, environmentally and user friendly cleaner. This is the tablet product. 

PBW is a buffered alkaline detergent that has been proven to be more than an effective substitute for caustic soda cleaners. Because of its unique formulation of buffers and mild alkalis, it is safe on skin as well as soft metals such as stainless steel, aluminum, and on plastics. P.B.W. uses active oxygen to penetrate carbon or protein soils and is not effected by hard water.