Smith" s Cleaner & Toughener " CT-8" is a dual purpose product designed for the preparation of exterior textured concrete surfaces to receive Smith" s Decorative Concrete Products including Smith's Color Floor., Color Wall and Color Accents, Initially, CT-8 acts as a detergent to clean the concrete surface. Secondly, CT-8 toughens the surface of the concrete by interacting with weak spots created by un-reacted calcium hydroxide. CT-8 is biodegradable but should not be discharged as a powder or an undiluted cleaning solution directly into streams, ponds, lakes, etc.