Enviro Klean® Safety Klean is an effective, safe alternative to acidic compounds for cleaning brick, tile and concrete surfaces. Safety Klean rids new masonry construction of excess mortar, dirt and other common job site soiling. It’s ideal for projects where traditional acidic cleaners are not allowed. Non-fuming Safety Klean contains no hydrochloric or other traditional inorganic acids and is safe for use on and around most metal surfaces, indoors or out. It is up to 70 percent more effective than citric and glycolic acids, and 50 percent more effective than phosphoric acid.