Safe for all types of plumbing, Roebic FRK-1LB Foaming Root Killer clears roots from pipes and stops new root growth. The exclusive product, which does not contain copper, foams on contact with water to fill the entire pipeline with the root killing agent dichlobenil to destroy roots that find their way into in a home's sewer line, which can cause costly backups. Foaming Root Killer is recommended for severe recurring root problems. To use, follow directions as listed for your application method, including for use in residential sewer lines, and between tree roots and sewer lines. Roebic FRK-1LB Foaming Root Killer is banned for use in septic systems in the state of Florida due to state regulations, and is not for sale outside the contiguous U.S. For over 50 years, Roebic has developed high quality products engineered for optimum performance, targeting specific problems and troublesome areas within the septic system. Trust Roebic, The Septic Professionals, for all your septic and drain care needs.