CLR Calcium, lime and rust remover is a powerful formula that quickly and easily dissolves and removes tough calcium and lime deposits as well as surface rust stains from bathtubs, toilet bowls, sinks, glass, chrome, fiberglass, stainless steel, most coffee makers, humidifiers, dishwashers, washing machines and showerheads. The formula also is ideal for use on RVs and boats. CLR calcium, lime and rust remover is part of the EPA's safer choice program and contains no phosphates and is septic-safe.