Sodium tripolyphosphate

A white, powdery inorganic compound, the sodium salt of the polyphosphate penta-anion. It is manufactured for use as an emulsifier and chelating agent in water softeners and detergents. In conservation it has been used as a sequestering agent for the treatment of excavated copper and bronze objects, a chelating agent in the conservation of paper objects, and as a surfactant in the cleaning of photographs. It has been suspected of contributing to water pollution.