Trisodium phosphate (TSP) is an inorganic compound with the chemical formula Na3PO4. It is a white, granular or crystalline solid, highly soluble in water, producing an alkaline solution. TSP is used as a cleaning agent, builder, lubricant, food additive, stain remover, and degreaser.
As an item of commerce TSP is often partially hydrated and may range from anhydrous Na3PO4 to the dodecahydrate Na3PO4·12H2O. Most often it is found in white powder form. It can also be called trisodium orthophosphate or simply sodium phosphate.