Tri Sodium Phosphate
Trisodium phosphate (TSP) is the 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.
The item of commerce is often partially hydrated and may range from anhydrous Na3PO4 to the dodecahydrate Na3PO4 · 12H2O. Most often found in white powder form, it can also be called trisodium orthophosphate or simply sodium phosphate.
Molar mass: 163.94 g/mol
Gibbs free energy (ΔfGËš): -1819 kJ/mol (anhydrous)
Basicity (pKb): 2.23
Heat capacity (C): 665 J/mol·K (dodecahydrate)
GHS hazard statements: H315, H318, H335
Trisodium phosphate was at one time extensively used in formulations for a variety of consumer-grade soaps and detergents, and the most common use for trisodium phosphate has been in cleaning agents. The pH of a 1% solution is 12 (i.e., very basic), and the solution is sufficiently alkaline to saponify grease and oils. In combination with surfactants, TSP is an excellent agent for cleaning everything from laundry to concrete driveways.
TSP is commonly used after cleaning a surface with mineral spirits to remove hydrocarbon residues and may be used with household chlorine bleach in the same solution without hazardous reactions. This mixture is particularly effective for removing mildew, but is less effective at removing mold.
Although it is still the active ingredient in some toilet bowl-cleaning tablets, TSP is generally not recommended for cleaning bathrooms because it can stain metal fixtures and can damage grout.