Sodium orthophosphates (Sodium phosphates, sodium phosphate, monosodium phosphate, disodium phosphate, trisodium phosphate, sodium orthophosphate, single-substituted sodium orthophosphate, double-substituted sodium orthophosphate, tri-substituted sodium orthophosphate, sodium tripolyphosphate, E339) are sodium salts of orthophosphoric acid.
The chemical formula is Na3PO4.
Types of sodium orthophosphates (sodium phosphates):
- (i) Monosodium phosphate, monosodium phosphate);
- (ii) Sodium orthophosphate, disodium phosphate);
- (iii) Sodium orthophosphate tri-substituted (trisodium phosphate).
Sodium phosphate is used in detergents, such as washing powder. Recently, the use of sodium phosphate in washing powders is prohibited in many countries to reduce the eutrophication of water bodies.
In smaller quantities, it is used in food products as a food additive E339.