Sodium pyrophosphate, Na4P2O7, is a moisture-absorbing white crystalline powder that dissolves in water but not in organic solvents. It functions as a chelating agent for metal ions, such as copper in electroplating solutions, and as a rust remover in mechanical processing. It is also utilized as a stabilizer for hydrogen peroxide and as a bleaching aid and wool degreasing agent when combined with sodium hydrosulfite. In water treatment, it is used as a water softener and boiler descaling agent. In toothpaste production, it stabilizes the colloid formed when calcium hydrogen phosphate is used. Sodium pyrophosphate also serves as a dispersant, emulsifier, deflocculant, and quality improver in chemical and food production. Lastly, it is a precursor to other types of pyrophosphates.
