STPP is white powder, apparent density:0.35-0.90g/ml, melting point: 622°C, easily dissolving in water; water solution is alkaline(PH value of 1% solution is 9.7); can hydrolyze into phosphate in water, has good ability in complexing metal ions,; can be used to soften water; has some surfactant properties.1)In Detergents The majority of STPP is consumed as a component of commercial detergents. It serves as a "builder," industrial jargon for a water softener. In hard water (water that contains high concentrations of Mg2+ and Ca2+), detergents are deactivated. Being a highly chargedchelating agent, TPP5- binds to dications tightly and prevents them from interfering with the sulfonate detergent. 2)Food Applications STPP is a preservative for seafood, meats, poultry, and animal feeds.It is common in food production as E number E451. In foods, STPP is used as an emulsifier and to retain moisture. Many governments regulate the quantities allowed in foods, as it can substantially increase the sale weight of seafood in particular. The UnitedStates Food and Drug Administration lists STPP as "generally recognized as safe.". 3)Other Uses Other uses (hundreds of thousands of tons/year) include "ceramics, leather tanning(as masking agent and synthetic tanning agent - SYNTAN), anticaking, setting retarders, flame retardants, paper, anticorrosion pigments, textiles, rubber manufacture, fermentation, antifreeze.