Sodium tripolyphosphate (STPP) is a sodium salt of triphosphoric acid . It is used in various applications such as a preservative for seafood, meats, poultry and pet foods. It is also used in toothpaste and as a builder in soaps and detergents, improving their cleansing ability.

The United States Food and Drug Administration lists STPP as "generally recognized as safe", along with salt, vinegar, baking powder, and monosodium glutamate. An excessive amount of STPP in food brings the disadvantage for consumers that products sold by the pound contain more water than products without STPP.