What is Sodium Tripolyphosphate and what is it used for


Sodium tripolyphosphate (STPP) with formula Na5P3O10, is the sodium salt of triphosphoric acid. It is a water soluble, white, odourless powder or granular material. STPP is most commonly used as a builder in detergent and cleaning formulations as it enhances their cleaning power. It also acts as a water softener. It acts as a Sequestrant for alkaline metals, scale control, corrosion control, and water softening.

  • CAS No: 7758–29–4
  • EINECS No: 231–838–7
  • Other Names: Sodium tripolyphosphate; STPP; STP; sodium triphosphate; TPP; Pentasodium triphosphate;
  • Appearance: White powder
  • Formula: Na5P3O10
  • Density: 2.52 g/cm3
  • Molar Mass: 367.86 g mol/1
  • Melting point: 622 oC
  • Solubility: soluble in water 145 g/L @25C
  • pH: 9.5 – 10.3 (10% solution)

Uses for sodium tripolyphosphate

It is used in various applications including in toothpaste and as a builder in soaps and detergents, improving their cleansing ability.

STPP is a solid inorganic compound used in a large variety of household cleaning products, mainly as a builder, but also in industrial cleaning processes and ceramics manufacture. STPP is widely used in regular and compact laundry detergents and automatic dishwashing detergents (in powder, liquid, gel and/or tablet form), toilet cleaners, surface cleaners, and coffee urn cleaners. It also provides a number of chemical functions including: sequestration of “water hardness”, enabling surfactants to function effectively; pH buffering; dirt emulsification and prevention of deposition; hydrolysis of grease; and dissolving-dispersing dirt particles


Health & Safety

R-phrase(s): R36/37/38 Irritating to eyes, respiratory system and skin.

S-phrase(s): S26 In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 Wear suitable protective clothing

For more information see MSDS for sodium tripolyphosphate


Where to buy Sodium tripolyphosphate online

Buy Sodium Sulphate

Buy Sodium Bisulphate

Buy Sodium Thiosulphate



About mistralhowto

formulation chemist

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