Sodium Tripolyphosphate STPP


SKU: RD11220

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Technical grade

Sodium tripolyphosphate (STPP) with formula Na5P3O10, is the sodium salt of triphosphoric acid. It is a water soluble, white, odourless powder or granules 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, softening, lead control, red and black water control.


Uses for sodium tripolyphosphate

It is used 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

Properties of sodium tripolyphosphate: 

  • 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)

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

PLEASE NOTE: This product is not for human or animal consumption.


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