Sodium trimetaphosphate

Sodium Trimetaphosphate (STMP, CAS 7785-84-4) is an inorganic phosphate salt also known as Trisodium Trimetaphosphate, Sodium Metaphosphate, or (NaPO3)3. It is not assigned an E-number and is commercially identified under EC 232-088-3. Its cyclic triphosphate ring structure distinguishes it from linear polyphosphates.

In water treatment, STMP sequesters calcium and magnesium ions by forming stable chelate complexes, preventing scale formation in pipework and boilers. In food and textile processing, it functions as a crosslinking agent for starches and a dispersant for dyes and pigments, improving uniformity and process efficiency through its ability to bind multivalent metal ions.

STMP is available as a technical-grade powder supplied in compliance with REACH regulations. Procurement quantities are typically offered in 25 kg bags or bulk formats. Buyers requiring food-contact applications should confirm FCC or equivalent food-grade certification with the supplier prior to ordering.