Sodium Tripolyphosphate (STPP), chemical formula Na₅P₃O₁₀, is a white crystalline inorganic compound with a wide range of industrial and commercial applications. It is produced by the controlled thermal condensation of mono- and di-sodium phosphates, and exists in two anhydrous phases (Form I and Form II) as well as a hexahydrate.
STPP is particularly valued for its ability to sequester divalent cations such as calcium (Ca²⁺) and magnesium (Mg²⁺), effectively softening water and preventing scale formation. In detergent formulations, it acts as a builder, improving surfactant performance by removing hardness minerals. In food processing, it is approved as food additive E451 for moisture retention and texture improvement.
Multi-sector versatility: STPP serves as a key functional ingredient in detergents, water treatment, ceramics, food processing, and industrial cleaning, making it one of the most commercially important phosphate compounds.
| Sector | Application | STPP Function |
|---|---|---|
| Detergent Industry | Laundry powders and liquid detergents | Builder, water softener, soil suspension |
| Water Treatment | Scale and corrosion inhibition in pipelines | Sequestrant, threshold inhibitor |
| Food Processing | Meat processing, seafood, dairy products | Moisture retention, pH buffer (E451) |
| Ceramics | Glaze preparation, clay slips, body mixes | Deflocculant, viscosity control |
| Paper Industry | Process water treatment, pulp dispersing | Dispersant, scale inhibitor |
| Textile Industry | Dyeing and scouring processes | Water conditioner, chelating agent |
| Parameter | Technical Grade | Food Grade (E451) |
|---|---|---|
| Assay (Na₅P₃O₁₀) | ≥ 85% | ≥ 95% |
| P₂O₅ content | 56 – 58% | 57 – 58% |
| pH (1% solution) | 9.5 – 10.5 | 9.5 – 10.2 |
| Appearance | White crystalline powder | White crystalline powder |
| Moisture content | ≤ 1.0% | ≤ 0.5% |
| Water insoluble matter | ≤ 0.2% | ≤ 0.1% |
| Bulk density | 0.6 – 0.9 g/cm³ | 0.6 – 0.9 g/cm³ |
| Packaging | 25 kg HDPE bags, 50 kg woven bags | |
Contact us for technical grade, food grade, or detergent grade STPP with certificates of analysis.