Diphosphoric acid
Description
Diphosphoric acid (CAS 2466-09-3), also known as pyrophosphoric acid, is an inorganic condensed phosphoric acid used across food processing, pharmaceutical manufacturing, and water treatment.
It functions as a pH buffer, chelating agent, and stabilizer, controlling mineral interactions and acid balance in complex formulations. In food processing, it regulates acidity and sequesters metal ions.
These ions would otherwise accelerate oxidative spoilage in packaged and processed products. Pharmaceutical manufacturers use it as a buffering agent in liquid formulations where precise pH control is critical.
This stability is essential for active ingredients. In water treatment, it chelates calcium and magnesium ions to prevent scale formation in industrial cooling and distribution systems.
It also acts as a sequestrant in emulsified and dairy-based products, preventing discoloration and texture degradation caused by trace metal contamination during the manufacturing process.
Diphosphoric acid is supplied as a liquid solution, with concentration and purity varying by application. Food-grade and technical-grade specifications are the most commonly available formats.
Pharmaceutical-grade material is supplied to USP or Ph. Eur. standards where required. Buyers should confirm grade, concentration, and packaging format with their chemical suppliers.
Specifications can differ significantly between industrial and regulated end-use markets. Proper documentation ensures compliance with safety and quality requirements for specific industrial applications.
Physical Properties
| Melting Point | 61 °C |
| Density | approximate 1.9g/ml (25℃) |
| Appearance | White to very pale yellow glassy solid |
| Color | white crystals, crystalline |
| Form | white crystals |
| Water Solubility | 709g/100mL H2O (23°C); soluble alcohol, ether [MER06] |
| pH | pKa1= 0.86, pKa2 = 1.76, pKa3 = 5.88, pKa4 = 8.14(25℃) |
Safety & Handling (Learn More)
Trade & Regulatory
| HS Code | 28092000 |
| UN Number | 3260 |
| ADR Class | 8 |
| Packing Group | II |
| WGK (Germany) | 3 |
Documentation
Other Names
Pyrophosphoric Acid ( Acide Diphosphorique)|phosphono dihydrogen phosphate|Pyrophosphoric acid
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