Pyrophosphoric acid
CAS 2466-09-3
EC 219-574-0
Formula H4O7P2
MW 177.98 g/mol
Inorganic Acids Water TreatmentPharmaceuticals & HealthcareFood & Nutrition Chelation & SequestrationpH Regulation & BufferingAntioxidant & Stabilizer
Description
Pyrophosphoric acid (CAS 2466-09-3), also known as diphosphoric acid or Diphosphorsäure, is an inorganic acid formed by the condensation of two phosphoric acid molecules. It carries no assigned E-code and is commercially available under both its common and systematic trade designations. Its molecular formula is H4O7P2.
In water treatment, pyrophosphoric acid functions as a sequestrant by binding divalent metal ions such as calcium and magnesium, preventing scale formation in process equipment. In pharmaceutical and food-grade applications, it serves as a pH buffer and stabilizer, where its pyrophosphate anions coordinate with metal catalysts that would otherwise accelerate oxidative degradation.
Pyrophosphoric acid is sourced in technical and food-grade specifications, with food-contact grades subject to FCC compliance requirements. It falls under REACH registration obligations within the EU (EC 219-574-0) and is classified under HS code 28092000. Packaging formats typically reflect industrial supply volumes and are confirmed at the point of inquiry.
In water treatment, pyrophosphoric acid functions as a sequestrant by binding divalent metal ions such as calcium and magnesium, preventing scale formation in process equipment. In pharmaceutical and food-grade applications, it serves as a pH buffer and stabilizer, where its pyrophosphate anions coordinate with metal catalysts that would otherwise accelerate oxidative degradation.
Pyrophosphoric acid is sourced in technical and food-grade specifications, with food-contact grades subject to FCC compliance requirements. It falls under REACH registration obligations within the EU (EC 219-574-0) and is classified under HS code 28092000. Packaging formats typically reflect industrial supply volumes and are confirmed at the point of inquiry.
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)
Danger GHS05 GHS07
H
H302H314H318H332
P
P260P261P264P270P271P280P316P317P321P330P363P405P501P264+P265P301+P317P304+P340P301+P330+P331P302+P361+P354P305+P354+P338
Trade & Regulatory
| HS Code | 28092000 |
| UN Number | 3260 |
| ADR Class | 8 |
| Packing Group | II |
| WGK (Germany) | 3 |
Other Names
phosphono dihydrogen phosphatePyrophosphateDiphosphorsäureDiphosphoric acidDiphosphoric(V) acid
Related Products
Raw Materials
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