Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Typically the purity of disodium dihydrogenpyrophosphate is > 90% (dry weight, after excluding water). All impurities present at >1% are other inorganic phosphates or other related inorganic substances, similar to the registered substance, and which do not significantly affect its toxicological and ecotoxicological properties. There are no hazardous impurities present within the substance at levels >0.1%.

 

Disodium dihydrogenpyrophosphate has a melting point of >450°C and is considered to be very soluble (170 g/l of solution at 20.0 ± 0.5°C). The pH of this solution, observed in the water solubility study, was pH 3.8-3.9. The water solubility study conducted on disodium dihydrogenpyrophosphate made the following observations:

The effect of temperature over the range 10 to 30°C has been considered not to have had a significant influence on the solubility of the test material (range 169 to 173 g/l). 

The solubility of the test material over the environmentally relevant pH range of 4 to 9 gave solubility results and final solution pH’s similar to those obtained using unbuffered water (range 172 to 175 g/l). Thus, it can be anticipated that the water solubility of the test material over the pH range 4 to 9 would be constant, essentially due to the low buffering activities seen in the environment.

 

Disodium dihydrogenpyrophosphate is not considered to possess any of the following hazardous physico-chemical properties: autoflammability and/or self-ignition, flammability, explosiveness and oxidising properties.