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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Water solubility

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Administrative data

Link to relevant study record(s)

Description of key information

Values from two studies are available:
- 909 g/L at 30°C (5.8<pH<5.9) (EU method A6) (Reuse, 2009)
- 744 g/L at 20°C (flask method) (Besse, 1998)

Key value for chemical safety assessment

Water solubility:
909 g/L
at the temperature of:
30 °C

Additional information

The experimental study of Reuse (2009) was chosen as the key study out of the two studies available as it is reliable without restrictions (Klimisch 2: guideline study with acceptable restrictions; no precision on the type of method applied). This study was performed according to method A6 requirements from regulation (CE) n°440/2008 and OECD guideline 105 under ISO 17025. In these test conditions, sodium hypophosphite is very soluble, 909 g/L at 30°C (5.8<pH<5.9) and it is not expected that the water solubility is different at ambient temperature.


The study of Besse (1998) was not a guideline study and solubility was assessed using the flask method. In the test conditions, sodium hypophosphite was very soluble at 20°C (i.e. 744 g/L). These results are considered as not assignable as documentation is insufficient for assessment.