Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Silicate(2-), hexafluoro-, disodium, reaction products with lithium magnesium sodium silicate disperses in water to form a colloidal suspension rather than a solution. The colloidal suspension is slightly cloudy giving the appearance of a solution. This substance is insoluble in water, as demonstrated by dialysis at its natural pH in water of 8.4 and a temperature of 26 deg C

Key value for chemical safety assessment

Additional information

This substance is an inorganic layered silicate structure with a unit cell of the following composition


The material is non-biodegradable, retaining its clay structure in the environment. At normal water course pH’s this material is stable and insoluble. It does not dissolve in water but disperses to form a clear sol so the usual methods to determine water solubility do not work because it appears by observation that total dissolution has taken place whereas in reality the structure has remained unchanged but simply dispersed to be invisible to the naked eye. To demonstrate whether any solubility to the component ions takes place, adialysis method was devised to determine solubilised ions present. Based on the structure above, lithium, sodium and magnesium were determined to be key identifiers of whether the structure under defined conditions dissociates in water. The natural pH of this substance in water at a concentration of 2% by weight is 8.4. At that pH, no free lithium or magnesium ions are found in solution and only low level concentration of sodium ions which are present from dissociation of free sodium sulphate left over from the manufacturing process as a low level impurity. Some free fluoride can also be measured as being available when the material is dialysed under these conditions. The level of fluoride may be consistent with ionic impurities and does not suggest that the actual clay structure is exhibiting a solubility.