Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

READ-ACROSS JUSTIFICATION

When environmental data required by REACH regulation are missing for Lithium cryolite, a read-across approach with Sodium cryolite (CAS RN: 13775-53-6) is performed. This approach is justified by the information below:

1) Structural similarity

Both substances are cryolite salts and therefore have similar chemical structure. The only difference between the two substances is the cation which is Lithium for Lithium cryolite and Sodium for Sodium cryolite.

2) Similar bioavailability

Both substances are a crystalline inorganic solid soluble in water (water solubility at 20°C of 0.602 g/L for Sodium cryolite and 1.1 g/L for Lithium cryolite). They are expected to have a low volatility.

In the aquatic environment, both substances dissociate into hexafluoroaluminate anion (AlF6(3 -)) and the Li+ or Na+ cations. Therefore, the bioavailability of the cryolite moiety should be the same for both substances. Additionally, the degradability of both substances is not applicable because they are inorganic.

Based on the above information, both substances should show similar bioavailability to organisms in the environment, and similar fate and behaviour in and between the environmental compartments.

 

To conclude, based on the similar chemical structure and bioavailability, the degradation information obtained on Sodium cryolite can be used to assess the environmental profile of Lithium cryolite. Data on Sodium cryolite are reported in the REACH registration dossier submitted by the same registrant as the present dossier. In order to avoid repeating all data and information on Sodium cryolite, which can make the read-across approach difficult to understand, only key studies obtained on Sodium cryolite are reported in the read-across approach in the present dossier for Lithium cryolite.

The data available on Lithium (CAS RN: 7439 -93 -2) are also used in order to be able to conclude on the entire substance.