Aluminate(1-), tetrafluoro-, cesium (1:1), (T-4)-

Short-term toxicity to fish

Description of key information

The 96-h LC50 value for cesium tetrafluoroaluminate in Gobiocypris rarus was >120 mg/L based on nominal concentrations. The 96-h LC50 of cesium fluoro aluminate complex in Cyprinus carpi was >100 mg/L corresponding with an average exposure concentration of 40.1 mg/L. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

40.1 mg/L

Additional information

Two reliable acute toxicity data points (Klimisch 1, GLP) for fish species have been identified. One study was conducted with cesium tetrafluoroaluminate and the other study was conducted with the structural analogue cesium fluoro aluminate complex (for details see Reporting Format as attached to the respective IUCLID entry and CSR Appendix B.2).

A GLP-compliant OECD 203 guideline study with Gobiocypris rarus was conducted as part of a new chemical substance notification in China. The study was conducted as semi-static limit test at a nominal concentration of 120 mg/L. The treatment group and the control group had one replicate, each containing 10 fish and the test duration was 96h. No mortality occurred in the control during the test and the dissolved oxygen concentration was greater than 60% of the air saturation value throughout the test. Hence, the test was considered to be valid. During the test, the measured concentration of aluminum (Al) analysed by ICP-MS, varied greater than 20% during the test. Since the test substance consists of a variety of elements (Cs, Al and F), the measured concentrations of the test substance were not actually calculated by the measured concentrations of Aluminium analyzed by ICP-MS. In order to reflect the toxicity of the test substance, the results were expressed as the nominal concentrations. The 96h LC50 value (based on the nominal concentrations) for cesium tetrafluoroaluminate was >120 mg/L.

One GLP-compliant OECD 203 guideline study with Cyprinus carpi is available for the structural analogue cesium fluoro aluminate complex (Notox B.V. 1999). The test was conducted as a limit test in which 7 fish were exposed for 96 hours under static conditions to a nominal concentration of 100 mg/L. The test concentration was analytically verified. Analysis of the samples showed that the actual concentration of Aluminium in the water phase had decreased by more than 20% after 96 hours. This decrease corresponded with the observation of precipitation during the exposure period probably due to the formation of low soluble salts of aluminium with anions present in the test medium. The time weighed average concentration of cesium fluoro aluminate complex was calculated as 40.1 mg/L. No mortality was observed in the control group. No mortality nor effects on behavior an general appearance occurred during the 96 -hour test period at a nominal concentration of 100 mg/L. Hence, the 96h-LC50 for carp exposed to cesium fluoro aluminate complex was >100 mg/L corresponding with an average exposure concentration of 40.1 mg/L.

The lowest observed value, 96-h LC50 of 40.1 mg/l will be used in the assessment.