Registration Dossier
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EC number: 233-662-6 | CAS number: 10294-54-9
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
A toxicity study to aquatic algae and cyanobacteria with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate. Under the conditions of this acute algal growth inhibition test on Pseudokirchneriella subcapitata the observed endpoints for the effect of cesium hydroxide monohydrate based on the growth rate were the following: 72h EC50 value: 133.99 mg test item/L; 72h NOEC value: 12.5 mg test item/L and 72h LOEC value: 25 mg test item/L.
Based on these data the 72h-EC50 calculated for cesium was 106.1 mg/L., the 72h-LOEC was 19.8 mg/L and the 72h NOEC was 9.9 mg/L and for cesium sulphate the calculated 72h-EC50 value was 144.4, the 72h-LOEC was 26.9 mg/L and the 72h NOEC was 13.5 mg/L. All reported biological results are related to the nominal concentrations.
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 144.4 mg/L
- EC10 or NOEC for freshwater algae:
- 13.5 mg/L
Additional information
A toxicity study to aquatic algae and cyanobacteria with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate.
An Acute Growth Inhibition Test of cesium hydroxide monohydrate on Algae (Pseudokirchneriella subcapitata) over an exposure period of 72 hours in a static system was assessed according to OECD Guideline 201 and EU method C.3. Five different concentrations arranged in a geometric series and an untreated control group were tested in the main study. The highest concentration was 100 mg/L. The following concentrations were used in the main study: 6.25; 12.5; 25, 50 and 100 mg/L. The shape of the algal cells growing was obviously not affected. Under the conditions of this acute algal growth inhibition test on Pseudokirchneriella subcapitata the observed endpoints for the effect of cesium hydroxide monohydrate based on the growth rate were the followings: 72h EC50 value: 133.99 mg test item/L; 72h NOEC value: 12.5 mg test item/L and 72h LOEC value: 25 mg test item/L.
Based on these data the 72h-EC50 calculated for cesium was 106.1 mg/L., the 72h-LOEC was 19.8 mg/L and the 72h NOEC was 9.9 mg/L and for cesium sulphate the calculated 72h-EC50 value was 144.4 mg/L, the 72h-LOEC was 26.9 mg/L and the 72h NOEC was 13.5 mg/L.Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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