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Ecotoxicological information

Endpoint summary

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Additional information

Short-term toxicity study to fish:

A short-term toxicity study to fish with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate.

Under the conditions of this acute fish toxicity study the observed endpoints for the effect of cesium hydroxide monohydrate were the followings: 96h NOEC value: ≥ 100 mg test item/L; 96h LOEC value: > 100 mg test item/L and 96h LC50 value: > 100 mg test item/L. Based on these data the calculated values of 96h-LC50, 96h-LOEC and 96h-NOEC for cesium are greater than 79.2 mg/L and for cesium sulphate are greater than 107.8 mg/L.

Long-term toxicity study to fish:

A long-term toxicity study to fish with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate. Under the conditions of this early life stage toxicity study, the test item had no significant lethal or sub-lethal effects on early life stages of Zebrafish (Danio rerio).

The calculated endpoints (35 days LOEC and NOEC) were the following in this test:

The 35 d LOEC         > 43.0 mg test item/L

The 35 d NOEC = 43.0 mg test item/L

Based on these data, the calculated NOEC for cesium was 34.0 mg/L and the LOEC was greater than 34.0 mg/L and for cesium sulphate the calculated NOEC was 46.3 mg/L and the LOEC was greater than 46.3 mg/L.

Short-term toxicity study to aqueous invertebrates:

In this 48-hour acute toxicity test with Daphnia magna with cesium sulphate the 48 h EC50 value was determined as 91.2 mg/L, and the 48 h NOEC was determined to be 76.9 mg/L. The results are based on the nominal test item concentrations.

Long-term toxicity study to aqueous invertebrates:

A long-term toxicity study to aquatic invertebrates with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate. Under the conditions of this chronic daphnia toxicity study the observed endpoints related to reproduction for the effect of cesium hydroxide monohydrate were the following: 21d NOEC: 15.8 mg/L; 21d LOEC: 30.0 mg/L; 21d EC50: > 15.8 mg/L. All reported biological results are related to the nominal concentration.

Based on these data, the calculated 21d-NOEC for cesium was 12.5 mg/L, the 21d-EC50 > 12.5 mg/L and the LOEC > 23.7 mg/L and for cesium sulphate the calculated 21d-NOEC was 17.0 mg/L, the 21d-EC50>17.0 mg/L and the LOEC = 32.3 mg/L.

Toxicity to aquatic algae:

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.

Toxicity to microorganisms:

A toxicity study to microorganisms with cesium sulphate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate. Under the conditions of the performed Activated Sludge Respiration Inhibition Test, the EC10 and EC50 values of cesium hydroxide monohydrate were determined as higher than 1000 mg/L. Based on the statistical evaluation in this test the NOEC was 1000 mg/L for cesium hydroxide monohydrate.

Based on these data, the calculated EC10 and EC50 values of cesium were greater than 792 mg/L and the NOEC was 792 mg/L and for cesium sulphate the calculated values were as follows: EC10 and EC 50 >1077.6 mg/L and NOEC 1077.6 mg/L.

Please refer to IUCLID section 13 for read-across justification.