Caesium carbonate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

HYPOTHESIS FOR THE ANALOGUE APPROACH
Cesium carbonate completely dissociates in water forming cesium cation and the corresponding carbonate anion. Thus, cesium salts with different anion moieties were found to be suitable candidates for read-across. (Eco)toxicological properties were extrapolated to different endpoints by using the lowest effect concentration.
For further information, please refer to the read-across justification in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for Cs

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for Cs

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

24 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for Cs2CO3

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

92 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for Cs2CO3

Basis for effect:

mobility

Description of key information

A short-term toxicity study to aquatic invertebrates with cesium carbonate is not available. Consequently, read-across was applied using data from cesium hydroxide monohydrate. Under the conditions of this acute daphnia toxicity study the observed endpoints for the effect of cesium hydroxide monohydrate were the following: 48h NOEC value: 25 mg test item/L; 48h LOEC value: > 50 mg test item/L and 48h EC50 value: 94.44 mg test item/L. All reported biological results are related to the nominal concentrations.  Based on these data, the calculated 48h-EC50 for cesium carbonate was 91.6 mg/L, the 48h-LOEC was greater than 48.5 mg/L and the 48h-NOEC was 24.3 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

92 mg/L

Additional information

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

An acute toxicity test on Daphnia magna over an exposure period of 48 hours in a static system was assessed according to OECD Guideline 202 and EU method C.2. Five different concentrations of cesium hydroxide monohydrate arranged in a geometric series and an untreated control group was tested in the main experiment. The concentrations were in nominal: 6.25; 12.5; 25, 50 and 100 mg/L. The highest concentration tested without toxic effects after the exposure period of 48 hours, the 48h-NOEC and the 48h-EC0 of cesium hydroxid monohydrat to Daphnia magna was determined to be 25 mg/L. 5 % mortality was observed at the concentrations of 6.25 and 12.5 mg/L and in the control group, however this mortality was within the assay acceptance range; therefore the observed mortality was not evaluated as an effect. Immobilisation observed at 100 mg/L test item concentration was significantly different from the control (Dunnett’s Test). The 48h-LOEC was greater than 50 mg/L, while the 48h-EC50 was calculated to be 94.44 mg/L. All reported biological results are related to the nominal concentrations.

Based on these data, the calculated 48h-EC50 for cesium carbonate was 92 mg/L, the 48h-LOEC was greater than 48.5 mg/L and the 48h-NOEC was 24 mg/L.