Cesium acetate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

2011-05-31 to 2011-08-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, OECD study

Justification for type of information:

In water, cesium acetate will dissociate into cesium and acetate ions. Therefore, aquatic animals living in the column water will never be in direct contact with cesium acetate as such. For short-term toxicity to aquatic invertebrates, no study is currently availbale for cesium acetate. Howevr, due to the dissociation in water, toxicity to invertebrate can be extrapolated from studies made from available cesium salts and acetate.
In this dossier, the toxicity provokes by the cesium ion has been provide with cesium hydroxide and cesium nitrate. In addition, toxicity to acetate has also been provided.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

,updated 13th April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

, dated May 30, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling preparation:
For the analysis of the test item concentration, samples from the test media of the test concentration and the control were taken at the start and at the end of the experiment. Representative samples in duplicate series were taken. One series were sent for analysis, and were analyzed immediately after sampling. The analysis was performed depending on the results of the analytical method validation.

- Storage of the Samples: The second series of samples were stored in a refrigerator immediately after sampling, and were kept stored until delivery of the final report to enable additional analyses on request of the sponsor. After delivery of the final report, all samples will be discarded.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Formulation: At the preparation of the test item stock solution 50 mg test item was weighted and emulsified in 500 mL ISO Medium and further diluted.

Untreated Control: ISO Medium with daphnids (without test item) was examined in parallel in the experiment.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age: Less than 24 hours old
- Sex: female
- Feeding, Aeration: None
- Acclimatization: The Daphnia mothers selected ca. one months prior to the start of the test were maintained in ISO medium under test conditions (temperature, light conditions, quality and content of reconstituted water, pH and total hardness).
The test animals were fed daily with a few mL of centrifuged algae (Pseudokirchneriella subcapitata) suspension.
To avoid the necessity of longer adaptation prior to the test, the water used in the test is similar (or the same) to the culture conditions (water temperature, background colour, light intensities).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

226.1 mg/L

Test temperature:

20.2 – 20.9 °C in the climate chamber
20.5 – 20.9 oC in the test vessels

pH:

pH 8.23 to 8.39 at the start of the test
pH 8.34 to 8.47 at the end of the test

Dissolved oxygen:

8.52 to 8.62 mg/L at test start of the test
8.20 to 8.31 mg/L at test end of the test

Nominal and measured concentrations:

Nominal 6.25; 12.5; 25, 50 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers of 50 mL volume with ~40 mL test medium
- No. of organisms per vessel: There were 20 animals at each group (concentration and untreated control) divided into 4 parallel. 5 animals were investigated/parallel.


OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED:
NOEC (48 h):No Observed Effect Concentration: highest test concentration at which no significant effect is determined after 48 hours test duration
EC 50: the calculated concentration of the test item which results in a 50 % immobilisation rate
EC 0: highest test concentration without a significant number of immobilised test animals
EC 100: the lowest test concentration at which all test animals are immobile


TEST CONCENTRATIONS
- Range finding study: Two non-GLP preliminary range-finding tests were performed. In the first range-finding test the examined nominal concentrations were: 0.1, 1, 5, 10, 50 and 100 mg test item/L. In the second range-finding test the same concentration range was investigated.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

94.44 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

CsOH monohydrate

Basis for effect:

mobility

Remarks on result:

other: 95%CL:63.5 - 216.05 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

CsOH monohydrate

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

CsOH monohydrate

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

CsOH monohydrate

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

84.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for CsOH anhydrous

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

22.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for CsOH anhydrous

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

22.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for CsOH anhydrous

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

44.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for CsOH anhydrous

Basis for effect:

mobility

Results with reference substance (positive control):

24-hour EC50 of Potassium dichromate: 1.84 mg/L (95 % confidence limits: 1.44 – 2.43 mg/L).
24-h NOEC: 0.50 mg/L.
This 24-hour EC50 value is in accordance with the accepted 0.6 – 2.1 mg/L range for Daphnia magna.

The analytically determined mean test item concentrations in the analysed test media varied in the range from 101 % to 113 % of the nominal value at the start of the study and from 96 % to 111 % at the end of the study (see the attached analytical report). The measured concentrations remained within the range of ± 20% of nominal during the study, therefore, all reported biological results are related to the nominal concentrations applied in the test.

Validity criteria fulfilled:

yes

Conclusions:

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 hydroxide anhydrous was 84.3 mg/L, the 48h-LOEC was greater than 44.6 mg/L and the 48h-NOEC was 22.3 mg/L.
As this study is used as read-across for extrapolating the toxicity value for cesium acetate, the values once converted are the following: 48h-EC50 for cesium acetate was 108.2 mg/L, the 48h-LOEC was greater than 57.11 mg/L and the 48h-NOEC was 28.55 mg/L.

Executive summary:

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 hydroxide anhydrous was 84.3 mg/L, the 48h-LOEC was greater than 44.6 mg/L and the 48h-NOEC was 22.3 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

2011-12-02 to 2012-02-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to guideline.

Justification for type of information:

In water, cesium acetate will dissociate into cesium and acetate ions. Therefore, aquatic animals living in the column water will never be in direct contact with cesium acetate as such. For short-term toxicity to aquatic invertebrates, no study is currently availbale for cesium acetate. Howevr, due to the dissociation in water, toxicity to invertebrate can be extrapolated from studies made from available cesium salts and acetate.
In this dossier, the toxicity provokes by the cesium ion has been provide with cesium hydroxide and cesium nitrate. In addition, toxicity to acetate has also been provided.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

,updated 13th April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

, dated May 30, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling preparation:
For determination of the test item concentration, samples were taken from the testing concentrations and the control at the start and at the end of the experiment.

- Storage of the Samples: Samples were taken in duplicate series. One series was stored frozen in the testing laboratory, one series was analysed immediately after sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Formulation: The test solutions used in the test were prepared by mechanical dispersion without using of any solubilising agent. The test solutions were freshly prepared at the beginning of the experiment, in the testing laboratory.

Untreated Control: The dilution water (ISO-medium) was used without addition of the test item.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Age: Less than 24 hours old
- Sex: female
- Feeding, Aeration: None
- Acclimatization: Test animals were bred under similar conditions as that used during the exposure period, therefore additional acclimatisation before the test was not necessary.
- Breeding conditions: Daphnia were bred in the Laboratory of TOXI-COOP ZRT. under similar temperature and light conditions as in the test, and in reconstituted water of a similar quality regarding to pH, components of the main ions and total hardness as the test water used in the test. The test animals were fed with centrifuged green alga suspension.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

249 mg/L (as CaCO3).

Test temperature:

The test temperature was in the range of 19.5 – 20.5 °C measured in the test vessels during the test. The additionally measured ambient temperature within the climate chamber was between 20.0 – 21.1 °C.

pH:

pH 7.97 to 8.09

Dissolved oxygen:

8.25 to 8.58 mg/L

Nominal and measured concentrations:

Nominal 35.0; 45.5; 59.2; 76.9 and 100.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers of approximately 40 mL test medium
- No. of organisms per vessel: Twenty animals at each group, divided into 4 replicates.


OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 16 hours light (artificial illumination) and 8 hours darkness

EFFECT PARAMETERS MEASURED:
EC 50: concentration estimated to immobilise 50 per cent of the daphnids within a stated exposure period
EC100: the lowest test concentration at which all test animals are immobile.
NOEC (48 h, No Observed Effect Concentration) the highest test concentration at which no significant immobilisation or abnormal behaviour is observed relative to the control.
LOEC: (Lowest Observed Effect Concentration) the lowest test concentration at which a significant immobilisation or abnormal behaviour is observed relative to the control.

TEST CONCENTRATIONS
- Range finding study: Two non-GLP preliminary range-finding tests were performed. In the first range finding test, five widely spaced concentrations (0.01-100 mg/L) with a separation factor of 10 was used. The results of this pre-test were completed in a second range finding test using one additional concentration of 50 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

98.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95%CL:91.5 - 111.6 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

76.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

77.87 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for cesium

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

60.86 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for cesium

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

79.14 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for cesium

Basis for effect:

mobility

Results with reference substance (positive control):

The 24-hour EC50 of Potassium dichromate: 2.05 mg/L, (95 % confidence limits: 1.76 – 2.43 mg/L).

Five different concentrations arranged in a geometric series and an untreated control group was tested in the experiment. The nominal test item concentrations were 35.0; 45.5; 59.2; 76.9 and 100.0 mg/L. The measured concentrations of cesium nitrate varied between 95 and 105 % of the nominal concentration during the experiment.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this acute daphnia toxicity study (OECD 202) the observed endpoints for the effect of cesium nitrate were the following: 48h NOEC value: 76.9 mg test item/L; 48h LOEC value: 100 mg test item/L and 48h EC50 value: 98.4 mg test item/L. All reported biological results are related to the nominal concentrations.
Based on these data the calculated NOEC for cesium was 60.86 mg/L, the EC50=77.87 mg/L and the LOEC=79.14 mg/L. Expressed in terms of cesium acetate, the values are: NOEC: 87.90 mg/L, the EC50=112.46 mg/L and the LOEC=114.30 mg/L.

Executive summary:

Acute toxicity 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 nitrate arranged in a geometric series and an untreated control group was tested in the main experiment. The nominal concentrations were: 35.0; 45.5; 59.2; 76.9 and 100.0 mg/L. The 48 h EC50 value was determined to be 98.4 mg/L, and the 48 h NOEC was determined to be 76.9 mg/L.

Based on these data the calculated NOEC for cesium was 60.86 mg/L, the EC50=77.87 mg/L and the LOEC=79.14 mg/L.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

supporting study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: published data used in OECD SIDS program

Justification for type of information:

In water, cesium acetate will dissociate into cesium and acetate ions. Therefore, aquatic animals living in the column water will never be in direct contact with cesium acetate as such. For short-term toxicity to aquatic invertebrates, no study is currently availbale for cesium acetate. Howevr, due to the dissociation in water, toxicity to invertebrate can be extrapolated from studies made from available cesium salts and acetate.
In this dossier, the toxicity provokes by the cesium ion has been provide with cesium hydroxide and cesium nitrate. In addition, toxicity to acetate has also been provided.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus IRCHA

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

55 mg/L

Conc. based on:

test mat.

Remarks on result:

other: values reported here are without neutralization

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

47 mg/L

Conc. based on:

test mat.

Remarks on result:

other: values reported here are without neutralization

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

68 mg/L

Conc. based on:

test mat.

Remarks on result:

other: values reported here are without neutralization

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

1 370 mg/L

Conc. based on:

test mat.

Remarks on result:

other: Value reported after neutralization

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3 200 mg/L

Conc. based on:

test mat.

Remarks on result:

other: Value reported after neutralization

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

5 900 mg/L

Conc. based on:

test mat.

Remarks on result:

other: Value reported after neutralization

Validity criteria fulfilled:

not specified

Conclusions:

Short-term toxicity on Daphnia magna with Acetanhydrid (acetic anhydride) provided the following results:
- 24 hr. LC50 = 55 mg/l (95% confidence interval 53-58 mg/l)
- 24 hr. LC0 = 47 mg/l
- 24 hr. LC100 = 68 mg/l
BUT once we neutralise the acid - the values become:
- 24 hr. EC0 = 1370 mg/l (95% confidence interval 53-58 mg/l)
- 24 hr. EC50 = 3200 mg/l
- 24 hr. EC100 = 5900 mg/l

In conclusion, we can easily extrapolate that acetate is not an adverse ion for daphnia.

These results have been publised by Bringmann, G., and R. Kuhn (1982) and used by the OECD SIDS program 1997.

Description of key information

No short-term toxicity to aquatic invertebrates is currently existing for cesium acetate. However, to fulfil the requirement, read-across strategy with cesium salts have been used to assess the toxicity of cesium acetate (cesium ion) and supporting studies with acetic anhydride to provide data induced by acetate (acetic anhydride is rapidly hydrolyzed (half-life 4.4 min.) to acetic acid which then, ends into acetate and H+).

* CsOH.H2O

Under the conditions of this acute daphnia toxicity study (OECD guideline N°202), 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 hydroxide anhydrous was 84.3 mg/L, the 48h-LOEC was greater than 44.6 mg/L and the 48h-NOEC was 22.3 mg/L.

Finally, by extrapolated the above values into cesium acetate, the values are the following: 48h-EC50 for cesium acetate was 108.2 mg/L, the 48h-LOEC was greater than 57.11 mg/L and the 48h-NOEC was 28.55 mg/L.

*CsNO3

Under the conditions of this acute daphnia toxicity study (OECD 202) the observed endpoints for the effect of cesium nitrate were the following: 48h NOEC value: 76.9 mg test item/L; 48h LOEC value: 100 mg test item/L and 48h EC50 value: 98.4 mg test item/L. All reported biological results are related to the nominal concentrations.

Based on these data the calculated NOEC for cesium was 60.86 mg/L, the EC50=77.87 mg/L and the LOEC=79.14 mg/L. Expressed in terms of cesium acetate, the values are: NOEC: 87.90 mg/L, the EC50=112.46 mg/L and the LOEC=114.30 mg/L.

* Acetic anhydride

Short-term toxicity on Daphnia magna with Acetanhydrid (acetic anhydride) provided the following results:

- 24 hr. LC50 = 55 mg/l (95% confidence interval 53-58 mg/l)

- 24 hr. LC0 = 47 mg/l

- 24 hr. LC100 = 68 mg/l

BUT once we neutralise the acid - the values become:

- 24 hr. EC0 = 1370 mg/l (95% confidence interval 53-58 mg/l)

- 24 hr. EC50 = 3200 mg/l

- 24 hr. EC100 = 5900 mg/l

 In conclusion, we can easily extrapolate that acetate is not an adverse ion for daphnia.

These results on acetic anhydride have been publised by Bringmann, G., and R. Kuhn (1982) and used by the OECD SIDS program 1997.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

84.3 mg/L