Rubidium nitrate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 December 2016 to 03 January 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

OECD Guidelines for Testing of Chemicals (April 2004) No 202 "Daphnia sp., Acute Immobilisation Test"

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification:
Rubidium nitrate
Physical state/Appearance:
White powder
Batch:
215091B002
Purity:
≥80% - ≤100%
Expiry Date:
01 September 2017
Storage Conditions:
Room temperature, over silica gel, in the dark
Intended use/Application:
Raw material for chemical industry. Catalyst

Analytical monitoring:

yes

Details on sampling:

Analysis of the test preparations at 0 and 48 hours (see Annex 5 of stuy report) showed measured test concentrations to be near nominal concentrations and so the results are based on nominal test concentrations.

Vehicle:

yes

Details on test solutions:

Based on the results of the range-finding test the following test concentrations were assigned to the definitive test: 10, 18, 32, 56 and 100 mg/L.
A nominal amount of test item (200 mg) was dissolved in test water and the volume adjusted to 2 liters to give the 100 mg/L test concentration from which a series of dilutions was made to give further test concentrations of 10, 18, 32 and 56 mg/L.
Each prepared concentration was inverted several times to ensure adequate mixing and homogeneity.
The concentration and stability of the test item in the test preparations were verified by chemical analysis at 0 and 48 hours

Test organisms (species):

Daphnia magna

Details on test organisms:

The test was carried out using 1st instar Daphnia magna derived from in-house laboratory cultures.
Adult daphnia were maintained in 150 mL glass beakers containing Elendt M7 medium (see Annex 2) in a temperature controlled room maintaining the water temperature at 18 to 22 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.
A positive control (Envigo Study Number MS29MC) used potassium dichromate as the reference item. Details of the positive control are given in Annex 3. The positive control was conducted between 29 February 2016 and 02 March 2016.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Hardness:

The reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3.

Test temperature:

21 deg C

pH:

7.8 to 7.9

Dissolved oxygen:

8.5 to 9.0 mg O2/L

Details on test conditions:

As in the range-finding test 150 mL glass beakers containing approximately 100 mL of test preparation were used. At the start of the test 5 daphnids were placed in each test and control vessel at random, in the test preparations. Four replicate test and control vessels were prepared. The test vessels were then covered to reduce evaporation and maintained in a temperature controlled room maintaining the water temperature at 18 to 22 °C with a maximum deviation of ±1 °C with a photoperiod of 16 hours light (between 200 and 1200 Lux) and 8 hours darkness with 20 minute dawn and dusk transition periods. The daphnids were not individually identified, received no food during exposure and the test vessels were not aerated.
The control group was maintained under identical conditions but not exposed to the test item.
The test preparations were not renewed during the exposure period.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 67 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

ca. 56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Analysis of the test preparations at 0 and 48-Hours showed measured test concentrations to be near nominal concentrations and so the results are based on nominal test concentrations.
Exposure of Daphnia magna to the test item gave the following results as tabulated above.

Validity criteria fulfilled:

yes

Conclusions:

The No Observed Effect Concentrations after 24 and 48 hours exposure were 100 and 32 mg/L respectively. The Lowest Observed Effect Concentrations after 24 and 48 hours exposure were greater than 100 and 56 mg/L respectively.

Executive summary:

A study was performed to assess the acute toxicity of the test substance to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test substance at nominal concentrations of 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 21 °C under static test conditions. The number of immobilized daphnia were recorded after 24 and 48 hours. Analysis of the test preparations at 0 and 48-Hours showed measured test concentrations to be near nominal concentrations and so the results are based on nominal test concentrations. The No Observed Effect Concentrations after 24 and 48 hours exposure were 100 and 32 mg/L respectively. The Lowest Observed Effect Concentrations after 24 and 48 hours exposure were greater than 100 and 56 mg/L respectively.

Description of key information

A study was performed to assess the acute toxicity of the test substance to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test substance at nominal concentrations of 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 21 °C under static test conditions. The number of immobilized daphnia were recorded after 24 and 48 hours. Analysis of the test preparations at 0 and 48-Hours showed measured test concentrations to be near nominal concentrations and so the results are based on nominal test concentrations. The No Observed Effect Concentrations after 24 and 48 hours exposure were 100 and 32 mg/L respectively. The Lowest Observed Effect Concentrations after 24 and 48 hours exposure were greater than 100 and 56 mg/L respectively.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

67 mg/L