Tetraammonium decachloro-μ-oxodiruthenate(4-)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples taken from control media and each test concentration
- Sampling method: Samples were taken at test start and in fresh solutions at renewal at 48-hours, and in aged test solutions after 48 hours and at test end
- Sample storage conditions before analysis: Samples were acidified for stabilisation by addition of 2.5 mL of conc. nitric acid

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST MEDIUM
- Method: The quantity of test item required to obtain the desired concentrations was applied as an aqueous stock solution. The stock solution (containing 200 mg tetraammonium decachloro-mu-oxodiruthenate/L) was prepared in dilution water and stirred for approximately 2.5 hours. The individual test solutions were prepared by dilution of the respective stock solution with dilution water and sampled thereafter for chemical analysis. The test solutions were freshly prepared before test start and renewal after 48-hours.
- Controls: Untreated dilution water

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Danio rerio (Teleostei, Cyprinidae)
- Source: Test facility bred (West Aquarium GmbH, 37431 Bad Lauterberg, Germany)
- Length at study initiation: 2.0 ± 1 cm
- Holding water: Purified drinking water
- Holding conditions: Fish were fed ad libitum throughout the holding period with live brine shrimp (Artemia salina) nauplii, and ground flake food TetraMin® (Tetra Werke, Melle, Germany) once daily.
- Health: Only fish without diseases and abnormalities were used in the study (mortality < 5%).
- Feeding during test: None from 24 hours before test start

ACCLIMATION
- Period: Test fish were acclimatised for at least 12 days.
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: Fed ad libitum, type not specified
- Feeding frequency: ad libitum
- Health during acclimation (any mortality observed): Less than 5% during the last week before the study

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

The total hardness of dilution water was 1.1 mmol/L

Test temperature:

The temperature was in the range of 22.9°C and 23.0°C.

pH:

The pH in the test vessels was between 7.38 and 8.66.

Dissolved oxygen:

The oxygen saturation in all test vessels was vetween 91% and 103%.

Nominal and measured concentrations:

The test concentrations applied were based on the results of a non GLP range finding test with nominal concentrations of 0.05, 0.5 and 5 mg tetraammonium decachloro-mu-oxodiruthenate/L. No effect was observed over the whole test period at any of the tested concentrations. For the definitive test, the highest test level was set at 100 mg/L, which is in line with the criteria of the OECD-guideline regarding the choice of test concentrations.

The concentration of ruthenium in the test solution was analysed at test start and at each renewal in fresh medium and at the respective end of the incubation period (48-hours each). In the freshly prepared test solutions, ruthenium concentrations between 82.6% and 100.0% of the nominal amount were measured. In aged test solutions, ruthenium concentrations were found to range between 51.6 and 113.9% of nominal concentration. Since the measured concentrations were outside a range of 80 to 120% of nominal throughout the test, geometric means of the concentrations measured in fresh and aged test solutions were calculated. As an initial step, the arithmetic mean values of both fresh and aged test solutions were calculated, considering the measured ruthenium concentrations at the test start and at 48 hours and at test end. Measured test item concentrations were calculated based on a ruthenium content of 30.26%.

Nominal concentrations: 5.68, 11.40, 22.70, 45.60 and 100.00 mg/L.
Geometric mean concentrations: 1.34, 3.11, 5.71, 11.32, 22.75 mg ruthenium/L
Corresponding to 4.44, 10.27, 18.87, 37.39 and 75.19 mg tetraammonium decachloro-mu-oxodiruthenate/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: Aquarium
- Material, size, headspace, fill volume: Glass, 12 L with 10 L of test solution
- Aeration: slightly aerated via a glass capillary
- Renewal rate of test solution: test solution replaced after 48 hours
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: purified drinking water (filtered through activated charcoal, passed through a limestone column and aerated)
- Culture medium different from test medium: No
- Intervals of water quality measurement: daily for temperature, pH and dissolved oxygen; ruthenium concentrations at 0, 48 and 96 hours

OTHER TEST CONDITIONS
- Photoperiod: 12 hours light: 12 hours dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality, sub-lethal and behavioural signs recorded at 3, 24, 48, 72 and 96 hours

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 75.19 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

Tetraammonium decachloro-mu-oxodiruthenate

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 22.75 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Remarks:

Ruthenium

Basis for effect:

mortality (fish)

Details on results:

Neither significant signs of disease nor stress (discolouration or abnormal behaviour) were observed up to a concentration of 10.27 mg Tetraammonium decachloro-mu-oxodiruthenate/L (geometric mean) during the test period. Due to the dark colour of the test media at concentrations 18.87 to 75.19 mg/L, it was not possible to adequately observe signs of disease or stress. Fish presented comparable activity to control fish at the water surface. No fish died during the course of the study.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

The study was designed as a semi-static test. Thus, where the test results show inhibition around 50%, they should normally be statistically analysed by Probit analysis, assuming log-normal distribution of the values in order to determine an LC50and LC10value together with 95% confidence intervals. However, no statistical analysis was performed as no mortality was detected throughout the study. Thus, the LC50 is reported as being > as the nominal (or measured) concentration tested.

Validity criteria fulfilled:

yes

Remarks:

Mortality did not exceed 10% in the controls. The dissolved oxygen concentration was ≥60% in test vessels throughout the test.

Conclusions:

The 96 hour LC50 is > 75.19 mg tetraammonium decachloro-mu-oxodiruthenate/L corresponding to >22.75 mg/L ruthenium.

Executive summary:

Zebrafish (Danio rerio) were exposed to the test substance at a range of 5 test item concentrations for 96 hours under semi-static conditions. The test was performed according to OECD guideline 203 and EC method C.1. Mortality and sub-lethal effects (including loss of equilibrium and change in swimming behaviour) were determined after 3, 24, 48, 72 and 96 hours. Test solutions were renewed after 48 hours, and fresh and aged test solutions were analysed by ICP-OES. Based on analysis of ruthenium, test concentrations were outside 80 – 120% of nominal, and therefore geometric mean measured concentrations were used for the reporting of results.

Neither significant signs of disease nor stress were observed at test concentrations up to 10.27 mg tetraammonium decachloro-mu-oxodiruthenate/L.Due to the dark colour of test media at

concentrations 18.87 to 75.19 mg/L, it was not possible to adequately observe signs of disease or stress, but fish near the surface of the water were active. No fish died during the course of the study. The LC50 was determined to be > 75.19 mg tetraammonium decachloro-mu-oxodiruthenate/L, corresponding to > 22.75 mg Ru/L.

Description of key information

The 96 hour LC50 is > 75.19 mg tetraammonium decachloro-mu-oxodiruthenate L-1 corresponding to >22.75 mg Ru L-1.

Additional information

Zebrafish (Danio rerio) were exposed to the test substance at a range of 5 test item concentrations for 96 hours under semi-static conditions (Teigeler 2016). The test was performed according to OECD guideline 203 and EC method C.1. Mortality and sub-lethal effects (including loss of equilibrium and change in swimming behaviour) were determined after 3, 24, 48, 72 and 96 hours. Test solutions were renewed after 48 hours, and fresh and aged test solutions were analysed by ICP-OES. Based on analysis of ruthenium, test concentrations were outside 80 – 120% of nominal, and therefore geometric mean measured concentrations were used for the reporting of results.

Neither significant signs of disease nor stress were observed at test concentrations up to 10.27 mg tetraammonium decachloro-mu-oxodiruthenate L-1.Due to the dark colour of test media at

concentrations 18.87 to 75.19 mg L-1, it was not possible to adequately observe signs of disease or stress, but fish near the surface of the water were active. No fish died during the course of the study. The LC50 was determined to be > 75.19 mg tetraammonium decachloro-mu-oxodiruthenate L-1, corresponding to > 22.75 mg Ru L-1.