Ruthenium trichloride hydrate

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

Study period:

11 July - 15 July 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

-Sampling: Samples of the test solution were taken at test start (fresh solutions), after 48 hours (aged and fresh solutions), and at test end (aged solutions). From each sample, two aliquots of 20 mL were taken, from which one was used for analysis and one served as retain sample. Samples of freshly prepared test solution were taken directly after filtration (0.2 μm PES Bottle Top Filter), aged samples were filtered again before acidification with HNO3.
- Sample storage conditions before analysis: All samples were acidified with 2.5 mL HNO3 for stabilization and stored at 4 °C until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test solution was prepared by weighing an appropriate amount of RuCl3, adding it to the pH-adjusted dilution water and stirring it for 1 hour. After stirring, the pH of the test solution was measured and readjusted to pH 6. Afterwards, the test solution was filtered via a 0.2 μm bottle top filter (polyethersulfone; PES) in order to remove any insoluble material before application in the test.

- Controls: Dilution water of pH 6

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Source: Test facility bred
- Length at study initiation (length definition, mean, range and SD): mean: 1.7 cm, range: 1.5 - 2.0 cm (min - max)
- Weight at study initiation (mean and range, SD): mean: 0.083 g, range: 0.055 - 0.100 g (min - max)
- Maintenance of the brood fish: The fish were held in water of the same quality as used in the test (purified drinking water)

ACCLIMATION
- Acclimation period: at least 12 days
- Acclimation conditions (same as test or not): yes
- Type and amount of food during acclimation: live brine shrimp (Artemia salina) nauplii ad libitum, and ground flake food TetraMin® (Tetra Werke, Melle, Germany) once daily
- Health during acclimation (any mortality observed): Only healthy fish without diseases and abnormalities were used in the study. Mortality of the batch was less than 5 % in the week preceding the start of the study.


FEEDING DURING TEST: No feeding occurred during the test as well as 24 h before test start.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

1.2 mmol/L

Test temperature:

22.9 and 23.0°C

pH:

6.00 and 7.05

Dissolved oxygen:

88 % and 93 %

Salinity:

N/A

Conductivity:

253 μS/cm

Nominal and measured concentrations:

Range finder test:
Nominal: 1, 10 and 100 mg test item/L, corresponding to 0.41, 4.06 and 40.56 mg Ru/L.
Definite test:
Nominal: 10 mg test item/L, corresponding to of 4.06 mg Ru/L.
Measured: 0.38 mg Ru/L, 0.94 mg test item/L (geometric means of initial and aged measured concentrations)

The test concentrations were evaluated at test start, at test item renewal after 48 h of aged and fresh solution, and at test end. The mean measured concentration of ruthenium in freshly prepared test solution was 0.92 mg/L (22.6 % of nominal loading). In aged test solutions, the mean measured ruthenium concentration was 0.16 mg/L. Consequently, the ruthenium concentration decreased considerably to 3.92 % of nominal loading, corresponding to 17.31 % of the initial Ru concentration. The geometric mean of initial and aged measured concentrations was 0.38 mg/L, corresponding to 9.42 % of the nominal loading of ruthenium.

Measured concentrations were not in the required ± 20 %-range of nominal test concentrations. Therefore, results were based on the mean measured value (geometric mean).

Details on test conditions:

TEST SYSTEM
- Test vessel: full glass beakers of 2.5 L, containing 2.0 L of test solution
- Aeration: yes, slightly aerated via glass capillaries
- Renewal rate of test solution (frequency): after 48 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: mean weight resulted in a loading of 0.416 g/L test medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Purified tap water was used according to the OECD guideline 203. The purification included filtration with activated charcoal and aeration.
- NPOC (Non purgeable organic carbon): 0.9 mg/L
- Metals: The following metals (cadmium, chrome, copper, iron, manganese, nickel, lead, and zinc) were below the limit of quantification.
- Alkalinity: 1.8 mmol/L

- Culture medium different from test medium: no
- Intervals of water quality measurement: pH, temperature and dissolved oxygen were measured daily
OTHER TEST CONDITIONS
- Adjustment of pH: yes, adjusted to pH 6 by addition of an appropriate amount of concentrated HCl
- Photoperiod: 12/12 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and abnormal behaviour was recorded after 24 h, 48 h, 72 h and 96 h. Dead animals (no visible movement, e.g. gill movement) were eliminated from the vessels as soon as they were discovered. Abnormal behaviour includes e.g. loss of equilibrium, swimming behaviour, respiratory function, and altered pigmentation.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.38 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.94 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No effects concerning any disease, stress like discoloration, swimming behaviour or orientation in the water phase due to ruthenium were observed
- Mortality of control: No fish was found dead during the course of the test in the control
- Other adverse effects control: None observed

Reported statistics and error estimates:

No Lethal Concentrations (LCx) was calculated at test end since there was no observed mortality during the test.

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 to zebrafish is > 0.94 mg test item L-1 (>0.38 mg Ru L-1), based on geometric mean measured concentrations.

Executive summary:

A limit test to determine the acute toxicity of Ruthenium (III) chloride hydrate to zebrafish (Danio rerio) was performed according to the OECD guideline 203 and the EEC method C.1 (Muth-Kohne 2016).

Based on the results from a rangefinder test, the fish were exposed to one nominal concentration of 10 mg test item L-1, corresponding to a nominal ruthenium concentration of 4.06 mg L-1 under semi-static conditions for 96 hours. Test media was renewed after 48 hours. Untreated dilution water was run in parallel as a control. Ten fish were placed in the treatment vessel and in the control. Effects on survival were determined after 24, 48, 72 and 96 hours. ICP-OES was used to analyse test solutions and as measured concentrations were not within 20% of nominal the effect assessment was based on geometric mean measured concentrations of aged and fresh test solutions.

No mortality or any behavioural effects were observed at any observation time. Thus, the LC50 was determined to be > 0.94 mg test item L-1 (>0.38 mg Ru L-1), based on geometric mean measured concentrations.

Description of key information

The 96-hour LC50 to zebrafish is > 0.94 mg test item L-1 (>0.38 mg Ru L-1), based on geometric mean measured concentrations.

Additional information

A limit test to determine the acute toxicity of ruthenium (III) chloride hydrate to zebrafish (Danio rerio) was performed according to the OECD guideline 203 and the EEC method C.1 (Muth-Kohne 2016).

Based on the results from a rangefinder test, the fish were exposed to one nominal concentration of 10 mg test item L-1, corresponding to a nominal ruthenium concentration of 4.06 mg L-1 under semi-static conditions for 96 hours. Test media was renewed after 48 hours. Untreated dilution water was run in parallel as a control. Ten fish were placed in the treatment vessel and in the control. Effects on survival were determined after 24, 48, 72 and 96 hours. ICP-OES was used to analyse test solutions and as measured concentrations were not within 20% of nominal the effect assessment was based on geometric mean measured concentrations of aged and fresh test solutions.

No mortality or any behavioural effects were observed at any observation time. Thus, the LC50 was determined to be > 0.94 mg test item L-1 (>0.38 mg Ru L-1), based on geometric mean measured concentrations.