Rhodium trinitrate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

All test concentrations sampled at 0 and 24 hours. Concentration of stock solution determined at 0 hours.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 1 g/L test solution prepared in synthetic freshwater was used as a stock solution.
- Controls: Blank control included
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): Not reported

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna STRAUS (CLONE 5)
Source: Organisms received from Bayer AG, Leverkusen, Germany in 1991 and bred in house.
Holding: Maintained in M4 medium in 1L beakers with Desmodesmus subspicatus feed. Conditions support parthenogenetic reproduction.
Age: Only < 24 h old offspring used in test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg CaCO3/L

Test temperature:

20.4°C (mean)
20.3 - 20.6°C

pH:

3.3 - 8.3
pH values in the 11, 17 and 91 mg/L test concentrations were 6.1 - 7.8
pH values in the 164, 336 and 658 mg/L test concentrations were 3.3 - 5.0

Dissolved oxygen:

8.1 - 8.8 mg/L

Nominal and measured concentrations:

Nominal: 20, 40,80, 160, 320 and 640 mg/L
Measured at 0h: 17, 31, 87, 160, 338 and 644 mg/L
Measured at 48h: 7.2, 9.8, 95, 168, 336, 672 mg/L
Geometric mean measured: 11, 17, 91, 164, 336, 658 mg/L
Geometric mean measured concentrations were used for biological evalation.

Details on test conditions:

Exposure medium: Synthetic freshwater.
Test vessel: Round bottomed test tubes calibrated to 10 mL
Aeration: none.
Number of organisms per vessel: 5
Number of replicates: 4
Photoperiod: dark
Feeding: None during test

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

120 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Concentration range was 91 - 164 mg/L.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

122 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Concentration range was 91 - 164 mg/L.

Details on results:

5% immobilisation at 91 mg/L at 48 hours, 100% immobilisation at 164 mg/L at 48 hours. EC50 values determined graphically.

Results with reference substance (positive control):

Positive control showed that the sensitivity of the organisms lay within the normal range.

Validity criteria fulfilled:

yes

Remarks:

< 10% of control organisms had been immobilised or trapped at the surface of the water. DO concentration was > 60% of air saturation value at the temperature used. Geometric mean measured concentrations after 0 and 48 h used for test evaluation.

Conclusions:

The 48h EC50 for rhodium (III) nitrate hydrate is 120 mg/L.

Executive summary:

Enste-Diefenbach (2003) is a GLP compliant study following OECD guideline 202. Four replicates of five organisms were used for each test concentration and the control. Test concentrations were analysed and as they deviated by more than 20% from nominal in some concentrations mean measured concentrations were used for reporting of results. pH in the highest three test concentrations ranged from 3.3 – 5.0 and is likely to have had an impact on the study results. The study followed a standard test guideline but there are limitations, particularly due to the pH of the test solutions for the higher concentrations, therefore it is assigned a Klimisch score of 2 (reliable with restrictions).

The 48h EC50 for rhodium (III) nitrate hydrate is 120 mg/L.

Description of key information

The 48h EC50 for rhodium (III) nitrate hydrate is 120 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

120 mg/L

Additional information

Enste-Diefenbach (2003) is a GLP compliant study following OECD guideline 202. Four replicates of five organisms were used for each test concentration and the control. Test concentrations were analysed and as they deviated by more than 20% from nominal in some concentrations mean measured concentrations were used for reporting of results. pH in the highest three test concentrations ranged from 3.3 – 5.0 and is likely to have had an impact on the study results. The study followed a standard test guideline but there are limitations, particularly due to the pH of the test solutions for the higher concentrations, therefore it is assigned a Klimisch score of 2 (reliable with restrictions).

The 48h EC50 for rhodium (III) nitrate hydrate is 120 mg/L.