Tris(pentane-2,4-dionato-O,O')vanadium

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Remarks:

Chronic toxicity to Daphnia (23 d exposure)

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

please refer to Read-across statement attached in section 13

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

please refer to Read-across statement attached in section 13

Key result

Duration:

23 d

Dose descriptor:

LC50

Remarks:

converted to VAA

Effect conc.:

13.7 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

reproduction

Remarks on result:

other: for details on the calculation please refer to 'Overall remarks'

Duration:

23 d

Dose descriptor:

other: NOLC

Remarks:

No Observed Lethal Concentration)

Effect conc.:

10.9 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

reproduction

Remarks on result:

other: for details on the calculation please refer to 'Overall remarks'

Duration:

23 d

Dose descriptor:

other: MATC

Remarks:

Maximum Acceptable Toxicant Concentration (basd on reproduction)

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

reproduction

Remarks on result:

other: for details on the calculation please refer to 'Overall remarks'

Details on results:

- Behavioural abnormalities: No.
- Observations on body length and weight: No.
- Other biological observations: None
- Mortality of control: During chronic testing control mortality did not exceed 10%.
- Other adverse effects control: Not observed.
- Abnormal responses: Not observed.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No.
- Effect concentrations exceeding solubility of substance in test medium: Not relevant.

Results with reference substance (positive control):

No reference substance investigated.

Reported statistics and error estimates:

The 48-h, 96-h, 168-h and 23-days LC50 and EC50 values are obtained using the graphical method of Litchfield and Wilcoxon (1949).
Litchfield, J.T. and Wilcoxon, F. (1949): A simplified method of evaluating dose-effect experiments. J Pharm Exp Ther 96, pp. 99-113.

From the life-cycle test with Daphnia magna, it appears that vanadium induced mortality rather impairment of reproduction. The similarity between the NOLC values derived from the chronic and acute tests points to a direct toxic action of vanadium on daphnids, rather than by accumulation. A "safe" level of vanadium for Daphnia magna is estimated to be about 1.6 mg V/L. This level is much higher than the vanadium concentrations normally found in freshwater.

Validity criteria fulfilled:

not applicable

Conclusions:

Chronic toxicity of sodium metavanadate to aquatic invertebrate Daphnia magna was determined under semi-static conditions (23 d exposure). Results (based on reproduction): LC50 (23d) = 2.0 mg V/L (CI: 1.9-2.2 mg V/L), NOLC (No Observed Lethal Concentration, 23d) = 1.6 mg V/L. MATC (Maximum Acceptable Toxicant Concentration) based on reproduction, amounts to 1.9 mg V/L.

Executive summary:

Chronic toxicity of sodium metavanadate to aquatic invertebrate Daphnia magna was determined under semi-static conditions. Beside reproduction, the monitored end-points are mortality, as determined by lack of movement of antennae or post-abdominal claw on gentle prodding and complete immobilization as determined by unability of swimming for 15 seconds after gentle agitation of the test container. Toxicity parameter were determined after an exposure period of 23 days. Reproduction was assessed by counting and discarding young produced each time the parent animals are transferred during the second week, and daily during the last week of the test. Nine vanadium concentrations are selected for testing . Adult survival , time to the first brood, young per female per day and the number of 'eggs' and newborns produced by the adull daphnids are the parameters monitored during these tests. The test medium was changed on days 2, 5, 7, 9, 12, 14, 16, 19 and 21. Beside LC50 also NOLC (No Observed Lethal concentrations) was calculated. Considering reproduction, a MATC value (Maximum Acceptable Toxicant Concentration) was determined. In general, the measured vanadium concentrations correspond within 10% of the initial amount of the metal added to each test container. Therefore, all effect concentrations are reported in terms of the nominal vanadium concentrations. A control and at least five vanadium concentrations are selected on the basis of a logarithmic expansion. No details about tested concentration range reported.

Results (all concentrations in mg V/L, average results of 4 test runs): Preliminary chronic tests indicated that concentrations up to 1.6 mg V/L did not inhibit the reproduction of the daphnids. Following reproduction-based effect concentrations were obtained in the main study: LC50 (23d) = 2.0 mg V/L (CI: 1.9-2.2 mg V/L), NOLC (No Observed Lethal Concentration, 23d) = 1.6 mg V/L. MATC (Maximum Acceptable Toxicant Concentration) based on reproduction amounts to 1.9 mg V/L.

The 23-days LC50 is only about half of the 48-h LC(EC)50 values which suggests that vanadium has no long-term toxic effect on the daphnids.

Description of key information

Daphnia magna, semi-static, freshwater, NOLC (23 d) = 1.6 mg V/L - VAA NOLC (23 d) = 10.9 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10.9 mg/L