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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Remarks:

The study was done to characterize the toxicity of Vanadium in terms of its oxidation states to two groups of microbial species (bacterial and protozoan isolates). Tolerance limit and removal ability was investigated.

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V3+ (24h median)

Effect conc.:

2 666.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for Pseudomonas putida

Remarks:

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V4+ (24h median)

Effect conc.:

>= 1 572.5 - <= 1 709.2 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for Pseudomonas putida

Remarks:

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V5+ (24h median)

Effect conc.:

>= 1 230.6 - <= 1 367.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for Pseudomonas putida

Remarks:

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V3+ (24h median)

Effect conc.:

>= 752.1 - <= 820.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for protozoa isolate Peranema sp.

Remarks:

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V4+ (24h median)

Effect conc.:

>= 1 039.9 - <= 1 162.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for protozoa isolate Peranema sp.

Remarks:

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

Duration:

24 h

Dose descriptor:

other: LC50

Remarks:

value for V5+ (24h median)

Effect conc.:

>= 1 093.9 - <= 1 367.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

converted to VAA

Basis for effect:

other: Mortality

Remarks on result:

other: Result for protozoa isolate Peranema sp.

Remarks:

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

Details on results:

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:
- Adsorption (e.g. of test material to the walls of the test container):
- Blank controls oxygen uptake rate:
- Coefficient of variation of oxygen uptake rate in control replicates:

Reported statistics and error estimates:

Data were statistically analysed using the Stata computer software (version: STATA V10, STATA Corp. LP, 2009). The difference between phystcochemical parameters and also growth performance, tolerance limit over the oxidation states was analysed using the one-way analysis of variance (ANOVA). The tests for relationships were carried out using the Pearson correlation index and the iinerpreianon was performed at a two-sided 95% confidence limit.

In conclusion, the toxicity of Vanadium (V) in its different oxidation slates to selected bacterial species was assessed and compared with those of protozoan isolates. The outcome of Ihis study revealed that an increase in vanadium oxidation states stimulates a further increase in toxicity of the test metal on bacterial isolates, whereas its toxicity on protozoan isolates decreases. The study has also demonstrated the ability of Pseudomonas putida to reduce V5 +, V4 + and V3 + to V2 + in the modified mixed liquor. Based on scientific evidence that V5 + is more toxic than other V (+2, +3 and +4) to humans and other animals, the ability of Pseudomonas putida to reduce V5 +, V4 + and V3 + to V2 + showed that this isolate is a potential candidate for the reduction of the toxicity of V in water and can be used in the remediation of V-polluted wastewater system. Further investigations are needed to delineate components required in the electron transport chain that are needed for V (+5, +4, +3) reduction.

Validity criteria fulfilled:

not applicable

Reference 2

Endpoint:

toxicity to microorganisms, other

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

Duration:

24 h

Dose descriptor:

other: Toxicity threshold (TT)

Effect conc.:

67 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: The Toxicity Threshold is defined as the pollutant concentration at which the onset of inhibitory action is observed.

Remarks on result:

other: Result for Pseudomonas putida,

Remarks:

Acetylacetone (IUPAC name: 2,4 -pentandione; CAS No. 123-54-6)

Duration:

24 h

Dose descriptor:

other: Toxicity threshold (TT)

Effect conc.:

11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: The Toxicity Threshold is defined as the pollutant concentration at which the onset of inhibitory action is observed.

Remarks on result:

other: Result for Entosyphon sulcatum

Remarks:

Acetylacetone (IUPAC name: 2,4 -pentandione; CAS No. 123-54-6)

Details on results:

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No such observations.
- Effect concentrations exceeding solubility of substance in test medium: No.
- Adsorption (e.g. of test material to the walls of the test container): Not observed.
- Blank controls oxygen uptake rate: Not reported.
- Coefficient of variation of oxygen uptake rate in control replicates: Information not available.

Results with reference substance (positive control):

No reference substance was used. However, the study comprise investigation of 156 chemical compounds for their acute toxicity to algae. Hence the plausibility of results for the test compound could be compared with the observed toxicity of the other chemicals.

Reported statistics and error estimates:

No statistical procedures reported for Pseudomonas (bacteria) results. Regarding the results of the protozoa (Entosiphon) counting, results were evaluated as follows: The For mathematical evaluation of toxtcologtcal findings at the end of the test period, the mean value (A) of impulses/mL in test cultures free from toxic influence or non-stimulated test cultures is calculated, provided the counts are within a standard deviation range of <5%. The term "counts" corresponds to impulses indicated by ibe coulter counter. The mean value (B) of counts performed in test cultures of the lowest toxic pollutant concentration of the dilution series are also calculated. As coordinates, (a) (highest non-toxic pollutant concentration) over (A) and (b) (lowest toxic pollutant concentration) over (B) are entered into a suitable electronic calculator. After having entered (A - 5%), the pollutant concentration at which inhibitory action begins (c) may be obtained from the regression line between (a;A) to (b;B).

Validity criteria fulfilled:

not specified

Conclusions:

The 24 hour TT-values (toxicity threshold) values of 156 substances hazardous for bacteria species Pseudomonas putida and protozoa Entosiphon sulcatum were determined by means of a standardized procedure (Cell Multiplication Inhibition Test) under static conditions. The Toxicity Threshold is defined as the pollutant concentration at which the onset of inhibitory action is observed. For Acetylacetone (IUPAC name: 2,4 -pentandione; CAS No. 123-54-6) following Toxicity Threshold (TT) was determined:  TT = 67 mg/L for Pseudomonas putida and 11 mg/L for Entosiphon sulcatum (nominal concentrations).

Executive summary:

The TT-values (toxicity threshold) values of 156 hazardous substances were determined for Pseudomonas putida (bacteria) and Entosiphon sulcatum (protozoa) by means of a standardized procedure (Cell Multiplication Inhibition Test). The test was performed under static conditions with an exposure period of 24 hours. The Toxicity Threshold is defined as the pollutant concentration at which the onset of inhibitory action is observed. One of the investigated chemicals was Acetylacetone (IUPAC name: 2,4 -pentandione; CAS No. 123-54 -6), a degradation product of Vanadium-(III)-acetylacetonate.
This work has contributed to the creation of a scientific basis for corresponding legislation. Pure cultures of single-cell model organisms were used in the test. Culture media and conditions for the preparation of stock cultures, preliminary cultures, and test cultures of the model organisms were standardized, Inoculum, cell multiplication, and its inhibition were determined quantitatively. The present study of the potential toxic action of water pollutants on water micro-organisms has been performed with special reference to the toxicity for model organisms of biological self-purification by determining the toxicity thresholds (TT) for Pseudomonas putida (bacteria), Scenedesmus quadricauda (green algae) and Entosiphon sulcatum (protozoa). As test medium artificial freshwater was prepared by adding of specific nutrient solutions. Dilution series of the chemical compounds were prepared by dilution of a stock solution with sterile double-distilled tap water. These dilutions each contain 1 part (v/v) of pollutant solution in 2.0E+0 to 2.0E+14 parts (v/v) mixture.

Bacteria part of the study:
The multiplication of bacterial cells of the genus Pseudomonas is inhibited by dissolved toxic water ingredients. After a certain period the increase in the number of cells in a test culture free from toxic influence and with a defined standardized offer of nutrients will exceed that observed in a test culture containing dissolved toxic substances and kept under identical conditions. The concentration of the bacterial suspension is measured turbidimetrically (while diffused light is screened off); it is expressed by the extinction of the primary light or the monochromatic radiation at 436 nm for a layer of 10 mm thickness. The concentration at which the inhibitory action of a pollutant starts will be present in that step of a dilution series of the pollutant having an extinction value at the end of the test period that is >=3% below the mean value of extinction for non-toxic dilutions of the test cultures.

Protozoa part of the study:
Dissolved toxic water ingredients will inhibit cell multiplication of the protozoa, Entosiphon sulcatum. Thus, in a test culture containing dissolved toxic substances the count of organisms, after a certain period, will be less than in a test culture kept under identical conditions, however, free from toxic influence. The number of protozoa is determined by means of a cell counter.

Results: From the number of 156 inorganic and organic pollutants tested, 23 exhibited a pronounced selective toxic action on bacteria or the species Pseudomonas putida, 47 on algae of the species Scenedesmus quadricauda, and 43 on flagellate protozoa of the species Entosiphon sulcatum. For Acetylacetone (IUPAC name: 2,4 -pentandione; CAS No. 123-54-6) following Toxicity Threshold (TT) was determined:  TT = 67 mg/L for Pseudomonas putida and 11 mg/L for Entosiphon sulcatum (nominal concentrations). TT is defined as pollutant concentrations at which the onset of inhibitory action was observed.

Description of key information

The parent compound Vanadium-tris-acetylacetonate is rapidly hydrolysed to 2,4 -pentanedione (CAS no. 123 -54 -6) and Vanadyl acetylacetonate (CAS no. 3153 -26 -2) in the presence of water (> 80% hydrolysis after 1h at pH 1.2, 4, 7 and 9). Hence, the half life is e.g. max. 1/48 of the test duration when put into aqueous test systems (e.g. daphnia (48 h test duration) or algae (72 h test duration) acute toxicity tests). Accordingly, the substance as such does not need to be tested in those systems and reliable data gained with the hydrolysis products 2,4-Pentadione (Cas no. 123-54-6) and Vanadyl acetylacetonate (3153-26-2) or comparable inorganic Vanadium compounds are used to adress the endpoint, which is entirely appropriate to draw conclusions on the toxicity of Vanadium-tris-acetylacetonate to microorganism.

Pseudomonas putida, static, freshwater, VCl₃, LC50 (24 h) = 390 mg V³⁺/L - VAA LC50 (24 h) = 2666.4 mg VAA/L

Peranema sp., static, freshwater, VCl₃, LC50 (24 h) = 110 - 120 mg V³⁺/L - VAA LC50 (24 h) = 752.1 - 820.4 mg VAA/L

Pseudomonas putida, static, freshwater, VCl₄, LC50 (24 h) = 230 - 250 mg V⁴⁺/L - VAA LC50 (24 h) = 1572.5 - 1709.2 mg VAA/L

Peranema sp., static, freshwater, VCl₄, LC50 (24 h) = 160 - 170 mg V⁴⁺/L - VAA LC50 (24 h) = 1039.9 - 1162.3 mg VAA/L

Pseudomonas putida, NaVO₃, static, freshwater, LC50 (24 h) = 180 - 200 mg V⁵⁺/L - VAA LC50 (24 h) = 1230.6 - 1367.4 mg VAA/L

Paranema sp., NaVO₃ static, freshwater, LC50 (24 h) = 160 - 200 mg V⁵⁺/L - VAA LC50 (24 h) = 1093.9 - 1367.4 mg VAA/L

Pseudomonas putida, 2,4 -pentanedione, static, freshwater, Toxicity Threshold (24 h) = 67 mg/L

Entosyphon sulcatum, 2,4 -pentanedione, static, freshwater, Toxicity Threshold (24 h) = 11 mg/L

Key value for chemical safety assessment

EC50 for microorganisms:

752.1 mg/L