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Short-term toxicity to fish

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Endpoint:
short-term toxicity to fish
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Guideline study. No analytical confirmation of test concentrations. Few details regarding test solution preparation.
Justification for type of information:
1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Sodium Tungstate
Target: Ammonium metatungstate
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Qualifier:
according to guideline
Guideline:
OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)
GLP compliance:
not specified
Analytical monitoring:
no
Details on sampling:
N/A
Vehicle:
no
Test organisms (species):
Poecilia reticulata
Details on test organisms:
TEST ORGANISM
- Common name: Guppy
- Strain: No data
- Source: Ward's Natural Science
- Age at study initiation (mean and range, SD): > 4 weeks
- Length at study initiation (length definition, mean, range and SD): No data
- Weight at study initiation (mean and range, SD): No data
- Method of breeding: purchased
- Feeding during test
- Food type: Tetra Min flakes
- Amount: No data
- Frequency: Not fed during 96 h test, twice daily during 14 day test.


ACCLIMATION
- Acclimation period: 4 weeks
- Acclimation conditions (same as test or not): yes
- Type and amount of food: Tetra Min flakes, ad libitum
- Feeding frequency: twice daily
- Health during acclimation (any mortality observed): No mortality 7 days prior to the experiment
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
14 d
Remarks on exposure duration:
96 h test, followed by up to 14 day test with fish that survived the 96 hour one.
Post exposure observation period:
None
Hardness:
no data
Test temperature:
23.5 +/- 0.3 °C
pH:
7.43-8.1 SU
Dissolved oxygen:
3.7-5.49 mg/L
Salinity:
not applicable
Nominal and measured concentrations:
Nominal- Control, 0.75, 1.5, 2.5, 3.75, 5.0, 7.5, and 9.0 g/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: Plastic 8 L aquaria
- Aeration: none
- Type of flow-through (e.g. peristaltic or proportional diluter): semi-static
- Renewal rate of test solution (frequency/flow rate): Initial at 96 hours and then fish placed in entirely new aquaria with fresh solution every 4 days.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: average 0.37 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Local tap water, aged and aerated 3 days before use
- Total organic carbon: No data
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine: No data
- Alkalinity: N/A
- Ca/mg ratio: No data
- Conductivity: 0.399-5.29 mS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: No data


OTHER TEST CONDITIONS
- Adjustment of pH: No data
- Photoperiod: No data
- Light intensity: No data


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, 24 h


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline: N/A
- Range finding study
- Test concentrations: not specified
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
no
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
3.71 g/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
2.06 other: g W/L
Nominal / measured:
nominal
Conc. based on:
other: tungsten concentration
Basis for effect:
mortality (fish)
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
1.54 g/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
0.86 other: g W/L
Nominal / measured:
nominal
Conc. based on:
other: tungsten concentration
Basis for effect:
mortality (fish)
Details on results:
- Behavioural abnormalities: Fish exposed to test substance were slower, and remained predominantly at the bottom of the tank, as compared to controls
- Observations on body length and weight: No data
- Other biological observations: No data
- Mortality of control: No data
- Other adverse effects control: No data
- Abnormal responses: No data
- Any observations (eg precipitation) that might cause a difference between measured and nominal values: No data
- Effect concentrations exceeding solubility of substance in test medium: No data
Results with reference substance (positive control):
N/A
Reported statistics and error estimates:
LC50 values and confidence intervals were calculated individually for each exposure period with the Probit Analysis .Program version 1.5. NOEC and LOEC values were evaluated using ANOVA and one-sided Dunnett's test, Version 1.5. The 5% statistical significance level was accepted for statistical results.
Sublethal observations / clinical signs:

Additional results:

-Wet weight BCF for the test substance was calculated as 0.29 +/- 0.94 L/kg

-Dry weight BCF for the test substance was calculated as 1.57 +/- 0.5 L/kg

Validity criteria fulfilled:
not specified
Conclusions:
The 96 hour LC50 of sodium tungstate to P.reticulata was found to be 3.71 g sodium tungstate/L. The 14 day LC50 was found to be 1.54 g sodium tungstate/L. Confidence intervals were not presented in g/L. The dry weight bioconcentration factor was calculated as 1.57 +/- 0.5 L/kg.
Executive summary:

No short-term toxicity to fish data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to fish data are available on sodium tungstate (source substance), which are used for read-across. Due to similar water solubility and toxicity for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate for this endpoint. In addition, read-across is appropriate because the classification and labelling is similar for the source substance and target substance, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, conservative for the target substance. For more details, refer to the read-across category approach description in the Category section of this IUCLID submission or Annex 3 of the CSR.

Endpoint:
short-term toxicity to fish
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
1991-11-28 to 1991- 12-13
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Conducted according to OECD Guideline 203, and stated GLP, no certificate.
Justification for type of information:
1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Sodium Metatungstate
Target: Ammonium metatungstate
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Deviations:
no
GLP compliance:
yes
Remarks:
Statement, no certificate
Analytical monitoring:
yes
Details on sampling:
- Concentrations: All
- Sampling method: 10 mL-At beginning and end of test
- Sample storage conditions before analysis: Room temperature until shipped for analysis; reserve 25 mL samples frozen at -20 °C for possible analysis.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Each solution prepared separately in DSW. 200, 360, and 640 mg/L were sonicated for 15-25 minutes. These solutions were diluted to 4L with DSW and stirred until dissolved. 560 and 1000 mg/L were treated with ultra-sonication for 45-50 minutes
- Controls: DSW only
- Evidence of undissolved material (eg precipitate, surface film, etc): Precipitate in 1000 mg/L.
Test organisms (species):
Cyprinus carpio
Details on test organisms:
TEST ORGANISM
- Common name: Carp
- Strain: N/A
- Source: Zodiac, proefacc, "De Haar Vissen", L.U. Wageningen, The Netherlands
- Age at study initiation (mean and range, SD): N/A
- Length at study initiation (length definition, mean, range and SD): 2.3 +/- 0.21 cm
- Weight at study initiation (mean and range, SD): 0.24 +/- 0.07 g
- Method of breeding: Purchased
- Feeding during test- not fed during test
- Food type: N/A
- Amount: N/A
- Frequency: N/A

ACCLIMATION
- Acclimation period: 10 days after delivery
- Acclimation conditions (same as test or not): Yes, after a 48 hr setting in period.
- Type and amount of food: Troutvit or Artemia
- Feeding frequency: daily
- Health during acclimation (any mortality observed): <5%

QUARANTINE (wild caught)
- Duration:
- Health/mortality:
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Post exposure observation period:
None
Hardness:
210 mg/L
Test temperature:
Initial temperature 21 °C
Final temperature 22.5 °C
pH:
Range from 7.9 to 8.3
Dissolved oxygen:
> 5 mg/L for all measurements
Salinity:
N/A
Nominal and measured concentrations:
Nominal- 0, 100, 180, 320, 560 and 1000 mg/L.
Analysis revealed that actual concentrations were between 92-95%.
Details on test conditions:
TEST SYSTEM
- Test vessel: Beaker
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: Glass 4 L
- Aeration: constant
- Type of flow-through (eg peristaltic or proportional diluter): N/A
- Renewal rate of test solution (frequency/flow rate): None
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: 0.6 g fish/L
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dutch standard water formulated using Milli-Ro water according to Adema method.
- Total organic carbon: 84.8
- Particulate matter:
- Metals: K-7.8 mg/L; Na- 27.4 mg/L
- Chlorine: 96.6 mg/L
- Ca/mg ratio: Ca-54.4 mg/L; Mg-17.5 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hr
- Light intensity: N/A

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, 24 hr

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Justification for using less concentrations than requested by guideline: N/A
- Range finding study Yes
- Test concentrations: 10-1000 mg/L
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
yes
Remarks:
quarterly
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
420 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Remarks on result:
other: 95% CI 320-560 mg/L
Details on results:
- Behavioural abnormalities: None
- Mortality of control: None
- Effect concentrations exceeding solubility of substance in test medium: 1000 mg/L had precipitate observed.
Results with reference substance (positive control):
- Results with reference substance valid? Yes-for most recent test performed
- Mortality: None in controls
- LC50: between 0.18 and 0.32. Historically, this value is between 0.18 and 1.0
Reported statistics and error estimates:
Calculation method not reported.
Validity criteria fulfilled:
yes
Remarks:
No mortality in controls
Conclusions:
The 96 hour LC50 of the test substance to carp was found to be 420 mg/L, with a 95% confidence interval of 320 to 560 mg/L.
Executive summary:

No short-term toxicity to fish data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to fish data is available on sodium metatungstate (source substance), which are used for read-across. Due to similar water solubility for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate to estimate of potential toxicity for this endpoint. For more details, refer to the read-across category approach description in the Category section of this IUCLID submission or Annex 3 of the CSR.

Endpoint:
short-term toxicity to fish
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
2002-11-04 to 2002-11-21
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Well documented, scientifically sound study that was conducted in accordance with GLP and generally accepted guidelines. The reliability of this study for this substance tested is a K1, but in application of read-across to a different substance, ECHA's guidance specifies that the score can be a maximum of a K2.
Justification for type of information:
1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Ammonium paratungstate
Target: Ammonium metatungstate
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
according to guideline
Guideline:
EU Method C.1 (Acute Toxicity for Fish)
Deviations:
no
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
GLP compliance:
yes
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
- Water solubility: 22 g/L (at 20 °C after 24 h)
Analytical monitoring:
yes
Details on sampling:
no data
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
To accelerate the solution procedure, a five-fold amount of the water solubility of the test substance (5mg/L) under exposure conditions was taken and added to 5 L of dilution water, then treated in an ultrasonic bath for 1 hour and afterwards stirred for 24 h on a magnetic stirrer. Finally undissolved particles of the test substance were removed by filtration using a folded filter of pre size 7-12 um
Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
TEST ORGANISM
- Common name: Zebra fish
- Strain: Danio Rerio
- Source: Aqua KloeGer
- Length at study initiation (length definition, mean, range and SD): Mean standard length (n = 20): 3.64 cm (S.D. = 0.3 cm)

ACCLIMATION
- Acclimation period: Stock held since September 22, 2002 and acclimatised to the test conditions since then.
- Type and amount of food: Commercial fish food, daily. Discontinued 24 hours prior to test.



Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
96 h
Hardness:
173.1 mg/L CaC03
Test temperature:
20.8-21.8 °C
pH:
7.6-7.9
Dissolved oxygen:
8.3-8.5 mg/L (93-97 % saturation)
Salinity:
n/a
Nominal and measured concentrations:
Nominal concentration: 5 mg/L
Measured: 1.1 - 2.9 mg/L (WO3 equivalents)
Measured: 0.86 - 2.3 mg/L (W)
Details on test conditions:
- Test vessels: Glass aquaria holding 5 L of test media
- Experimental design: 1 test concentration (5 mg/L) plus 1 control, 10 animals per test concentration, no feeding during the exposure period, static system
- Photoperiod: 16 hours light, 8 hours dark
- Gentle aeration via narrow glass tubes.
- Biomass loading rate: 0.97 g body weight (wet weight) per litre

The criterion of death used in this study was the absence of response to physical stimulation. In addition to observations on mortality at 2, 24,48, 72 and 96 hours, subjective assessments were made on the type and incidence of sub-lethal effects compared with control fish.
Reference substance (positive control):
no
Duration:
96 h
Dose descriptor:
LC0
Effect conc.:
> 0.86 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: measured Tungsten (W) metal concentration at 96 hours
Basis for effect:
mortality (fish)
Remarks:
and sublethal effects
Duration:
96 h
Dose descriptor:
LC0
Effect conc.:
> 1.1 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: Tungsten trioxide (WO3) concentration at 96 hours
Basis for effect:
mortality (fish)
Remarks:
and sublethal effects
Details on results:
No deaths were observed in either the control or test group throughout the duration of the study.

All results are expressed in terms of mean measured concentrations.

Measured concentrations correspond to 64.7% of nominal values of tungsten trioxide (WO3) at 0 hours, to 14.1% of nominal values of tungsten trioxide (WO3) at 24 hours, to 14.1% of nominal values of tungsten trioxide (W03) at 48 hours, to 14.1% of nominal values of tungsten trioxide (WO3) at 72 hours, and to 14.1% of nominal values of tungsten trioxide (WO3) at 96 hours respectively.

The chemical analysis demonstrated that within the definitive test, compared to the range finding test (5 mg/L), a lower saturation concentration had been reached. Therefore, the recovery values which are calculated on the bases on WO3 and W ion are low. As the test was performed at the water solubility under exposure concentrations, these variations compared to the range finding test were within an acceptable range. Nevertheless the chemical analysis demonstrates that the test substance concentration within the time period 24-96 hours was stable. The concentration dropped below the LOQ, but it was stated by the chemical analyst that the test substance concentration within the time period 24-96 hours was between 0.7-0.9 mg/L. It can be stated that no toxic effects up to the saturation concentration under exposure conditions were observed.

Results with reference substance (positive control):
N/A
Reported statistics and error estimates:
no data
Sublethal observations / clinical signs:

The test was performed using a nominal test substance concentration of 5 mg/L. The test substance contained 89.54% WO3. By the accompanying chemical analysis the respective concentration of tungsten ion has been determined. 100 mg of the test substance contained 71 mg tungsten ion.

Conclusions:
The test substance had no toxic effects up to the saturation concentration under exposure conditions.
Executive summary:

No short-term toxicity to fish data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to fish data are available on ammonium paratungstate (source substance), which are used for read across. Due to similar water solubility for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate to estimate of potential toxicity for this endpoint. For more details, refer to the read-across category approach description in the Category section of this IUCLID submission or Annex 3 of the CSR.

Endpoint:
short-term toxicity to fish
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
2008-09-25 to: 2009-03-13
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Well documented, scientifically sound study conducted in accordance to GLP and OECD guideline 203 with no deviation to the protocol. The reliability of this study for this substance tested is a K1, but in application of read-across to a different substance, ECHA's guidance specifies that the score can be a maximum of a K2.
Justification for type of information:
1. HYPOTHESIS FOR THE CATEGORY APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Sodium Tungstate
Target: Ammonium metatungstate
3. CATEGORY APPROACH JUSTIFICATION: See Annex 3 in CSR
4. DATA MATRIX: See Annex 3 in CSR
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
according to guideline
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
no data
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0 (control), 13, 25, 50, 100, and 200 mg/L; A volume of 10 mL was collected from each control and test substance replicate at 0 and 96 hours and transferred to a culture tube.
- Sampling method: 0.05 mL aliquot of each sample was taken, diluted if necessary with 2% HNO3, capped and shaken to mix.
- Sample storage conditions before analysis: Room temperature
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 7.5075 g of sodium tungstate dihydrate was added to a 21-L glass jar and bringing the jar to a volume of 15,000 mL with blended freshwater. Appropriate aliquots of the primary standard were diluted with 15 L of dilution water to prepare final test concentrations of 13, 25, 50, 100, and 200 mg total product/L. The control solution consisted only of dilution water.
Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
TEST ORGANISM
- Common name: Zebrafish
- Source: Osage Catfisheries, Osage Beach, Missouri
- Age at study initiation (mean and range, SD): Not specified
- Length at study termination (length definition, mean, range and SD): 28-31 mm; mean 30 ± 1.2 mm (Controls only)
- Weight at study termination (mean and range, SD): 0.194-0.408 g; mean 0.276 ± 0.0664 g (Controls only)
- Feeding during test
- Frequency: Not fed during test, or one day prior

ACCLIMATION
- Acclimation period: 5 days
- Acclimation conditions (same as test or not): Temperature adjusted for test
- Type and amount of food: Salmon starter, flake food, and brine shrimp
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): No mortality observed in 14 days prior to testing.



Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Post exposure observation period:
None
Hardness:
140 mg/L CaCO3
Test temperature:
23 ± 1 °C
pH:
8.0-8.3 SU
Dissolved oxygen:
6.7-8.3 mg/L (82 to 101% sat)
Salinity:
Not applicable
Nominal and measured concentrations:
Nominal- 0 (control), 13, 25, 50, 100, and 200 mg/L.
Mean calculated-
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 21 L glass jars, covered with plastic Petri dishes; 15 L test solution.
- Aeration: None
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.18 g fish tissue/L test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Moderately hard freshwater made with naturally hard well water blended with well water demineralized by reverse osmosis, total hardness of 130-160 mg/L CaCO, passed through a sediment filter prior to use.
- Metals: B-0.415 mg/L, Ca-83.1 mg/L, Mg- 33.1 mg/L, K-7.93 mg/L, Na-32.2 mg/L; all others below DL.
- Pesticides: Below DL
- Alkalinity: 150 mg/L CaCO3
- Conductivity: 328 uS
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16h light/ 8h dark, with 30 min simulated dawn and dusk periods
- Light intensity: 542 lux at initiation of the definitive test as measured with a LI COR Model LI-189 light meter equipped with a photometric sensor.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, 24h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2x
- Range finding study: Other studies indicated a low potential for toxicity to aquatic organisms; Therefore, a range finding study was not performed. Definitive testing was performed at a level that exceeds the guideline-required maximum, 100 mg/L for this test.
Reference substance (positive control):
no
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Remarks on result:
other: No mortality in any control or test solution
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 181 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Remarks:
based on mean calculated concentrations of sodium tungstate
Basis for effect:
mortality (fish)
Remarks on result:
other: No mortality in any control or test solution
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
200 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
behaviour
Remarks on result:
other: Lack of mortality and sublethal effects
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
>= 181 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Remarks:
based on mean calculated concentrations of sodium tungstate
Basis for effect:
behaviour
Remarks on result:
other: Lack of mortality and sublethal effects
Details on results:
Biological Results:
After 96 hours of exposure, there was no mortality in the 0 (control) or any of the test substance treatments. There were no sublethal observations during the exposure. The estimated 24-, 48-, 72-, and 96-hour LC50 values for zebrafish exposed to sodium tungstate dihydrate were >200 mg/L, the highest concentration tested. Since there was no partial response, the 96-hour slope of the concentrations-response line could not be calculated from the probit analysis. The 96 hour no-observed-effect concentration (NOEC) was 200 mg/L based on the lack of mortality and sublethal effects atthis and lower test substance concentrations.
Reported statistics and error estimates:
Estimates of LC50 values and their 95% confidence limits were calculated using the probit method and Trimmed Spearman-Karber method. When the p value for Goodness of Fit was >0.05 and there was no other evidence of questionable convergence, the probit method was selected for reporting. When this criterion was not achieved, the Trimmed Spearman-Karber method was selected for reporting. The no observed-effect concentration (NOEC) was determined based on the absence of any mortality or sublethal effects.
Conclusions:
Based on nominal concentrations, the estimated 96 hour LC50 value for zebrafish exposed to sodium tungstate dihydrate was >200 mg/L, the highest concentration tested. The 96 hour slope of the concentrations-response line could not be calculated. The 96-hour no-observed-effect concentration (NOEC) was 200 mg/L, based on the lack of mortality and sublethal effects at this and the lower concentrations.
Executive summary:

No short-term toxicity to fish data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to fish data is available on sodium tungstate (source substance), which are used for read-across. Due to similar water solubility and toxicity for the target substance compared to the source substance, the resulting read-across from the source substance to the target substance is appropriate for this endpoint. In addition, read-across is appropriate because the classification and labelling is similar for the source substance and target substance, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, conservative for the target substance. For more details, refer to the read-across category approach description in the Category section of this IUCLID submission or Annex 3 of the CSR.

Description of key information

The short-term toxicity of ammonium metatungstate to fish is estimated based on read-across from sodium tungstate. In a 96-h static test on ammonium paratungstate with Danio rerio (zebrafish), no toxic effects up to the saturation concentration of sodium metatungstate were observed. Therefore, the LC50 could not be ascertained. In a static test using Cyprinus carpio (common carp) and testing sodium metatungstate the 96-h LC50 was found to be 420 mg sodium metatungstate/L (ca. 263 mg W/L). Two 96-h assays are available for sodium tungstate testing Danio rerio (zebrafish) in a static assay and Poecilia reticulata (guppy) in a semi-static assay, which report 96-h LC50 values of >181 mg sodium tungstate/L (ca. 106 mg W/L) and 3.71 g sodium tungstate/L (2.06 g W/L), respectively.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish
Effect concentration:
106 mg/L

Additional information

No short-term toxicity fish toxicity data of sufficient quality are available for ammonium metatungstate (target substance). However, short-term fish toxicity data are available for ammonium paratungstate, sodium metatungstate and sodium tungstate (source substances), which were evaluated for read-across.

 

Due to similar or lower transformation/dissolution results for the target substance than the source substances, the resulting toxicity potential is expected to be similar or lower, so read-across is appropriate. In addition, read-across is justified because the classification and labelling is the same or less severe for the target substance and the PBT/vPvB profile is the same. Finally, the dose descriptors are, or are expected to be, sufficiently similar or higher for the target substance, and read-across to the source substancess are adequately protective. For more details, refer to the read-across category approach description in the Category section of this IUCLID submission or Annex 3 of the CSR.