Hexaammonium wolframate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

2002-10-24 to: 2002-10-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Well documented, scientifically sound study performed in accordance with GLP and the Commission Directive 92/69/EEC. The test method was similar to OECD guideline 202. 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.2 (Acute Toxicity for Daphnia)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility (under test conditions): 22 g/L (20 °C after 24 h)

Analytical monitoring:

yes

Details on sampling:

no data

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: To produce the only test concentration 105.5 mg of the test substance were added to 1 L of dilution water, then treated in an ultrasonic bath for 1 hour and afterwards stirred for 24 hours on a magnetic stirrer. Finally, undissolved particles of the test substance were removed by filtration using a folded filter of pore size 7-12 um.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water Flea
- Source: Bundesgesundheitsamt, Berlin

ACCLIMATION
- Acclimation period: A population of parthenogenetic females of synchronized age structure is maintained since more than 15 years in the test facility.
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: Unicellular green algae (Desmodesmus subspicatus)
- Feeding frequency: ad libitum
- Health during acclimation (any mortality observed): Mortalities of parent Daphnia during the culture period are recorded daily in a semi-quantitative way. The neonates are separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

273.1 mg/L CaCO3

Test temperature:

mean +/- 1 °C (18-22 °C)

pH:

7.7

Dissolved oxygen:

8.8 mg/L

Salinity:

n/a

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured (WO3): 0-hr (7.8 mg/L); 48-hr (3.5 mg/L)
Measured (W): 0-hr (6.2 mg/L); 48-hr (2.8 mg/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beaker
- Material, size, headspace, fill volume: 50 mL holding 10 neonates in 20 mL of test medium.
- No. of organisms per vessel: 10 neonates
- No. of vessels per concentration (replicates): 2 replicates
- No. of vessels per control (replicates): 2 replicates
- No. of vessels per vehicle control (replicates): 2 replicates

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: > 1000 lux

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

> 4.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: dissolved tungsten ion concentration

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

> 5.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: tungsten trioxide concentration

Basis for effect:

mobility

Details on results:

No adverse effects were observed in either the control group or the test group for the duration of the test.

Results are expressed in terms of mean measured concentrations. Measured concentrations corresponded to 8.7% of nominal values of tungsten at 0 hours, and to 3.9% of nominal values of tungsten at 48 hours, respectively.

Results with reference substance (positive control):

n/a

Reported statistics and error estimates:

no data

Chemical analysis of the test substance demonstrated that 100 mg of the test substance contained 71 mg tungsten.

Conclusions:

No adverse effects were seen during the duration of the test up to the saturation concentration of the test substance.

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.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

1991-11-20 to 1992-08-09

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study was conducted according to OECD Guideline 202 (adopted 1984) and GLP. However, when compared to the current OECD 202 guideline, the study's use of M4 media containing EDTA is not recommended for metal-containing test substances; no analytical measurements to support nominal test substance concentrations; 10 animals were grouped per vessel instead of recommended 5; some experimental details, such as dilution water parameters, not reported. The reliability of this study for the substance tested is a K2; in application of read-across to a different substance ECHA’s guidance specifies that the score can be a maximum of 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 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 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted April 1984. The guideline has since been updated (April 2004).

Deviations:

yes

Remarks:

Use of M4 media containing EDTA is not recommended for metal-containing test substances; no analytical measurements to support nominal test substance concentrations; 10 animals were grouped per vessel instead of recommended 5; missing details.

GLP compliance:

yes

Remarks:

Statement, no certificate

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no data

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 992.9 mg test substance was added to 1000 mL M4 medium and sonicated to dissolve.
- Controls: M4 media only
- Evidence of undissolved material (eg precipitate, surface film, etc): none

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna or water flea
- Strain: Straus
- Source: in-house culture
- Age at study initiation (mean and range, SD): <24 h
- Method of breeding: parthanogenic
- Feeding during test: no
- Food type: not fed during test
- Frequency: n/a

ACCLIMATION
- Acclimation period: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

No data

Test temperature:

Range: 17.5-19.5 °C

pH:

7.9 to 8.1 SU

Dissolved oxygen:

9.3-9.5 mg/L

Nominal and measured concentrations:

Nominal: 0, 18, 32, 56, 100, 320, 560 mg/L
Results were based on nominal concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 250 mL glass
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h per day


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

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study: yes
- Test concentrations: 0.1-1000 mg/L with a geometric progression of 10.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

261 mg/L

Nominal / measured:

nominal

Conc. based on:

other: concentration of sodium metatungstate

Basis for effect:

other: immobility, including mortality

Remarks on result:

other: 95% CI is 206-345 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

83.4 mg/L

Nominal / measured:

nominal

Conc. based on:

other: concentration of sodium metatungstate

Basis for effect:

other: immobility, including mortality

Remarks on result:

other: 95% CI is 70.5-97.7 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

other: concentration of sodium metatungstate

Basis for effect:

other: immobility, including mortality

Details on results:

No data.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Mortality: No mortality in controls
- EC50/LC50: 24 hr EC50: 1.58 mg.L; 48 hr EC50: between 0.56 and 1.0 mg/L. Both within expected ranges for validity.
- Other: N/A

Reported statistics and error estimates:

The EC50s at 24 and 48 hours were calculated by Probit analysis using the maximum likelihood estimation method (Finney, DJ, 1971: Probit analysis, Cambridge University Press, Cambridge, UK, 3rd edition).

Validity criteria fulfilled:

yes

Conclusions:

The 48 hr EC50 of the test substance to Daphnia magna was found to be 83.4 mg/L, with a 95% Confidence Interval of 70.5-97.7 mg/L. The no-observed-effect concentration (NOEC) for the test substance with respect to mobility of Daphnia magna was found to be 32 mg/mL after 48 hours of exposure.

Executive summary:

No short-term toxicity to aquatic invertebrates data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to aquatic invertebrates data are 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.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

2008-10-14 to: 2009-03-13

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 to GLP and OECD guideline 202 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 202 (Daphnia sp. Acute Immobilisation 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: 10 mL from each control and treatment at 0 and 48 h 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 and analysed by ICP MS.
- 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: 0.4004 g sodium tungstate dihydrate was dissolved in 2 L aged-blended freshwater. Test concentrations were diluted from this solution.
- Controls: Aged-blended freshwater only.
- Evidence of undissolved material (eg precipitate, surface film, etc): None

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: In-house daphnid culture
- Age at study initiation (mean and range, SD): <24h
- Feeding during test
- Frequency: Not fed during test


ACCLIMATION
- Acclimation period: None necessary, as culture conditions are the same as test conditions
- Type and amount of food: Suspension of Pseudokirchneriella subcapitata, supplemented by artificial diet.
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): No mortality in adults at least 48 h prior to testing

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

144 mg/L CaCO3

Test temperature:

19.3-19.5 °C

pH:

8.3-8.5 SU

Dissolved oxygen:

7.6-7.9 mg/L (85 to 89% saturation)

Salinity:

n/a

Nominal and measured concentrations:

Nominal- 0, 13, 25, 50, 100 and 200 mg/L
Mean Calculated- < MQL, 11.9, 21.5, 41.5, 90.8, and 163 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: Glass 250 mL jars, containing 200 mL test solution, covered with a plastic Petri dish
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ABC well water mixed with well water demineralized by reverse osmosis, then aged in a tank containing aquaticorganisms. Water was then passed through a sediment filter, a UV sterilizer, and aerated 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: 142 mg/L CaCO3
- Conductivity:347 uS
- Culture medium different from test medium: No
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hr light, 8hr dark
- Light intensity: 448 lux as measured with a LI-COR Model LI-189 light meter equipped with a photometric sensor.
- The jars were maintained at 20 ± 2 °C in a temperature-controlled water bath.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility and mortality, 24 hr.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2x
- Range finding study
- Test concentrations: 0, 0.10, 1.0, 10, and 100 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 163 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

based on mean calculated concentrations of sodium tungstate

Basis for effect:

other: immobilization

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 163 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

based on mean calculated concentrations of sodium tungstate

Basis for effect:

other: immobilization

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

90.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

based on mean calculated concentrations of sodium tungstate

Basis for effect:

other: immobilization

Details on results:

Biological Results:
After 48 hours of exposure, immobility was 0, 0, 0, 0, 5 and 15% in the 163 mg /L, the highest level tested. Immobility was significantly increased at only the highest test concentration level. The 48-hour no-observed-effect concentration (NOEC) was determined to be 90.8 mg/L, based on the lack of statistically significant (p=0.05) immobility and sublethal effects at this test substance treatment.

Reported statistics and error estimates:

All statistical analyses were performed with SAS software. 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 by using a one-tailed Dunnett’s test.

Conclusions:

The 48 hour EC50 value was estimated to be >163 mg/L. The 48-hour no-observed-effect concentration (NOEC) was 90.8 mg/L based on the lack of statistically significant (p=0.05) immobility and sublethal effects at this and lower test substance treatments.

Executive summary:

No short-term toxicity to aquatic invertebrates data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to aquatic invertebrates 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.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Well documented, scientifically sound study conducated similar to OECD guideline 202 with minor protocol deviations regarding the test solutions, organisms and the range of temperature (lower than what the guideline specified).

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:

reference to other study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no data

Analytical monitoring:

not specified

Details on sampling:

no data

Vehicle:

no

Details on test solutions:

- Stock solutions were made in distilled water.
- Sodium tungstate was dissolved by boiling in a small amount of dilute HCl.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Wild caught from a natural pond at Gheru Campus of the Industrial Toxicology Research Center, Lucknow, India
- Age at study initiation (mean and range, SD): Not specified
- Feeding during test
- Frequency: Animals were not fed during the bioassay study.


ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): Yes
- Type and amount of food: 100 mg/L suspension of dry fish food (Shalimar Fish Food Company, Bombay) and yeast
- Feeding frequency: Not specified
- Health during acclimation (any mortality observed): Not specified

QUARANTINE (wild caught)
- Duration: Not specified
- Health/mortality: Not specified

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

235-260 mg/L as CaCO3

Test temperature:

11.5-14.5 °C

pH:

7.2-7.8 SU

Dissolved oxygen:

5.2-6.5 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Not specified

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: 200 mL beakers, 100 mL test water. The concentrations were given as milligrams per liter of metal ions.
- No. of organisms per vessel: 10 daphnids
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: filtered aerated tubewell hard water (hardness- 240 mg/liter as CaCO3)
- Metals: 85-96 mg/L (Mg)
- Chlorine: 5-10 mg/L as chloride
- Alkalinity: 390-415 mg/L as CaCO3
- Culture medium different from test medium: No
- Intervals of water quality measurement: 24h


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Mortality (presumed dead when there was complete immobilization): 30 min, 1, 2, 4, 8, 14+2, 24, 33+3, and 48 hr.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: Logarithmic scale (as outlined by APHA et al, 1977), not otherwise specified
- Range finding study
- Test concentrations: Stated as run, no further details
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

89.39 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

As Metal ion

Basis for effect:

mortality

Remarks on result:

other: 95 % CI is 78.04-99.51 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

98.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Remarks:

As Metal ion

Basis for effect:

mortality

Remarks on result:

other: 95 % CI is 68.70-112.60 mg/L

Details on results:

- 48-hr EC50 molarity (M): 4.90 x 10^-4
- log M (pM): 3.31

Reported statistics and error estimates:

EC50 values and 95% confidence limits were calculated by the moving average-angle method of Harris, 1959. APHA et. al, 1977 was used to calculate pH, temperature, dissolved oxygen, hardness, and alkalinity. Negative logarithms of the EC50 values were compared to physicochemical properties of the metal.
Statisitical analysis was performed to find a general correlation, if any, between physiochemical properties and metal ion toxicity. The correlation coefficient (r) between physiochemical properties and EC50 values (pM) was determined by least square procedure (Snedecor and Cochran, 1967).

Conclusions:

The 48 h EC50 for tungsten metal ions to Daphnia magna is 89.39 mg/L, with 95% confidence limits of 78.04-99.51 mg/L.

Executive summary:

No short-term toxicity to aquatic invertebrates data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to aquatic invertebrates 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.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

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 with limited documentation on the preparation of test solutions and test conditions provided and analytical confirmation of test solutions not performed.

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 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

: analytical confirmation of test solutions was not performed

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

N/A

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: N/A
- Source: Daphtoxkit, MicroBio Tests, Inc
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: purchased eggs
- Feeding during test
- Food type: powdered Spirulina algae
- Amount: ad libitum
- Frequency: fed 2 hours prior to test initiation, not fed during test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

No data

Test temperature:

No data

pH:

No data

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

Nominal- Control, 0.09, 0.288, 0.9, 2.88, and 9 g/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: Plastic plates with 24-10 mL test wells.
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): N/A
- Renewal rate of test solution (frequency/flow rate): N/A
- No. of organisms per vessel: 1 per test well, 5 per concentration per plate
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 5 control animals per plate
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: No data


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Standard freshwater similar to OECD guideline.
- Total organic carbon: No data
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine: No data
- Alkalinity: No data
- Ca/mg ratio: No data
- Conductivity: No data
- Culture medium different from test medium: No data
- Intervals of water quality measurement: No data


OTHER TEST CONDITIONS
- Adjustment of pH: No data
- Photoperiod: constant darkness
- Light intensity: N/A


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


TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. 3
- Justification for using less concentrations than requested by guideline: N/A
- Range finding study
- Test concentrations: No data
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

1.7 other: g W/L

Nominal / measured:

nominal

Conc. based on:

other: tungsten concentration

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

0.344 other: g W/L

Nominal / measured:

nominal

Conc. based on:

other: tungsten concentration

Basis for effect:

mobility

Remarks on result:

other: 95% CI = 0.244-0.485 g W/L

Details on results:

- Behavioural abnormalities: No data
- Observations on body length and weight: No data
- Other biological observations: See Table 1 for mortality data
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses: No data
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No data
- Effect concentrations exceeding solubility of substance in test medium: No data

Reported statistics and error estimates:

LC50 values in confidence intervals using the EPA Probit Analysis Program ver 1.5. Other statistical calculations were performed using Statistica 7.0 software.

Table 1. Results of D. magna test with sodium tungstate, alive/dead animals in each group.

Control

0.9 g/L

0.288 g/L

0.9 g/L

2.88 g/L

9.0 g/L

Exposure time

24

48

24

48

24

48

24

48

24

48

24

48

A

5/0

5/0

5/0

5/0

5/0

4/1

4/1

1/4

4/1

0/5

0/5

0/5

B

5/0

5/0

5/0

5/0

5/0

5/0

3/2

2/3

4/1

0/5

0/5

0/5

C

5/0

5/0

4/1

4/1

5/0

5/0

4/1

2/3

3/2

0/5

0/5

0/5

D

5/0

5/0

5/0

5/0

4/1

4/1

5/0

2/3

1/4

0/5

0/5

0/5

% Mortality

0

0

5

5

5

10

15

65

40

100

100

100

 

Validity criteria fulfilled:

not specified

Conclusions:

The 48 hour LC50 of sodium tungstate to D. magna is 0.344 g W/L, with a 95% confidence interval of 0.244-0.485 g W/L.

Executive summary:

No short-term toxicity to aquatic invertebrates data of sufficient quality were available specifically on ammonium metatungstate (target substance). However, short-term toxicity to aquatic invertebrates 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.

Description of key information

The short-term toxicity of ammonium metatungstate to aquatic invertebrates is estimated based on read-across from sodium tungstate.

In a 48-h static test on ammonium paratungstate (APT) with Daphnia magna (water flea), no toxic effects up to the saturation concentration

of APT were observed; therefore, an EC50 could not be derived. However, it can be expressed as greater than the saturation concentration,

or > 4.5 mg W/L. In another acute test with water fleas that tested sodium metatungstate, the 48-h EC50 was found to be 83.4 mg sodium

metatungstate/L (ca. 61.6 mg W/L) based on nominal concentrations (analytical verification of test concentrations was not performed).

Data from three 48-h assays with water fleas are available for sodium tungstate; investigators reported 48-h EC50 (immobilisation) values of

>163 mg sodium tungstate/L (ca. 95.5 mg W/L) (based on mean measured concentrations), 89.4 mg W/L (based on mean measured concentrations) and 344 mg W/L (based on nominal concentrations).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

89.4 mg/L

Additional information

No short-term 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 substance), 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 substances is 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.