Registration Dossier

Ecotoxicological information

Short-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
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:
study well documented, meets generally accepted scientific principles, acceptable for assessment
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 the 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 K2. Due to similar or lower transformation/dissolution results for tungsten blue oxide (the target substance) than sodium tungstate (the source substance), the resulting toxicity potential would also be expected to be similar or lower, so read-across is appropriate. In addition, read-across is justified because the classification and labeling is the same or less severe for the target substance 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 chemical is adequately protective. For more details refer to the attached description of the read across approach.
Justification for type of information:
REPORTING FORMAT FOR THE CATEGORY APPROACH
1. HYPOTHESIS FOR THE ANALOGUE 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: Tungsten blue oxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 1 in CSR
4. DATA MATRIX: See Annex 1 in CSR
Qualifier:
according to
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 degrees 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
Key result
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
other: sodium tungstate concentration
Basis for effect:
mortality
Remarks on result:
other: No mortality in any control or test solution
Key result
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 181 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: sodium tungstate concentration
Basis for effect:
mortality
Remarks on result:
other: No mortality in any control or test solution
Key result
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
200 mg/L
Nominal / measured:
nominal
Conc. based on:
other: sodium tungstate concentration
Basis for effect:
behaviour
Remarks on result:
other: Lack of mortality and sublethal effects
Key result
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
>= 181 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
other: sodium tungstate concentration
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.
Validity criteria fulfilled:
yes
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 fish acute toxicity data of sufficient quality are available for tungsten oxide (target substance). However, fish acute toxicity data are available for sodium tungstate (source substance), which will be used for reading across. Due to lower water solubility and lower toxicity for the target substance compared to the source substance, the resulting read across from the source substance to the target substance is appropriate as a conservative estimate of potential toxicity for this endpoint. In addition, read across is appropriate because the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, lower for the source substance. For more details, refer to the read-across category approach included in the Category section of this IUCLID submission and/or as an Annex in the CSR.

Description of key information

In a flow-through test using zebrafish and testing another soluble tungsten compound with the same classification and PBT profile (sodium tungstate), the LC50 observed was found to be greater than the highest concentration tested (>181 mg sodium tungstate/L or approximately 106 mg W/L).

Key value for chemical safety assessment

LC50 for freshwater fish:
106 mg/L

Additional information

Due to similar or lower transformation/dissolution results for tungsten blue oxide (the target substance) than sodium tungstate (the source substance), the resulting toxicity potential would also be 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 chemical is adequately protective. For more details refer to the attached description of the read-across approach.