Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Specific details on test material used for the study:
Identification: Tungstosilicic-acid
Physical state/Appearance: White Crystalline Solid
Batch: MKBR8664V
Purity: 65.0% w/w
Expiry Date: 26 August 2016
Storage Conditions: Room temperature in the dark over silica gel

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Sampling for analysis at 0 and 48 hours.

Test solutions

Vehicle:
no
Details on test solutions:
A nominal amount of test item (2000 mg) was dissolved in test water and the volume adjusted to 2 liters to give the 1000 mg/L test concentration from which a series of dilutions was made to give further test concentrations of 56, 100, 180, 320 and 560 mg/L. Due to the acidic nature of the test item, the pH of the 1000 mg/L test concentration was adjusted using 1 Molar NaOH to 7.7 prior to preparation of the test series.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Source: in-house laboratory cultures.
- Age of test items k (mean and range, SD): <24 hours
- Feeding of stock: mixture of algal suspension (Desmodesmus subspicatus) and Tetramin flake food suspension.
- Frequency: daily.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
250 mg/L as CaCO3
Test temperature:
21 to 22 C
pH:
7.8 +/-22
Dissolved oxygen:
8.1 - 8.4mg O2/L
Nominal and measured concentrations:
Nominal: of 56, 100, 180, 320, 560, 1000 mg/L.
Measurements at time 0: 46, 87, 159, 299, 511, 948mg/L
Measurements at time 48hrs: 39, 68, 118, 210, 378, 966mg/L
Geometric means: 42, 77, 137, 251, 439, 957mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:150ml glass jars
- Type (delete if not applicable): covered
- Material, size, headspace, fill volume: 100ml fill
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- 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: Elendt M7 Medium - reconstitued water.

OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod: 16/8 (light/dark)
- Light intensity: 1200Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mobility

VEHICLE CONTROL PERFORMED: not applicable

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.0, 10, 100 and 1000 mg/L -with and without pH adjustment.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
120 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC0
Effect conc.:
77 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Results with reference substance (positive control):
EC50(48hr) 0.54mg/L. The results from the positive control with potassium dichromate were within the normal range for this reference item.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

In a guideline study, daphnia magna were exposed to tungstosilicic acid for a period of 48hrs. An EC50 value of 120mg/L was established.