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
Study period:
November 19 - 21, 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Corsair Clear #12
- Substance type: Soft waxy beige solid
- Physical state: Solid
- Stability under test conditions: stable
- Storage condition of test material: At room temperature in the dark

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: all test concentrations and control
- Sampling method: 40 ml from the approximate centre of the test vessels
- Sample storage conditions before analysis: refrigerator

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with loading rates of 1.0, 10 and 100 mg/l. The aqueous mixtures were treated with ultrasonic waves for 5 minutes, followed by a 24-hour magnetic stirring period and a 3 hour stabilisation period. The resulting mixture at 100 mg/L was slightly hazy with a floating layer, while the mixtures at the lower loading rates were clear and colourless. In all solutions, undissolved test substance was still present on the cover glasses used for the addition of the test substance to the ISO-medium. Therefore, all three mixtures were passed over glass wool, after which they were clear and colourless.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Source: In-house laboratory culture with a known history.
- Age at study initiation (mean and range, SD): < 24 hours
- Method of breeding: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
- Feeding during test: no feeding

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
No post exposure observations.

Test conditions

Hardness:
180 mg/l expressed as CaCO3
Test temperature:
19.0 - 19.9 °C
pH:
7.8 - 7.9
Dissolved oxygen:
9.1 - 9.6 mg/l
Nominal and measured concentrations:
Loading rate 0 mg/l t=0h : TOC = 0.1477 mg/l
Loading rate 0 mg/l t=48h : TOC = 0.2173 mg/l
Loading rate 100 mg/l t=0h : TOC = 1.336 mg/l
Loading rate 100 mg/l t=48h: TOC = 0.3103 mg/l
The TOC contents in treated samples were comparable or only slightly higher than those in control samples, indicating that the actual test substance concentration was very low. This is not unexpected considering the presence of undissolved test substance and a floating layer in the solution, which were removed by passing the solution over glass wool.
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 ml, all-glass
- Aeration: No aeration of the test solutions
- No. of organisms per vessel: 5 per vessel containing 80 ml of test solution
- No. of vessels per concentration (replicates): 4 for the highest concentration; 2 each for the lower concentrations
- No. of vessels per control (replicates): 4 each for the control

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium
- Total organic carbon: 0.15 mg/l
- Culture medium different from test medium: yes, for culturing M7 medium is used

OTHER TEST CONDITIONS
- Adjustment of pH: 7.7
- Photoperiod: 16 hours daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Range finding study: study was a combined limit/range finding test
- Test concentrations: 0, 1, 10 and 100 mg/l
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
loading rate
Basis for effect:
mobility
Details on results:
No immobility was observed in the control or any of the test concentrations.
Results with reference substance (positive control):
- Results with reference substance valid: Yes
- Immobility after 48h: 5% at 0.10 mg/l; 0% at 0.18 mg/l; 15% at 0.32 mg/l; 75% at 0.56 mg/l; 100% at 1.0 and 1.8 mg/l
- EC50/LC50: 48h-EC50 was 0.45 mg/l with a 95% confidence interval between 0.35 and 0.56 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the conditions described in this study, Corsair Clear #12 did not induce acute immobilisation of Daphnia magna at a loading rate of 100 mg/l after 48 hours of exposure (NOEC). Due to the very low solubility of Corsair Clear #12 in water, concentration levels that might be toxic for daphnids could not be reached. Hence the 48h-EC50 was above a loading rate of 100 mg/l.