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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:
27-nov-2008 to 29-nov-2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
2-[2-(carboxymethyl)phenoxy]-3,4-dimethylbenzoic acid
EC Number:
601-485-7
Cas Number:
117570-93-1
Molecular formula:
C17 H16 O5
IUPAC Name:
2-[2-(carboxymethyl)phenoxy]-3,4-dimethylbenzoic acid
Details on test material:
- Name of test material (as cited in study report): ASA404 C7
- Substance type: Off white powder
- Physical state: Solid
- Analytical purity: 99.9%
- Lot/batch No.: 072301
- Expiration date of the lot/batch: 18 March 2009
- 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: Volume, 2 ml from the approximate centre of the test vessels at t=0 and t=48 h
- Sample storage conditions before analysis: Samples were stored in a freezer until analysis

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with a loading rate of 100 mg/l applying a 10-minute treatment period with ultrasonic waves followed by 74 hours of magnetic stirring to accelerate the dissolving of the test substance in the test medium. Obtained solutions contained undissolved material dispersed through and floating on the surface. The dispersion was consequently filtered through a 0.45 µm membrane filter (Whatman, RC55) to remove the non-dissolved material. The lower test concentrations were prepared by subsequent dilutions of the flitrate in test medium. The final test solutions were all clear and colourless.



Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: In-house laboratory culture
- Age at study initiation (mean and range, SD): <24 hours
- Method of breeding: Start of each batch, 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


Study design

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

Test conditions

Hardness:
180 mg/l expressed as CaCO3
Test temperature:
19.6 - 20.8 °C
pH:
At t=0: 6.3 - 7.9
At t=48: 7.1 - 8.0
Dissolved oxygen:
At t=0: 8.9 - 9.4
At t=48: 8.9
Nominal and measured concentrations:
Nominal concentrations: 0.1, 1, 10 and 100 mg/l
Measured concentrations:
At t=0: 96.5% of nominal
At t=48: 98% of initial
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 ml, all-glass
- Type (delete if not applicable): open - Material, size, headspace, fill volume: glass, ~80ml, normal headspace
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 for the highest test concentration, 2 in the lower test concentrations
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source preparation of dilution water: Adjusted ISO medium
- Culture medium different from test medium: yes for culturing M7 medium is used

OTHER TEST CONDITIONS
- Adjustment of pH: 7.7 ± 0.3
- Photoperiod: 16 hours photoperiod daily

EFFECT PARAMETERS: EC50 daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
Reference substance (positive control):
yes
Remarks:
potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: no
- Mortality of control: no
- Other adverse effects control: not observed
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- EC50/LC50:
The 24h-EC50 was 0.57 mg/l with a 95% confidence interval between 0.52 and 0.66 mg/l.

The 48h-EC50 was 0.35 mg/l with a 95% confidence interval between 0.31 and 0.40 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
ASA404 C7 did not induce acute immobilisation of Daphnia magna at or below 10 mg/l after 48 hours of exposure (NOEC). A total of 40% immobile daphnia were observed at the highest test concentration of 100 mg/l.

Therefore, it is concluded that this study is valid and the 48h-EC50 exceeded 100 mg/l based on analytically confirmed nominal concentrations.