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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:
21 December 2007 - 7 February 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD 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
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: Daphnia sp., Acute Immobilization Test stipulated in the "Testing Methods for New Chemical Substances" (November 21, 2003; No. 1121002, MHLW; November 13, 2003, No. 2, METI; No. 031121002, MOE, Japan)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Details on test material:
- Name of test material (as cited in study report): S-500
- Substance type: yellow powder
- Physical state: solid
- Lot/batch No.: MF1456-2345
- Stability under test conditions: stable (confirmed by IR)
- Storage condition of test material: dark storage place at room temperature

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: control and 100 mg/l (nominal)
- Sampling method: Equal volume for analysis was taken out from the middle layer of the test solution for each vessel and mixed. This was done at the start of exposure and the end of exposure.
- Sample storage conditions before analysis: not applicable

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: mixing and stirring by magnetic stirrer for 48 h, followed by suction filtration with 0.4 µm glass fibre filter and 1 h stirring.
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): not applicable

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Strain: Clone A
- Source: In-house culture, but daphnids originally came from the University of Sheffield, UK.
- Age at study initiation (mean and range, SD): <24 hours
- Method of breeding: not indicated
- Feeding during test: no

ACCLIMATION
- Acclimation period: not applicable
- Acclimation conditions (same as test or not): parents: yes
- Type and amount of food: parents: Chlorella vulgaris (0.1-0.2 mg C/day per Daphnia)
- Feeding frequency: parents: once daily
- Health during acclimation (any mortality observed): parents: no mortality

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
37 mg CaCO3/l
Test temperature:
20°C
pH:
7.9
Dissolved oxygen:
8.7-8.8 mg/l
Salinity:
Not applicable.
Nominal and measured concentrations:
Nominal 100 mg/l:
peak 1 not detected (< 0.000071 mg/l),
peak 2 not detected (<0.00031 mg/l),
peak 3 not detected at the start of the test (<0.0024 mg/l), but 0.0028 mg/l at end of test
peak 4 not detected (<0.0045 mg/l)
Test item (i.e. sum of 4 peaks) not detected (<0.0073 mg/l).
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed with lid
- Material, size, headspace, fill volume: 100 ml glass beaker, fill volume 100 ml
- 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: dechlorinated tap water
- Total organic carbon: <0.1 mg/l
- Particulate matter: <1 mg/l
- Pesticides: <0.0001 mg/l each
- Chlorine: <0.02 mg/l
- Alkalinity: 29 mg/l
- Ca/mg ratio: 10.3 / 2.8
- Conductivity: 15.5 mS/m
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h dark
- Light intensity: artificial light of white fluorescent lamp

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 and EL50
Reference substance (positive control):
yes
Remarks:
K2Cr2O7

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: effect concentration > solubility of test item in dilution water
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: no abnormalities
- Mortality of control: no immobility
- Effect concentrations exceeding solubility of substance in test medium: no effects above the solubility of the test substance.
Results with reference substance (positive control):
- Results with reference substance valid? Yes
- EC50/LC50: 48-h EC50 0.28 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The study was conducted as a limit test in order to confirm the effect of the test item on the test organisms at around the solubility of the test item in dilution water. As a result, the concentration of the test item in test solutions during the exposure was below the determination limit (<0.0073 mg/L), indicating that the concentrations of the dissolved test item in dilution water was not clarified. However, no adverse effect was found in the definitive study. Therefore, it was decided that the test item had no adverse acute effect on the test organisms at around the solubility in dilution water. The environmental conditions were within the suitable range, therefore, it was concluded that the study complied with the applied test guidelines.