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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:
02/03/2011 - 04/03/2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The test was performed according to the OECD guidelines and following GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

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:
other: "Alga growth inhibition test, Daphnia sp. acute immobilisation test, and fish acute toxicity test" Yakushokuhatsu No. 1121002, Heisei 15.11.13 Seikyoku No. 2, Kanpokihatsu No. 031121002, November 21, 2003; the latest revision November 20, 2006
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): SX-1
- Substance type: yellow-white powder
- Physical state: solid
- Analytical purity: 99.8%
- Lot/batch No.: 008809
- Stability under test conditions: stable
- Storage condition of test material: room temperature, shaded

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0.22 mg/L
- Sampling method: (at the beginning of exposure) 0.75 ml of test solution from the middle layer of one vessels (diluted suitably with purified water if it was predicted that the concentrations will exceed the ones of the calibration curve). Next, 0.75 ml of solution and 0.75 ml of acetonitrile were mixed and the resulting solution was analysed by LC/MS.
(at the end exposure): 0.75 ml of test solution from the middle layer of one vessels (diluted suitably with purified water if it was predicted that the concentrations will exceed the ones of the calibration curve). Next, 0.75 ml of solution and 0.75 ml of acetonitrile were mixed and the resulting solution was analysed by LC/MS.
- Sample storage conditions before analysis: not indicated

Test solutions

Vehicle:
yes
Details on test solutions:
The test solutions were prepared as follows:

(1) Preparation of stock solution I: 44 mg of test substance were dissolved in 20 ml N,N-dimethylformamide and mixed by inversion. The resulting concentration was of 2200 mg/L. The test solution was fresh prepared, just before the exposure.

(2) Preparation of stock solution II: 100 ul of stock solution I were mixed with 1000 ml of dilution water. The stock solution was added to the medium while stirring, and then the resulting solution was sonicated for 30 min. The resulting concentration of stock solution II was 0.22 mg/L.

(3) Preparation of the solvent stock solution: 50 ul dimethylformamide was mixed with the 500 ml of dilution water. The stock solution was mixed by inversion.

The stock solution (2) and the solvent stock solution (3) were used as such for the final test. In both cases, the final solvent concentration was 100 ul/L. Dilution water only was used in the control group.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia
- Strain: Magna
- Source: National Institute for Environmental Studies, Japan
- Age at study initiation (mean and range, SD): less than 24 h old (females)
- Method of breeding: the parental daphnids were cultured in dechlorinated water for 48 h or more after rearing in Elendt M4 medium. The biomass loading rate was 1 daphnid/80 ml.
- Feeding during test: no


ACCLIMATION
- Acclimation period: Juveniles, less than 24 h old females were used for the test. At the start of exposure, it was confirmed that the parental daphnids fulfilled the following conditions: week age (2-4 weeks, cultured from February 2 to March 2, 2011), mortality during this period was 20% or less and no abnormalitioes were observed.
- Acclimation conditions (same as test or not): yes
- Type and amount of food: 6 mg organic carbon/2 L (source: Chlorella vulgaris)
- Feeding frequency: daily


Study design

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

Test conditions

Hardness:
53 mg CaCO3/L
Test temperature:
20.0 - 20.2 deg C
pH:
7.4
Dissolved oxygen:
8.1 -.8.7 mg/L
Nominal and measured concentrations:
nominal: 0.22 mg/L
measured (time-weighted mean) 0.219 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: beaker
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 100 ml/vessel
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates):4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated water produced by the treating Yokohama city tap water, produced with an activaed charcoal filter and sodium thiosulfate
- Total organic carbon: N.D. (N.D. = not detected)
- Particulate matter: N.D.
- Metals: N.D.
- Pesticides: N.D.
- Chlorine: N.D.
- Alkalinity: 39 mg CaCO3/L at pH 4.8
- Ca/mg ratio: 15/3.9
- Conductivity: 14 mS/m
- Culture medium different from test medium: no
- Intervals of water quality measurement: every 6 months

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/8 h dark
- Light intensity: 800 lux or less

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : median effect concentration at 24 h and 48 h. effect parameters: mobility/mortality/behaviour & appearance

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Only 0.22 mg/L was used
- Justification for using less concentrations than requested by guideline: the results of range finding study
- Range finding study
- Test concentrations: solvent control, 0.022, and 0.22 mg/L
- Results used to determine the conditions for the definitive study: After 48 h exposure, no immobility of daphnids was noticed in any of the concentrations tested.
Reference substance (positive control):
yes
Remarks:
poatssium dichromate

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 0.22 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: no
- Observations on body length and weight: no
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no effects observed
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Mortality: yes
- EC50/LC50: 0.80 mg/L (95 % C.L. 0.67-1.00 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of the test, SX-1 did not induce immobility in Daphnia up to its solubility limit (EC50 > 0.22 mg/L). Based on the current results and owing to the low water solubility (< 0.1 mg/L), SX-1 should not be classified as Acute 1.