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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:
2003-2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study following Testing guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
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): Betamethasone
- Substance type: Organic
- Physical state: Off-white crystalline powder
- Lot/batch No.: H032754
- Stability under test conditions: The concentration of Betamethasone was measured at 0 and 48 hours by HPLC method
- Storage condition of test material: The sample was stored at ambient temperature, in the container in which it was received, until required for testing
- Other: The substance was received and assigned the Brixham test substance number 03-0210
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility (under test conditions): 20 mg/l was selected as the maximum test concentration

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 20 mg/l
- Sample storage conditions before analysis: The test solution was prepared at 20°C, centrifuged, and directly used for the experiment

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A 2000 ml volume of the nominal test concentration (20 mg/l) was prepared by the direct addition of betamethasone to diluition water
- Eluate: Recostituted water medium, Elendt's M4 Daphnia medium
- Concentration of vehicle in test medium (stock solution and final test solution): test samples were prepared directly in the Eluate
- Evidence of undissolved material (e.g. precipitate, surface film, etc): some suspended white particles that was removed by centrifugation

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Strain: Clone 5
- Source: Continuous laboratory cultures; parental stock 22 ± 1 days old. Previously obtained by IRCHA (Institute for Applied Chemical Research), France
- Age at study initiation (mean and range, SD): < 24 hours old, obtained from a single culture vessel
- Method of breeding: Daphnia cultures were fed a defined diet of algae Chlorella vulgaris, strain CCAP 211/12 and commercially available fish food
- Feeding during test: daphnia were not fed during the course of the study

Study design

Test type:
static
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
Assessment was made at 24 and 48 h after the commencement of the test

Test conditions

Hardness:
Media was 252.7 mg/l CaCO3; and the conductivity of the water was 626 μS/cm
Test temperature:
Test was carried out at 20 ± 1°C
pH:
pH values of Diluition water batch used in the study (M4 2003-13) was 7.96; during the test ranged from 8.05 to 8.12
Dissolved oxygen:
9.2 mg/l
Nominal and measured concentrations:
Betamethasone concentration 20 mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel: Borosilicate glass beakers of 250 ml
- Type (delete if not applicable): beakers covered with loose fitting glass lids
- Material, size, headspace, fill volume: Each vessel contained 200 ml of test solution providing a depth of approximately 60 mm
- Aeration: Test solution were not aerated during the course of the study
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel: 20 Daphnia/l
- No. of vessels per concentration (replicates): 4 vessels for 24 hours analysis and 4 vessels for 48 hours analysis
- No. of vessels per control (replicates): 4 vessels for 24 hours analysis and 4 vessels for 48 hours analysis
- No. of vessels per vehicle control (replicates):
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Batch number M4 2003-13
- Total organic carbon: 0.77 mg/l
- Particulate matter:
- Metals:
- Pesticides: 0.0286 μg/l
- Chlorine:
- Alkalinity: as CaCO3 40.2 mg/l
- Ca/mg ratio:
- Conductivity: @25°C 626 μS/cm
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 hours light: 8 hours dark, with 20 minute dusk and dawn transition period
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations: 20 mg/l
- Results used to determine the conditions for the definitive study:
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
> 20 mg/L
Nominal / measured:
nominal
Conc. based on:
other: HPLC analysis
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 20 mg/L
Nominal / measured:
nominal
Conc. based on:
other: HPLC analysis
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
20 mg/L
Nominal / measured:
nominal
Conc. based on:
other: HPLC analysis
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: no abnormality observed
- Observations on body length and weight: no abnormality observed
- Other biological observations: no abnormality observed
- Mortality of control: none
- Other adverse effects control: no abnormality observed
- Abnormal responses: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no abnormality observed
- Effect concentrations exceeding solubility of substance in test medium: no abnormality observed

Any other information on results incl. tables

Results of single test Betamethasone concentration

 Time   (hours)  Nominal concentration of betamethasone (mg/l)  Number immobilised per replicate           Total number tested  Total number immobilised  Percentage immobilised
   A  B  C  D      
 24     Diluition water control  0  0  0  0  20  0  0
 20  0  0  0  0  20  0  0
 48     Diluition water control  0  0  0  0  20  0  0
 20  0  0  0  0  20  0  0

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
After 48 hours, there was no effect on mobility at the single test substance concentration of 20 mg/l.
The NOEC based on immobility was 20 mg/l.