Betamethasone

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

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Betamethasone

EC Number:

206-825-4

EC Name:

Betamethasone

Cas Number:

378-44-9

Molecular formula:

C22H29FO5

IUPAC Name:

9-fluoro-11,17,21-trihydroxy-16-methylpregna-1,4-diene-3,20-dione

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 concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 20 mg/L

Nominal / measured:

nominal

Conc. based on:

other: HPLC analysis

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 20 mg/L

Nominal / measured:

nominal

Conc. based on:

other: HPLC analysis

Basis for effect:

mobility

Effect concentrations 3

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.