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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 April - 09 June 2009
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study but the test substance is highly insoluble in water and analytical verification of test concentrations was difficult.

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)
Remarks:
The Department of Health of the Government of the United Kingdom

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Benzene, 1,1 ‘-(1‚2-ethanediyl)bis-, brominated, [CAS No. 1092834-40-6]; product name: SH-1; reaction product of bromine and 1,2-diphenylethane
- Substance type: white powder
- Physical state: solid
- Analytical purity: >99%
- Composition of test material, percentage of components: Penta bromodiphenylethane 0-2%, Hexa bromodiphenylethane 40-80%, Hepta bromodiphenylethane 1-20%, Octa bromodiphenylethane 1-30%, Nona bromodiphenylethane 0-10%, Deca bromodiphenylethane 0-5%
- Lot/batch No.: 20090105
- Expiration date of the lot/batch: 08 January 2011
- Storage condition of test material: room temperature in the dark

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples were taken from the control and each test group at 0 and 72 hours for quantitative analysis. Duplicate samples were taken at 0 hours and stored at approx. -20°C for further analysis if necessary

Test solutions

Vehicle:
no
Details on test solutions:
The test material solutions were prepared by stirring an excess (50 mg/I) of test material in culture medium using a propeller stirrer at approximately 1500 rpm at a temperature of approximately 21°C tor 24 hours. After the stirring period any undissolved test material was removed by centrifugation at 10000 g for 30 minutes to produce a saturated solution of the test material with a 0-Hour measured test concentration of 0.014 mg/l. This saturated solution was then further diluted as necessary, to provide the remaining test groups.

Following a preliminary range-finding test, Desmodesmus subspicatus was exposed to solutions of the test material at 0-Hour measured concentrations of 0.00035, 0.00082, 0.0021, 0.0037 and 0.014 mg/I (three replicate flasks per concentration) for 72 hours.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: green alga
- Strain: CCAP 276/20
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP), Dunstaffnage Marine Laboratory, Oban, Argyll, Scotland
- Method of cultivation: Master cultures were maintained in the laboratory by the periodic replenishment of culture medium. The master cultures were maintained in the laboratory under constant aeration and constant illumination at 21 ± 1°C

Study design

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

Test conditions

Test temperature:
24 ± 1°C
pH:
pH7.3 — 7.7 at 0 hours
pH 7.6 — 7.9 at 72 hours

The pH deviation in the control cultures was less than 1.5 pH units after 72 hours and therefore was within the limits given in the Test Guidelines
Nominal and measured concentrations:
Based on the resuits of the pre-study media preparation trial anci range-finding test the following nominal test concentrations were assigried to the definitive test: 0.000041, 0.00013, 0.00041, 0.0013 and 0.0041 mg/l.

Chemical analysis of the test preparations at 0 hours showed measured test concentrations to range from 0.00035 to 0.014 mg/l. A decllne in measured test concentrations was observed at 72 hours in the range of less than the limit of quantitation (LOQ) of the analytical method employed which was determined to be 0.00017 mg/l to 0.0026 mg/l.

Details on test conditions:
Based on the resuits of the pre-study media preparation trial anci range-finding test the following nominal test concentrations were assigried to the definitive test: 0.000041, 0.00013, 0.00041, 0.0013 and 0.0041 mg/l.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.006 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
dissolved
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 0.006 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
dissolved
Basis for effect:
growth rate

Any other information on results incl. tables

A decline in measured concentrations was observed, thus the geometric mean measured concentrations was used for calculating EC50 values.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The effect of the test material on the growth of Desmodesmus subspicatus has been investigated and based on the 0-Hour measured test concentrations gave EC50 values of greater than 0.014 mg/L. Correspondingly the No Observed Effect Concentration was 0.014 mg/L.
Based on the geometrie mean measured test concentrations exposure of Desmodesmus subspicatus to the test material gave EC50 values of greater than 0.0060 mg/L. Correspondingly the No Observed Effect Concentration was 0.0060 mg/L. This study showed that there were no toxic effects at saturation.