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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:
2007
Reliability:
1 (reliable without restriction)
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
due to the low water solubilty a dispersion of the test item with a loading rate of 100 mg/l was filtered. The undiluted filtrate and the dilution of 1:2.2, 1:4.6, 1: 10 and 1: 22 were used as test media

Test solutions

Vehicle:
no
Details on test solutions:
Due to the low water solubility of the test item, a dispension of the test item with the loading rate of 100 mg/L was prepared by dispersing 500.2 mg of the test item in 5000 mL of test water using ultrasonic treatment for 15 minutes and intense stirring. No auxiliary solvent or emulsifier was used. the dispersion was stirred by a megnatic stirrer at room temperature in the dark over 3 hours. Then, the dispersion was filterd.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: formerly Selenastrum capricornutum
- Strain: 61.81 SAG

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
no

Test conditions

Hardness:
0.24 mmol/L = 24 mg/L as CaCO3
Test temperature:
23 - 24°C
pH:
8.2 - 8.4 at the start to 9.1 - 9.2 at the end of the test
Dissolved oxygen:
n.a.
Salinity:
n.a.
Nominal and measured concentrations:
nominal: 100 mg/l
measured concentration after filtration: 8.8 µg/l
mean measured: 7.9 µg/l
Details on test conditions:
test started by inoculation of 10 000 algal cell per ml of test medium;
three replicates per test concn. and six replicates for the control;
the algal cell densities were determined with an electronic particle counter;
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 7.9 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Results with reference substance (positive control):
- Results with reference substance valid? y

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
No effects on Green Algae until the limit of water solubility at 7.9 µg/l.