Registration Dossier

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
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Concentrations: 200 and 100 mg/L (nominal)
Sampling method: Filtration of test medium samples (10 mL) taken at the start of the tests, 24, and 72 hours of exposure

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Study design

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

Test conditions

Hardness:
24 mg CaCO3/L
Test temperature:
22.5 - 24 °C
pH:
8.0 - 8.4
Nominal and measured concentrations:
Water accomodated fractions were prepared with a loading rate of 100 and 200 mg/L. Measured concentrations were at most 2 mg/L. The test substance is rapidly degraded by photolysis.
Details on test conditions:
TEST CONCENTRATIONS
- Rough filtrates (ca. 5 µm) of supersaturated solutions of 100 and 200 mg/L stirred for ca. 4 days.
- Justification for using less concentrations than requested by guideline: The substance is insoluble in water (< 0.006 g/L at 20 °C).
- Range finding study: A measured concentration of 4.7 mg/L was found in the sample taken from the filtrate. Instead of testing dilutions containing 0.1 to 100 % of the filtrate, test solutions contained 0.05 to 50 % of the filtrate yielding a test substance concentration range from 0.002 to 2.35 mg/L. No inhibition of algal growth was observed at any of the test concentrations.
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 2 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: No acute toxic effects within the range of solubility
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 2 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: No acute toxic effects within the range of solubility
Details on results:
Exponential growth in the control (for algal test): yes
Observation of abnormalities (for algal test): None
Results with reference substance (positive control):
Results with reference substance valid? Yes
EC50: 0.98 mg/L (growth inhibition); 1.1 mg/L (growth rate reduction)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
No acute toxic effects within the range of solubility. The test substance is with high probability acutely not toxic to aquatic algae.