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:
2006
Report Date:
2006

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

Test solutions

Vehicle:
no
Details on test solutions:
Test substance was mixed into the algal medium as homogeneously as possible by ultrasonic treatment for 15 minutes and stirring for 4 hours at room temperature in the dark to dissolve a maximum concentration of the test substance in the dispersion. The supersaturated stock dispersion was filtered through a 0,45 micrometer membrane filter. The undiluted filtrates were used as test stock solutions.

Test organisms

Test organisms (species):
other: Scenedesmus obliquus

Study design

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

Test conditions

Test temperature:
23°C
pH:
7.9 - 8.73
Nominal and measured concentrations:
measured concentrations in mg/l - final test:
test start test end mean value
1.71 0.82 1.27
3.08 0.95 2.02
5.26 1.47 3.37
9.06 2.04 5.55
15.6 3.28 9.44
Details on test conditions:
Cultures with more than 1.0 x 10000 cells/ml
light intensity 8000 Lux
light-dark cacle of 10 h : 14 h for 72 h
cell counts after 24, 48 and 72 hours
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 1.83 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
dissolved
Basis for effect:
biomass
Details on results:
After a culture period of 72 hours, the percentage inhibition of the test substance at each concentration to the algae cell growth was calculated as 41.3%, 53.2%, 62.5%, 72.5%, 82.5%.
Results with reference substance (positive control):
72h-EbC50 = 0,37 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test substance is toxic to aquatic organisms and may cause long term adverse effects in the aquatic environment.
The test substance is toxic to aquatic life with long lasting effetcs.