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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:
other information
Study period:
2006
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
yes
Remarks:
cell density has been measured by fluorescent reading (not by microscope direct count)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
465-070-0
EC Name:
-
Cas Number:
518048-03-8
Molecular formula:
C16H19FN403
IUPAC Name:
2-(1-amino-1-methylethyl)-N-(4-fluorobenzyl)-5-hydroxy-1-methyl-6-oxo-1,6-dihydropyrimidine-4-carboxamide
Details on test material:
Free Amine Batch Code #200601180120

Test organisms

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

Study design

Test type:
other: continuos illumination and constant shaking
Water media type:
freshwater
Total exposure duration:
72 h
Post exposure observation period:
The algal inoculum was taken from a pre-culture, started 3 days before the beginning of the test in order to ensure that the assay was performed with exponentially growing algal population. The cell density of the inoculum was around 10e6 cells/ml.

Test conditions

Hardness:
Light intensity : 6000 - 10000 lux
Test temperature:
room temperature : 22.1 - 24.8 °C
pH:
At the beginning, the pH values were in the range of 7.71 - 7.93. The range was of 8.25 - 8.84 at the end of the test.
Nominal and measured concentrations:
Five nominal test concentrations were prepared : 1.0 mg/L - 3.2 mg/L - 10.0 mg/L - 31.6 mg/L - 100.0 mg/L
Details on test conditions:
Tests have been conducted under a laminar flow bench to ensure axenicity og the algal cultures. For the test concentrations and for the negative control, 100ml conical glass flasks capped with air permeable stoppers have been used. Three replicates for each concentration and six for control were prepared. 50ml of test solutions were poured into the test flasks and inoculated with algae to obtain a starting cell density of around 10e4 cells/ml. Algal cell density was measured every 24 hours by fluorescent reading with spectrofluorophotometer.

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
NOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Duration:
24 h
Dose descriptor:
LOEC
Effect conc.:
31.6 mg/L
Nominal / measured:
nominal
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
3.2 mg/L
Nominal / measured:
nominal
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
3.2 mg/L
Nominal / measured:
nominal
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
10 mg/L
Nominal / measured:
nominal

Any other information on results incl. tables

The 72 hours EC50 for the test item were as follow :

Endpoint  EC50 (mg/L)  95% LCL (mg/L)  95% UCL (mg/L) 
Growth Rate  51.4  47.3  54.7 
Biomass  9.5  7.3  15.2 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
For the test item Free Amine to Pseudokirchneriella subcapitata, the NOEC and LOEC values after 72 hours are the same for both endpoint, growth rate and biomass growth, respectively 3.2 and 10.0 mg/L.