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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report date:
2003

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Methylurea
EC Number:
209-935-0
EC Name:
Methylurea
Cas Number:
598-50-5
Molecular formula:
C2H6N2O
IUPAC Name:
methylurea
Details on test material:
- Name of test material (as cited in study report): Methylharnstoff
- Lot/batch No.: 001V36AX10
- Analytical purity: 98 %

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution(125.5 mg/l) was prepared by stirring the test substance in demineralized water for about 10 min at approximately 20 ± 2°C .

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: CHODAT SAG 86 .81
- Source (laboratory, culture collection):

Study design

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

Test conditions

Test temperature:
23 ± 2 °C
pH:
7.9 - 8.5
Nominal and measured concentrations:
Nominal test substance concentrations:
12.5, 25, 50, 100 mg/l

Analytical test substance concentrations:
12.0 (12.5 nominal), 96.1 (100 nominal) mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flasks (250 ml)
- Fill volume: 100 ml
- Initial cells density: 10000
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Test medium according to The test substance was stirred in demineralized water for about 10 min at approximately 20 t 2°C .
The stock solution appears clear and colourless .
The nominal concentration of the stock solution was 125,5 mg/I .EEC Directive 92/69/EEC, Annex V, Part C.3 .

OTHER TEST CONDITIONS
- Photoperiod: permanent illumination
- Light intensity and quality: artificial light, type universal white (OSRAM L 25), about 60 - 120 µE/(m²s) at a wave length of 400 - 700 nm


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chamber (Neubauer improved)
- Chlorophyll measurement: vivo chlorophyll-a-fluorescence (pulsed excitation with light flashes having a wavelength of 435 nm

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion