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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP status not known, near guideline study, available as unpublished report, minor restrictions in design and reporting but otherwise adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report date:
1990

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Desmodesmus subspicatus was exposed to the test substance for 72 hours. The algae density was determined with a fluorimeter.
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylpyridine
EC Number:
203-643-7
EC Name:
2-methylpyridine
Cas Number:
109-06-8
Molecular formula:
C6H7N
IUPAC Name:
2-methylpyridine
Details on test material:
- Name of test material (as cited in study report): 2-Methylpyridin
- Intrinsic colour: yellow

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
not specified
Details on test solutions:
Sample preparation: samples (8 mL) were stirred for 5 hours at 23 °C.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Strain: SAG 86-81

CULTURE CONDITIONS
- Medium: OECD - medium
- Temperature: 23 °C
- Glasswork: 250 mL Erlenmeyer, filled with 100 mL culture medium
- Growth period: 72 h
- Initial cell density: set at 1.0E+04 cells/mL

Study design

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

Test conditions

Test temperature:
Ambient
Nominal and measured concentrations:
- Nominal concentrations: 0 (control), 3.9, 7.8, 15.625, 31.25, 62.5, 125, 250, and 500 mg/L
- Mesaured concentrations: no data
Details on test conditions:
TEST SYSTEM
- Test vessel: flask
- Control end cells density: Initial cell density of the negative control was 49.6 relative units and after 72 hours 2141 relative units measured with fluorescence
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: fluorimeter, measurements after 0, 24, 48 and 72 hours.
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 500 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
44.24 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
78.05 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
32.11 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
See "Any other information on results incl. tables".

Any other information on results incl. tables

Inhibition of biomass and growth rate

Conc.

(mg/L)

% Inhibition of biomass

% Inhibition of growth rate

0 (control)

-

-

3.90

0.78

0.13

7.80

5.34

0.54

15.63

7.70

2.05

31.25

8.75

1.97

62.5

40.80

17.99

125

69.50

41.86

250

77.23

48.63

500

77.66

48.90

Applicant's summary and conclusion