2-methylpyridine

Toxicity to aquatic algae and cyanobacteria

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other: GLP status not known, near guideline study, available as unpublished report, minor restrictions in design and reporting but otherwise adequate for assessment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

Test material information

Constituent 1

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 concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

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

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

78.05 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 4

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