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)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test substance: MGDN
- Purity: 99.5 area-% by HPLC-fingerprint 99.9 g/ 100 g by H-NMR spectroscopy

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Samples were diluted in OECD- Medium.

Test solutions

Vehicle:
no
Details on test solutions:
- The test concentrations were prepared by a serial dilution of a stock solution of 111 mg/L.
- The test substance was stirred in OECD-medium for about 15 minutes at 20 ± 2 °C.
- The stock solution was present as clear solution according to visual inspection.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
- Strain: Desmodesmus subspicatus CHODAT SAG 86.81
- Supplier: The test strain of Desmodesmus subspicatus CHODAT SAG 86.81 is obtained at regular intervals from SAG (Collection of algal cultures in Göttingen) and is kept in liquid culture in the Laboratory of Ecotoxicology of the Experimental Toxicology and Ecology, BASF Aktiengesellschaft, Ludwigshafen, Germany.

Study design

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

Test conditions

Test temperature:
21 - 25 °C
Nominal and measured concentrations:
- Test concentrations (nominal): 0, 6.25, 12.5, 25, 50, and 100 mg/L
- The recovery rates of the test substance in the test solutions throughout the exposure period were in a range of + 20% of the nominal concentrations.
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flasks, plugged with gas permeable siliconsponge caps
- Fill volume: 250 mL
- Test volume: 100 mL
- Inoculation density (cells/mL): 0.5X 10E04
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels for analytical control (replicates): 1

GROWTH MEDIUM
- Standard medium used: prepared according to OECD guideline

OTHER TEST CONDITIONS
- Illumination: Artificial light, type universal white (OSRAM L 25), permanent illumination
- Light intensity and quality: About 6000 - 10000 Lux at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED
- Test parameter: In vivo chlorophyll-a-fluorescence (pulsed excitation with light flashes having a wavelength of 435 nm)
- Measurement of fluorescence: After 0, 24, 48 and 72 h
- Cell counting: after 72 h in a counting chamber (Neubauer improved) in replicate No. 2 of the inoculated control
- Measurement of temperature: Continuously during the whole test period in the climate chamber

Results and discussion

Effect concentrationsopen allclose all
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:
NOEC
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:
other: yield
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield
Details on results:
- Since the recovery rates of the test substance in the test solutions were in a range of +20% of the nominal concentrations, the effect concentration can be expressed relative to the nominal concentration.

Applicant's summary and conclusion