Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
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:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
yes
Remarks:
the test method was modified to quantify the a!gicidal effect of the test item, but also the growth inhibition effect caused by reduced light intensities in the colored test media .
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Basic Yellow 8511
- Physical state: solid powder
- Analytical purity: 96.1 %
- Lot/batch No.: ZD 00969/086

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:
The test medium of the highest test item concentration of nominal 100 mg/L was prepared
dissolving 70 mg of the test item completely in 700 ml test water by stirring for 15 minutes .
Adequate volumes of this intensively mixed test medium were added to test water to prepare
the test media of the lower nominal test concentration

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: green algae
- Strain: Scenedesmus subspicatus CHODAT, Strain No. 86.81 SAG
- Source: The test organism was supplied by the "Sammlung von Algenkulturen, Pflanzenphysiologisches Institut
der Universität Göttingen", D-37073 Göttingen . The algae had been grown in the RCC laboratories under standardized conditions according to the test guidelines .

Study design

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

Test conditions

Hardness:
0.24 mmol/L CaCO3
Test temperature:
23 - 24 °C
pH:
7.6 - 9.6
Nominal and measured concentrations:
nominal test concentrations: 32, 10, 3.2 and 1.0 mg/L, a control was tested in parallel.
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmayer flasks
- Type: closed
- fill volume: 15 ml algal suspension
- Initial cells density: 10 000 algal cells per ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes


OTHER TEST CONDITIONS
- Sterile test conditions: yes/no
- Adjustment of pH: no
- Photoperiod: continuously illuminated
- Light intensity and quality: light intensity of about 8200 Lux, range 7400 -9200 Lux. This illumination was achieved by fluorescent tubes (Philips TLD 36W/840), installed above the algal flasks.


EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: Small volumes of the test media and the control (1 .0-2 .0 ml) were taken out of all test flasks
after 24, 48 and 72 hours of exposure and were not replaced. The algae cell densities in the
samples were determined by counting with an electronic particle counter (Coulter Counter®,
Model ZM), at least two measurements per sample .


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
97 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
3.2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
11 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
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
16 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
3.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
71 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass

Any other information on results incl. tables

In Experimental part B the algal growth inhibition caused by the pure light effect (the

reduced light intensities in the colored test media) was quantified.

Results of part B were:

EC10 = 32 mg/L and EC50 = 242 mg/L for growth rate.

EC10 = 12 mg/L and EC%= = 60 mg/L for biomass

The effects seen in this study may be related to the test substance

and/or its hydrolysis products, which are formed within a very short time period

( 6 hours) in an environmental relevant pH-range .

Applicant's summary and conclusion