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
Study period:
from 1995-05-03 to 1995-11-15
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline-conform study performed under GLP without deviations

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): β-Carotin
- Physical state: brown solid
- Analytical purity: 99.8%
- Purity test date: 040860
- Lot/batch No.: 405108
- Expiration date of the lot/batch: 27/10/95
- Storage condition of test material: room temperature, in darkness

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: 10, 18, 32, 58 and 100 mg/L (nominal)
- Sampling method: Composite samples (about 150 mL per concentration and control) of each test concentration were drawn by mixing identical volumes of the test solutions taken from the test vessels. Samples of test solutions were taken immediately before exposure and after 72 hours exposure and stock solution (almost equal to highest test concentration) was taken 24 hours before exposure.
- Sample storage conditions before analysis: All samples were kept at -18 °C to -22 °C until analysis.



Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 200.9 mg test substance and 208 mg of dimethylformamid/Tween 80 (96/4 % w/w) were mixed. This blend was mixed and made up to 200 mL with reconstituted water. Calculated amounts of this stock solution and vehicle to achieve identical vehicle concentrations at all test concentrations were given into the water and were homogeneously distributed. The test solutions were equilibrated for 24 hours under test conditions.
- Differential loading: No
- Controls: vehicle control, water control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): dimethylformamid/Tween 80 (96/4 % w/w)
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): 96 mg dimethylformamid/L and 4 mg Tween 80/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Some deposit of the test substance was observed at test concentrations 10-100 mg/L at the start and at test concentrations 58 and 100 mg/L at the end of exposure. Parts of the test substance were swimming on the surface of the test water at test concentrations 58 and 100 mg/L at the start and at test concentrations 10-100 mg/L at the end of exposure.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: green algae
- Strain: 61.81 SAG / ATCC 22662
- Source (laboratory, culture collection): collection of algae cultures, Pflanzenphysiologisches Institut, Göttingen, Germany
- Method of cultivation: according to guideline

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): same

Study design

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

Test conditions

Hardness:
35 mg CaO/L
Test temperature:
22 ± 1 °C
pH:
Test start: 8.1
Test end: 8.1 - 8.7
Nominal and measured concentrations:
Nominal: 10, 18, 32, 58, 100 mg/L
Measured, start of test: 16.6, 37.1, 60.0, 104, 163 mg/L
Measured, end of test: 5.0, 9.1, 13.1, 29.7, 47.8 mg/L
Calculated actual mean concentrations: 10.8, 23.1, 36.6, 66.9, 105.4 mg
Details on test conditions:
TEST SYSTEM
- Test vessel: flasks
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass 100 mL Erlenmeyer flasks (total volume 125 mL)
- Renewal rate of test solution (frequency/flow rate):
- Initial cells density: 10600 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Composition according to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: cold white fluorescent light at 120 µE/m²sec (approx. 8000 lux)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: "TOA" cell counter

TEST CONCENTRATIONS
- Range finding study: no
- Test concentrations: Nominal test concentrations of 10, 18,32, 58 and 100 mg test substance per litre. The measured test substance concentrations were 16.6, 37.1, 60.0, 104, 163 and 5.0, 9.1, 13.1, 29.7 and 47.8 mg of test substance per litre at the start and end of exposure, respectively.

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
231 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 180 - 371 mg/L
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
81 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 63 - 112 mg/L
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
< 10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
< 10 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
- Adherence to test vessels: Some deposit of the test substance was observed at test concentrations 10-100 mg/L at the start and at test concentrations 58 and 100 mg/L at the end of exposure.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Parts of the test substance were
swimming on the surface of the test water at test concentrations 58 and 100 mg/L at the start and at test concentrations 10-100 mg/L at the end of exposure.

Any other information on results incl. tables

The calculated actual mean concentrations 10.8, 23.1, 36.6, 66.9 and 105.4 mg test substance/L were practically within 100 · 20 % of the nominal concentrations, therefore EC50 values were based on nominal concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The ErC50 (0-72 h) was nominal 231 mg/L and EbC50 (0-72 h) was nominal 81 mg/L.
Executive summary:

The test was conducted to determine the concentration at which the growth of green algae (Selenastrum capricornutum) is reduced by 50% in relation to control. The test was conducted according to OECD TG 201.

After a preculture period of 3 days, Selenastrum capricornutum (initial cell density 10600 cells/mL) was exposed to nominal test concentrations of 10, 18,32, 58 and 100 mg/L. The measured test substance concentrations were 16.6, 37.1, 60.0, 104, 163 and 5.0, 9.1, 13.1, 29.7, 47.8 mg/L at the start and the end of exposure, respectively. The calculated actual mean concentrations 10.8, 23.1, 36.6, 66.9 and 105.4 mg/L were practically within 100 · 20 % of the nominal concentrations, therefore following values were based on nominal concentrations. The ErC50 (0-72 h) was nominal 231 mg/L and EbC50 (0-72 h) was nominal 81 mg/L. The NOEC was < 10 mg/L.