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 study according to Guideline OECD 201

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Version / remarks:
2006
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
- Water solubility (under test conditions): not applicable, hydrolysis within hours
- Stability in water: hydrolysis within hours, three detected hydrolysis products (non-GLP pre-test) were detected and quanitfied but due to the low recovery after 72h in algal medlum indicated that a substantial part of further hydrolysis products was not accessible by gas chromatopgraphy

OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: not readily biodegradable

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
DOC measurements due to the fast hydrolysis of both compounds

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Dilution of Stock solution of 100 mg/L
- Due to high volatility of test substance, a 2000 mL volumetric flask was filled with 2000 mL culture medium, 200 mg test substance was added and vessel was directly closed. Preparation was stirred for 5 min with a magnetic stirrer

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Source (laboratory, culture collection): "Sammlung von Algenkulturen" University Göttingen, Germany
- Method of cultivation: culture flasks are stored in an incubator at 25°C +-1 and lighted with 7000-9000 Lux


ACCLIMATION
- Acclimation period: three days before start of the test, two flasks were filled with 100 mL culture medium and 5x10^5 algae from stock culture were added (5x10^3 cells/mL). After three days of incubation the cell concentration was determined by particle counter and was at least 16 x 5000 cells per mL.
- Culturing media and conditions (same as test or not): same as test
- Any deformed or abnormal cells observed: no

Study design

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

Test conditions

Hardness:
not given
Test temperature:
25 + 0.5°C
pH:
Pre-Test (Non-GLP): 100 mg/L showed a pH of 4.8 and 100% growth inhibiton
Main test: stock solution (100 mg/L) was adjusted to pH 8.1 to avoid pH effects of the substance (as seen in the pre-test and Daphnia study)
Begin of the test: 8.02-8.14, end of the test: 8.08 (highest concentration) to 9.57 (control)
Dissolved oxygen:
not reported
Salinity:
0
Nominal and measured concentrations:
nominal: recovery of the DOC during exposure period ranged between 82 and 102% during the 72h exposure period.
The results are given as nominal concentration of the test substance and its hydrolysis products
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 300 mL Erlenmeyer flasks: 150 mL culture medium with test substance
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): no
- Initial cells density: 5 x 10^3 cells/mL
- Control end cells density: algal growth after 72h: factor 108
- No. of vessels per concentration (replicates): 3 + one blank
- No. of vessels per control (replicates): 6 + one blank


GROWTH MEDIUM
- Standard medium used: OECD medium



TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: double desilled water
- Culture medium different from test medium: yes different for stock cultures and test cultures



OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: yes (see field pH)
- Photoperiod:
- Light intensity and quality: 8000 Lux



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: electronic particle counter
- Chlorophyll measurement: no



TEST CONCENTRATIONS
- Spacing factor for test concentrations: no
- Range finding study
- Test concentrations: 0.1-100 mg/L, 100 mg/L with and without pH adjustment
- Results used to determine the conditions for the definitive study: without adjustment of pH 100% inhibition, with adjustment 4.1% at the highest concentration
Reference substance (positive control):
yes
Remarks:
potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
100.5 mg/L
Nominal / measured:
nominal
Conc. based on:
other: DOC
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: DOC
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
25 mg/L
Nominal / measured:
nominal
Conc. based on:
other: DOC
Basis for effect:
growth rate
Details on results:
EC50 value calculated via Toxrat: Growth rate 510.9 mg/L, yield 136.3
NOEC (Yield): 25 mg/L
LOEC (yield and growth rate): at 50 mg/L a significant inhibition of 14.1% (yield) and 3.3 % (growth rate) was observed
Results with reference substance (positive control):
- Results with reference substance valid? yes
- EC50: 0.9 mg/L
Reported statistics and error estimates:
Statistics were calculated via Toxrat

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under conditions tested, the test substance and its hydrolysis products show inhibitory effects in concentrations above 25 mg/L (NOEC). LD50 is higher than 100 mg/L (calculated to be 510.9 mg/L).