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:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Qualifier:
according to guideline
Guideline:
EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
Avena Sativa leaf/stem extract
EC Number:
948-064-7
IUPAC Name:
Avena Sativa leaf/stem extract

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Source: The algae were supplied by the SAG: Collection of Algal Cultures, Inst. Plant Physiology, and University of Göttingen, GERMANY. Cultured under standardised conditions (see OECD 201) in the Ecotoxicological Laboratory of Citoxlab Hungary Ltd.
Justification of species: The species of Pseudokirchneriella subcapitata used, being a fast-growing species, is convenient for culturing and testing and is a recommended species by relevant guidelines.
Breeding conditions: Stock cultures are small algal colonies that are inoculated onto agar regularly. These are transferred to fresh agar medium at least once every two months and are maintained under standardised conditions according to the test guidelines.
The pre-culture is intended to give a quantity of algae suitable for the inoculation of test cultures. The pre-culture was prepared with the OECD algal growth medium, incubated under the same conditions as the test and used when still growing exponentially, after an incubation period of three days. When the algal cultures contain deformed or abnormal cells, they were discarded.

Study design

Total exposure duration:
72 h
Remarks on exposure duration:
The exposure time was 72 hours. The test was started (0 hours) by inoculation of a biomass of approximately 104 algal cells per mL test medium.

Test conditions

Test temperature:
Culture temperature was checked at the beginning of the experiment and each day thereafter in a flask filled with water, in the climatic chamber. In addition, water temperature was continuously measured (with a min/max thermometer) within the climate chamber. The temperature was in the range of 22.4 – 22.7 °C measured in the flask and between 22.1 and 23.1 °C measured within the climate chamber.
pH:
The pH was checked at the beginning and at the end of the test in each test vessels. The pH of the control medium was not increased by more than 1.5 units during the test. The range of the pH was 7.28 – 8.80 during the experiment.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield
Details on results:
Based on the nominal loading rate (WAF):
The 72h EbL50 value (biomass): > 100 mg/L nominal loading rate WAF
The 72h ErL50 value (growth rate): > 100 mg/L nominal loading rate WAF
The 72h EyL50 value (yield): > 100 mg/L nominal loading rate WAF

The 72h No Observed Effect Loading Rate (NOELR):
100 mg/L nominal loading rate WAF
The 72h Lowest Observed Effect Loading Rate (LOELR):
> 100 mg/L nominal loading rate WAF
Based on the measured test item concentration:
The 72h EbC50 value (biomass): > 100 mg/L (measured)
The 72h ErC50 value (growth rate): > 100 mg/L (measured)
The 72h EyC50 value (yield): > 100 mg/L (measured)

The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (measured)
The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (measured)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The effect of EXT. AQ. CONC. PLANTULE AVOINE was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum), over an exposure period of 72 hours.

Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of EXT. AQ. CONC. PLANTULE AVOINE were the following:
Based on the nominal loading rate (WAF):
The 72h EbL50 value (biomass): > 100 mg/L nominal loading rate WAF
The 72h ErL50 value (growth rate): > 100 mg/L nominal loading rate WAF
The 72h EyL50 value (yield): > 100 mg/L nominal loading rate WAF

The 72h No Observed Effect Loading Rate (NOELR):
100 mg/L nominal loading rate WAF
The 72h Lowest Observed Effect Loading Rate (LOELR):
> 100 mg/L nominal loading rate WAF
Based on the measured test item concentration:
The 72h EbC50 value (biomass): > 100 mg/L (measured)
The 72h ErC50 value (growth rate): > 100 mg/L (measured)
The 72h EyC50 value (yield): > 100 mg/L (measured)

The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (measured)
The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (measured)