[No public or meaningful name is available]

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 guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Test guideline 2

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

Test material information

Constituent 1

Reference substance name:

Avena Sativa leaf/stem extract

IUPAC Name:

Avena Sativa leaf/stem extract

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella 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 concentrations

Effect concentrations 1

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

Effect concentrations 2

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

Effect concentrations 3

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)