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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Remarks:
study is in progress
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
Report Date:
2018

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes
Remarks:
Reconstituted algal growth medium (OECD medium, according to OECD 201)

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Strain number: 61.81 SAG (identical strains: CCAP 278/4; UTEX 1648; ATCC 22662)

Study design

Test type:
semi-static
Water media type:
other: Reconstituted algal growth medium (OECD medium, according to OECD 201)
Limit test:
yes
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 22.6 – 22.7 °C measured in the flask and between 21.6 and 23.3 °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 7.68 – 8.76 during the experiment.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EC50
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:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield
Key result
Duration:
72 h
Dose descriptor:
NOEC
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:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Results with reference substance (positive control):
The 72h ErC 50: 0.88 mg/L, (95 % confidence limits: 0.81 – 0.96 mg/L)
The 72h EbC 50: 0.63 mg/L, (95 % confidence limits: 0.58 – 0.69 mg/L)
The 72h EyC 50: 0.53 mg/L, (95 % confidence limits: 0.49 – 0.58 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of ACIDE HYDROXY were the following:
The 72h EbC50 value (biomass): > 100 mg/L (nominal)
The 72h ErC50 value (growth rate): > 100 mg/L (nominal)
The 72h EyC50 value (yield): > 100 mg/L (nominal)
The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)
The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)
Executive summary:

The effect of ACIDE HYDROXY test item was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata, over an exposure period of 72 hours.

Because a toxic response was not observed during the preliminary concentration range-finding test, a Limit Test was carried out using only one test concentration of 100 mg/L (nominal) and one control group.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 96.1 mg/L at the start and 92.6 mg/L at the end of the experiment.

As the analytically measured concentration deviated not more than 20 per cent from the nominal, the biological results are based on the nominal test item concentration.

The test design included six replicates at test concentration and six replicates for the untreated control.

Statistical comparisons of biomass, average specific growth rates and yield in control and in treated groups were carried out using 2 Sample t-Test (α = 0.05) by TOXSTAT software.

The ErC50, EbC50 and EyC50 values of the test item were determined directly from the raw data.

Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of ACIDE HYDROXY were the following:

The 72h EbC50 value (biomass): > 100 mg/L (nominal)

The 72h ErC50 value (growth rate): > 100 mg/L (nominal)

The 72h EyC50 value (yield): > 100 mg/L (nominal)

The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)