[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:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

method adaptations: see below

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

Version / remarks:

method adaptations: see below

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

method adaptations: see below

Deviations:

no

Principles of method if other than guideline:

Even if the test item is poorly soluble, as it is a deep-coloured powder, the amount of light for photosynthesis is likely to be significantly affected by the shading effect of the coloured test solution. The test was modified in order to separate any physical effect of the coloured material from its true toxic effects.
A spectral analysis of appropriate concentrations was made to show the absorption of light at the wavelengths required by chlorophyll.
The purpose of this test method was to compare the algae growth of algal cells which are in contact with the test item solution, and the growth of algal cells where the test item solution is placed as a light filter in front of the algae suspension, without contact with algae. To assure the appropriate position of the test solutions, two superposed flat flasks (which are open for the light only from above) were used per replicate for this experiment.
Three groups were tested: control group, treated group (algal cells which are directly in contact with the test item solution) and light filter group . The test was performed with six replicates in the control group and three replicates per treated and light filter group in each concentration level.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of Trihydrogen [29H,31H-phthalocyaninetrisulphonato(5-)-N29,N30,N31,N32]cobaltate(3-) and [29H,31H-phthalocyaninato-N29,N30,N31,N32]cobalt and dihydrogen [29H,31H-phthalocyaninedisulphonato(4-)-N29,N30,N31,N32]cobaltate(2-) and hydrogen [29H,31H-phthalocyaninesulphonato(3-)-N29,N30,N31,N32]cobaltate(1-)

Molecular formula:

C32H16N8Co(SO3)n with n=0 to 3

IUPAC Name:

Reaction mass of Trihydrogen [29H,31H-phthalocyaninetrisulphonato(5-)-N29,N30,N31,N32]cobaltate(3-) and [29H,31H-phthalocyaninato-N29,N30,N31,N32]cobalt and dihydrogen [29H,31H-phthalocyaninedisulphonato(4-)-N29,N30,N31,N32]cobaltate(2-) and hydrogen [29H,31H-phthalocyaninesulphonato(3-)-N29,N30,N31,N32]cobaltate(1-)

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

Test temperature in the flask: 22.7 – 22.8 °C
Temperature in the climate chamber: 21.5 - 23.1 °C

pH:

pH: 7.54 – 7.95

Nominal and measured concentrations:

The following nominal concentrations were determined according to a range-finding test: 1.0, 3.1, 10.0, 31.3 and 100.0 mg/L nominal loading rate WAFs.
Concentrations with the exception of the highest test level (100.0 mg/L nominal loading rate WAF) could not be measured during the experiment caused by limitation of the analytical method used. Taking into account details above biological results are related to the nominal loading rates WAFs (water accommodated fraction) based on OECD TG NO. 23 on poorly soluble and multi-constituent substances.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

27.49 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Corrected result

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

3.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Corrected result

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

LOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Corrected result

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

26.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Non-corrected result

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

3.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Non-corrected result

Effect concentrations 6

Duration:

72 h

Dose descriptor:

LOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Non-corrected result

Details on results:

Corrected results: Effects observed when algal cells were in contact with the test item solution directly were corrected with effects caused by light absorption (where the test item solution is placed as a light filter in front of the algae suspension, without contact with algae).
Non-corrected: Results are based on effects observed when algal cells were in contact with the test item solution directly (test item treated group).

The results of this experiment evidence that the test item was inhibitory to algal growth. The majority of the observed inhibition effect was not related to the light absorption by the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item was inhibitory to algal growth rate: EL50 = 27.49 mg/L, NOELR = 3.1 mg/L and LOELR = 10.0 mg/L, after correction taking into account the test item's coloration. The coloration had a negligible effect on results.