Tetrahydrogen [29H,31H-phthalocyanine-2,9,16,23-tetrasulphonato(6-)-N29,N30,N31,N32]cobaltate(4-)

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:

protocol 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:

protocol adaptations: see below

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

protocol adaptations: see below

Deviations:

no

Principles of method if other than guideline:

As the test item is a water soluble 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:

Tetrahydrogen [29H,31H-phthalocyanine-2,9,16,23-tetrasulphonato(6-)-N29,N30,N31,N32]cobaltate(4-)

EC Number:

238-200-7

EC Name:

Tetrahydrogen [29H,31H-phthalocyanine-2,9,16,23-tetrasulphonato(6-)-N29,N30,N31,N32]cobaltate(4-)

Cas Number:

14285-59-7

Molecular formula:

C32H16CoN8O12S4

IUPAC Name:

tetrahydrogen [29H,31H-phthalocyanine-2,9,16,23-tetrasulphonato(6-)-N29,N30,N31,N32]cobaltate(4-)

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: 22.5 – 22.8 °C
Temperature in the climate chamber: 21.0 - 23.2 °C.

pH:

pH: 7.30 – 7.64

Nominal and measured concentrations:

The following nominal concentrations were determined according to a range-finding test: 1.0, 2.0, 4.0, 8.0, 16.0 and 32.0 mg/L.
The test item concentrations were analytically determined at the start and at the end of the experiment. Concentrations at the two lowest test levels could not be measured at the end of the test caused by interfered by the algae cells, moreover at the nominal concentration of 4.0 mg/L the measurement could be interfered by the algae cells as well. Taking into account details above biological results are related to the nominal test item concentrations.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

9.12 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:

NOEC

Effect conc.:

2 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:

LOEC

Effect conc.:

4 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:

EC50

Effect conc.:

8.54 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:

NOEC

Effect conc.:

2 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:

LOEC

Effect conc.:

4 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: EC50 = 9.12 mg/L, NOEC = 2.0 mg/L and LOEC = 4.0 mg/L, results corrected taking into account the test item's coloration. This coloration has a negligible effect on results.