Tetrasodium [3-[(3-chloro-2-hydroxy-5-sulphophenyl)azo]-5-[[4-chloro-6-(3-sulphoanilino)-1,3,5-triazin-2-yl]amino]-4-hydroxynaphthalene-2,7-disulphonato(6-)]cuprate(4-)

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

Commission Regulation (EU) 2016/266

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

0 h, 72 h

Vehicle:

no

Details on test solutions:

The stock solution of the test substance was prepared in the test medium. 100 mg of the test substance was weighted into 1000 ml of the test medium for the preliminary test and 25 mg of the test substance was weighted into 250 ml of the test medium for the limit test.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM - Common name: Desmodesmus subspicatus - Strain: Brinkmann 1953/SAG 86.81 - Source (laboratory, culture collection): The Botanic Institute of the Czech Academy of Science - Age of inoculum (at test initiation): 4 months - Method of cultivation: indirect daylight at laboratory temperature

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

21 - 23°C

pH:

7.5 - 7.7

Nominal and measured concentrations:

The analytical determination of the test substance concentrations was performed at the beginning and at the end of the test. The samples for analysis were taken from the highest (100 mg/l), the lowest (1 mg/l) test concentration and from the highest concentration (100 mg/l) without algae.

Details on test conditions:

TEST SYSTEM - Test vessel: Erlenmeyer flask - Aeration: stopper venting air - Initial cells density: 5000 cells/ml - No. of vessels per concentration (replicates): 3 (preliminary test), 6 (limit test) - No. of vessels per control (replicates): 3 (preliminary test), 6 (limit test) GROWTH MEDIUM - Standard medium used: yes TEST MEDIUM / WATER PARAMETERS - Source/preparation of dilution water: deionized water - Conductivity: < 5 µS/cm - Culture medium different from test medium: no OTHER TEST CONDITIONS- Photoperiod: continuous light - Light intensity and quality: 4440 to 8880 lux TEST CONCENTRATIONS - Range finding study: 1, 5, 10, 50, 100 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate

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

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:

NOEC

Effect conc.:

< 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Tab No. 1: Mean cell density - preliminary test

nominal concentration	mean cell density in 1 ml
	0 h	24 h	48 h	72 h
100 mg/l	5000	12500	56250	104167
50 mg/l	5000	12500	58333	114583
10 mg/l	5000	14583	62500	110417
5 mg/l	5000	12500	60417	114583
1 mg/l	5000	14583	70833	125000
control	5000	20833	79167	179167

Tab No. 2: Mean cell density - limit test

nominal concentration	mean cell density in 1 ml
	0 h	24 h	48 h	72 h
100 mg/l	5000	22917	46875	106250
control	5000	23958	85417	193750

Validity criteria fulfilled:

yes

Conclusions:

EC50 > 100 mg/l (72 h, growth rate)EC50 > 100 mg/l (72 h, yield inhibition)NOEC < 100 mg/l (72 h, growth rate)NOEC < 100 mg/l (72 h, yield inhibition)

Executive summary:

The preliminary test was performed in a range of test substance nominal concentrations 1 – 100 mg/l. The analytical results showed that the test substance, Reactive Violet 1, is sufficiently stable in the test medium at conditions of the test at current concentration range. The highest inhibition of growth rate was 15.2 % and the highest inhibition of yield was 43.1 % in the preliminary test. Based on no toxicity of the test substance lower than 50 % found in the preliminary test, the limit test was performed subsequently. The concentration of 100 mg/l was tested in the limit test. The inhibition of growth rate was 16.4 % and the inhibition of yield was 46.4 %.

Test results:

EC50 > 100 mg/l (72 h, growth rate)

EC50 > 100 mg/l (72 h, yield inhibition)

NOEC < 100 mg/l (72 h, growth rate)

NOEC < 100 mg/l (72 h, yield inhibition)

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L