Tetrasodium 7-[[2-[(aminocarbonyl)amino]-4-[[4-chloro-6-[[3-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]amino]-1,3,5-triazin-2-yl]amino]phenyl]azo]naphthalene-1,3,6-trisulphonate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

01 September 1998 to 04 September 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Sampling was undertaken at test start and after 72 hours of exposure.

Vehicle:

no

Details on test solutions:

Method of administration: Stock solution, 125 mg/L. No other data listed in report.

Test organisms (species):

Scenedesmus sp.

Details on test organisms:

Species: Scenedesmus subspicatus CHODAT
Origin: Institute of Plant Physiology, University of Gottingen
Cultivation (stock cultures, pre cultures, test cultures): In a light chamber at 23 ± 2°C and with a quantum flux which equals 120 μE/m2 S.
Water for dilution: deionised water

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

No post exposure period

Hardness:

No data

Test temperature:

No data

pH:

8.1 - 9.7

Dissolved oxygen:

No data

Salinity:

Not applicable.

Nominal and measured concentrations:

25, 50, 100 mg/L

Details on test conditions:

Exponentially-growing cultures of a species of green algae are exposed to various concentrations of the test substance over several generations under defined conditions.
The test solutions are incubated for a period of 72 hours, during which the cell density in each is measured at every 24 hours. The inhibition of growth and growth rate in relation to a control is determined after 72 hours of incubation.

Test procedure
Erlenraeyer flasks (300 mL) with stoppers
100 mL of test medium
light chamber and magnetic stirrer
Determination of the effects on the growth of Scenedesmus subspicatus within a 72 h exposure period.

Counting:Microcellcounter Sysmex F-300Digitana (SOP 2030-0001903-98 D)
Method of administration: stock solution (SOP 2030-6600401-9& D) (125 mg/l)
Test concentration/s: 25, 50, 100 mg/L
Inoculum: Algal suspension taken from an exponentially growing preculture which serves to adjust an initial cell density of 10 000 cells per millilitre.
Control: Inoculum in nutrient medium and water for dilution.
Water for dilution: deionised water

Reference substance (positive control):

not specified

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 101 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 101 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

101.4 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

101.4 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

The test result refers to a concentration of the test substance, which was calculated directly from analytically determined TOC values. According to the relevant product information, 1 mg/L TOC equals to 2.9 mg/L of the main component of the test substance (structural formula: C25H21N7£4014FNa3 7 molecular weight: 859 g/mol). Considering the low purity degree of the test substance (content of the main component about 50%; content of unidentified organic by products about 20% and 25% of an organic salt) the above analytical value indicate a 100% recovery rate.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

No data

MEAN CELL DENSITY AND pH VALUES DURING THE TEST

Nominal concentration test substance (mg/L)	Number of cells/mL			pH values
	24 h	48 h	72 h	0 h	72 h
Control	83300	184000	324000	8.4	9.6
25	82200	219000	418000	8.4	9.7
50	70000	173000	386000	8.3	9.7
100	94300	202000	368000	8.1	9.6

 

Growth (b) [integral of biomass] – After 72 hours of exposure

Nominal concentration test substance (mg/L)	Growth (integral of biomass)	% inhibition [+] or % increase [-] of growth (control = 0%)
Control	404000	0.0
25	485000	-20.1
50	411000	-1.7
100	455000	-12.6

 

Growth rate (r) – After 72 hours of exposure

Nominal concentration test substance (mg/L)	Growth rate (L/d)	% inhibition [+] or % increase [-] of growth rate (control = 0%)
Control	1.2	0.0
25	1.2	0.0
50	1.2	0.0
100	1.2	0.0

 

Validity criteria fulfilled:

yes

Conclusions:

ErC50 > 101.0 mg/l

Executive summary:

Method

Study conducted to test guidance "Algal growth inhibition test" Council Directive (1992) in compliance with GLP. 

Exponentially-growing cultures of a species of green algae are exposed to various concentrations of the test substance over several generations under defined conditions.

The test solutions are incubated for a period of 72 hours, during which the cell density in each is measured at every 24 hours. The growth inhibition and growth rate in relation to a control is determined after 72 hours of incubation.

The test results refer to a concentration of the test substance, which was calculated directly from analytically determined TOC values. According to the relevant product infor­mation, 1 mg/L TOC equals to 2.9 mg/L of the main component of the test substance (molecular weight: 859 g/mol).

Results 

No toxic effects against algae at 101.4 mg/L were noted on the substance tested.

Description of key information

ErC50 > 101.0 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

101 mg/L