Tetrasodium 4-amino-5-hydroxy-6-[[2-methoxy-5-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]-3-[[4-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2,7-disulphonate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

see read across justification in section 13

Reason / purpose for cross-reference:

read-across source

GLP compliance:

yes

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

no

Hardness:

no data

Test temperature:

18 to 22°C

pH:

start: 7 to 7.4

Dissolved oxygen:

no data
activity in control: 56.7 mg O2/L/h

Salinity:

NA

Nominal and measured concentrations:

2500, 5000 and 10000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: glass bottles with ground neck NS 29, 170 mm x 60 mm diameter, volume: 480 mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- Biomass loading rate: 1.6 g/L inoculum



OTHER TEST CONDITIONS
- Adjustment of pH: 6.9 in stock solution

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorphenol: 5, 20, and 30 mg/L

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

> 5 000 mg/L

Remarks on result:

other: EC20

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 5 000 mg/L

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50: 5 to 30 mg/L

Reported statistics and error estimates:

-

Validity criteria fulfilled:

yes

Conclusions:

Remazol Schwarz B is not harmful to activated sludge. The EC50 lies above 10000 mg/L

Executive summary:

The inoculum was 1.6 g/L; the graph of the dose-effect curve shows that there is no dose-dependency at concentrations of 2500, 5000 and 10000 mg/L.

Due to the nearly parallel curve progression to the "concentration axis" it is assumed that there is definitely no inhibition up to a concentration of 5000 mg/L and most likely no inhibition at a concentration of 10000 mg/L.

Remazol Schwarz B is not harmful to activated sludge. The EC50 lies above 10000 mg/L

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

12. Jan. 1992 to 13. Jan. 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 2500, 5000 and 10000 mg/L

Vehicle:

no

Details on test solutions:

- stock solution: 10 g TS were weighed and diluted in 500 mL water. The stock solution was stirred for 2 hours at 23°C and the adjusted to pH 6.9

Test organisms (species):

activated sludge

Details on inoculum:

- Source: sewage treatment plant Frankfurt-Sindlingen
- Laboratory culture: according to EU-guideline
- Method of cultivation: according to EU-guideline
- Preparation of inoculum for exposure: according to EU-guideline
- Pretreatment: the inoculum was not acclimatized to the test substance or reference substance prior to test
- Initial biomass concentration: according to EU-guideline

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

no

Hardness:

no data

Test temperature:

18 to 22°C

pH:

start: 7 to 7.4

Dissolved oxygen:

no data
activity in control: 56.7 mg O2/L/h

Salinity:

NA

Nominal and measured concentrations:

2500, 5000 and 10000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: glass bottles with ground neck NS 29, 170 mm x 60 mm diameter, volume: 480 mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- Biomass loading rate: 1.6 g/L inoculum



OTHER TEST CONDITIONS
- Adjustment of pH: 6.9 in stock solution

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorphenol: 5, 20, and 30 mg/L

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

> 5 000 mg/L

Remarks on result:

other: EC20

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 5 000 mg/L

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50: 5 to 30 mg/L

Reported statistics and error estimates:

-

Validity criteria fulfilled:

yes

Conclusions:

Remazol Schwarz B is not harmful to activated sludge. The EC50 lies above 10000 mg/L

Executive summary:

The inoculum was 1.6 g/L; the graph of the dose-effect curve shows that there is no dose-dependency at concentrations of 2500, 5000 and 10000 mg/L.

Due to the nearly parallel curve progression to the "concentration axis" it is assumed that there is definitely no inhibition up to a concentration of 5000 mg/L and most likely no inhibition at a concentration of 10000 mg/L.

Remazol Schwarz B is not harmful to activated sludge. The EC50 lies above 10000 mg/L

Reference 3

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 03. February to 04. February 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Direct weighing
- Incubation time: 3 h with permanent aeration

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Method of cultivation: aeration tank of a waste water treatment plant treating predominantly domestic sewage (Wupper area water authority)
- Pretreatment: None
- pH of the suspension before application: 8.0
- Test concentration of the activated sludge: 320 mg/L suspended solids

Test type:

not specified

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Remarks on exposure duration:

-

Post exposure observation period:

None

Hardness:

No data

Test temperature:

20±2 °C

pH:

7.9-8.2

Dissolved oxygen:

6.4

Salinity:

No data

Nominal and measured concentrations:

Nominal: 100, 1000, 10000 mg/L

Details on test conditions:

Type of application: Direct weighing
Test concentration of the activated sludge: 320 mg/L suspended solids

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (97 % purity)

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: -

Details on results:

Test substance showed 28.5 % respiration inhibition of activated sludge at a test substance concentration of 10000 mg/L

Results with reference substance (positive control):

- Results with reference substance valid: Yes
- Ref. concentrations: 5, 10, 20 mg/L
- % Inhibition: 72.9 at 20 mg/L concentrations.
- EC50: 9.7 mg/L

Reported statistics and error estimates:

The EC values are determined by statistical methods (probit analysis).

Table 1. Results

Test concentration (mg/L)	Respiratory rate Test substance (mg/L. h)	Phys.-chem. O2-consumption (mg/L. h)	Respiratory rate Phys.-chem. O2-consumption (mg/L. h)	Inhibition (%)
100	31.0	0.0*	31.0	0.0
1000	29.1	0.0*	29.1	4.9
10000	28.5	0.0	28.5	6.9
Control, Mean	30.6
Control 1	31.2
Control 2	30.0

 

* The physico chemical oxygen consumption is determined at 10000 mg/L test substance concentration. No physico-chemical oxygen consumption has been determined. Therefore lower concentrations of the test substance cause no physico chemical oxygen consumption (deduced values).

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the test substance showed 6.9 % respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 was determined to be > 10000 mg/L.

Executive summary:

A study was performed to assess the toxicity of test substance to bacteria according to Commission Directive 88/3021EEC; Official Journal of the EC L133 Part C (1988) and equivalent to OECD Guideline 209 in compliance with GLP

 

The activated sludge was exposed to test substance at different concentrations. The respiration rate of each mixture was determined after aeration periods of 3 h. Test substance showed 6.9 % respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 was determined to be > 10000 mg/L.

 

Under the test conditions, the test substance showed 6.9 % respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 was determined to be > 10000 mg/L. 

Description of key information

The test substance is not harmful to activated sludge. The EC50 lies above 10000 mg/L

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

EC10 or NOEC for microorganisms:

10 000 mg/L

Additional information

The activated sludge was exposed to test substance at different concentrations. The respiration rate of each mixture was determined after aeration periods of 3 h. Test substance showed 6.9 % respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 was determined to be > 10000 mg/L.

 

Under the test conditions, the test substance showed 6.9 % respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 was determined to be > 10000 mg/L.