Tetra(sodium/potassium)-7-[(E)-{2-acetamido-4-[(E)-(4-{[4-chlor-6-({2-[(4-fluor-6-{[4-(vinylsulfonyl)phenyl]amino}-1,3,5-triazin-2-yl)amino]propyl}amino)-1,3,5-triazin-2-yl]amino}-5-sulfonato-1-naphthyl)diazenyl]-5-methoxyphenyl}diazenyl]-1,3,6-naphthalintrisulfonate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experiment start date - 04 September 2006; Experiment completion date - 08 September 2008; Study completion date - 21 November 2006.

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 (incl. QA statement)

Specific details on test material used for the study:

Identity: FAT 40827/A
Batch: T2 5572 BOP 01/06
Purity: determined in this study
Appearance: black sticky powder
Expiration date: 28.02.2011
Storage: at room temperature

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The study was performed with aerobic activated sludge from a wastewater treatment plant (ARA Ergolz II, Füllinsdorf, Switzerland) treating predominantly domestic wastewater. The sludge was washed twice with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated. Based on this ratio, an aliquot of washed sludge was suspended in tap water to obtain a concentration equivalent to 3 g dry material per liter. During the holding period of two days prior to use, the sludge was fed daily with 50 mL synthetic wastewater per liter and was kept at room temperature under continuous aeration until use. Before use, the dry weight of the activated sludge was measured again in the inoculum used for the test. The pH of the activated sludge inoculum was adjusted from 8.1 to 7.2 with a diluted sulfuric acid solution.

Test organisms (species):

activated sludge

Details on inoculum:

Synthetic wastewater:
16 g peptone
11 g meat extract
3 g urea
0.7 g NaCI
0.4 g CaCI2 • 2H20
0.2 g MgS04 • 7H20
2.8 g K2HP04

Test type:

not specified

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Test temperature:

20 °C

pH:

7.2 - 8.1

Dissolved oxygen:

7.7-8.8 mg/L

Nominal and measured concentrations:

Nominal: 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 2000-mL glass beakers

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The test item FAT 40827/A had no significant inhibitory effect (<15 %) on the respiration rate of activated sludge after the incubation period of three hours at the limit test concentration of 1000 mg/L. Thus, the 3-hour NOEC (EC15) of FAT 40827/A to activated sludge microorganisms was at least 1000 mg/L. This value might even be higher, but concentrations above 1000 mg/L were not tested. The 3-hour EC20, EC50, and EC80 could not be calculated but were clearly higher than 1000 mg/L.

Results with reference substance (positive control):

EC50 = 14 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The test item had no inhibitory effect on the respiration rate of activated sludge after the incubation period of three hours at the test item concentration of 1000 mg/L. Thus, the 3-hour NOEC (EC15) of the test item to activated sludge microorganisms was at least 1000 mg/L. This value might even be higher but concentrations above 1000 mg/L were not tested. The 3-hour EC20, EC50, and EC80 could not be calculated, but were clearly higher than 1000 mg/L.

Executive summary:

The test was performed to determine the toxic effects of test substance on the respiration of activated sludge during 3 hours according to the OECD TG 209. Only one concentration of 1000 mg/L of test substance was applied in the definitive test. Control groups and reference substance were also applied. The results indicated 3-hour NOEC of the test item to activated sludge microorganisms was at least 1000 mg/L. This value might even be higher but concentrations above 1000 mg/L were not tested. The 3-hour EC20, EC50, and EC80 could not be calculated, but were clearly higher than 1000 mg/L.

Description of key information

The 3-hour EC20, EC50, and EC80  were higher than 1000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

1 000 mg/L

Additional information

The test was performed to determine the toxic effects of test substance on the respiration of activated sludge during 3 hours according to the OECD TG 209. Only one concentration of 1000 mg/L of test substance was applied in the definitive test. Control groups and reference substance were also applied. The results indicated 3-hour NOEC of the test item to activated sludge microorganisms was at least 1000 mg/L. This value might even be higher but concentrations above 1000 mg/L were not tested. The 3-hour EC20, EC50, and EC80 could not be calculated, but were clearly higher than 1000 mg/L.