Reaction products of Sodium 1-amino-4-bromo-9,10-dioxoanthracene-2-sulphonate coupled with Aniline, subsequently coupled with p-(1,1-dimethylpropyl)phenol, subsequently coupled with Ethyl benzoylacetate, subsequently coupled with Fuming Sulfuric acid, sodium salts.

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:

July from 06th to 08th, 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

adopted April 4, 1984

GLP compliance:

not specified

Details on test solutions:

The test article was dissolved in distilled water at a concentration of 500 mg/l.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source: aerobic activated sludge from a domestic waste-water treatment plant, ARA, Sissach/Switzerland.
- Pretreatment: the sludge was coarse sieved, centrifuged, the supernatant liquid phase decanted, the solid material resuspended in tap water and again centrifuged. The procedure was repeated a further two times.
- Preparation of inoculum for exposure: an aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge (ml) to its dry weight (g) determined. A volume of washed sludge suspension corresponding to 4.0 g dry material were made up with Soerensen buffer (pH = 7) to 1 litre. 50 ml OECD recommended synthetic sewage feed were added.
- Incubation: the sludge was incubated overnight at 20 - 25 °C, under aeration.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Nominal and measured concentrations:

10 and 100 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: glass-flasks (> 500 ml).
- Aeration: aeration with about 0.7 l/minute.
- No. of vessels per concentration: 1 replicate.
- No. of vessels per control: 2 replicates.
- Activated sludge amount per flask: 200 ml.

SAMPLING FOR ANALYSIS
After 180 minutes of-aeration, the first sample was taken for oxygen measurement over a period of up to 10 minutes. Thereafter, in 15 ninutes-intervals, the rest of the samples were submltted to measurement of oxygen concentration.
Sampling was started with the control 1. Thereafter, the measurements were continued with the positive controls and the test article samples. Finally, the oxygen consumption of control 2 was determined.

EFFECT PARAMETERS MEASURED
Oxygen consumption was measured over a period of 10 minutes. During measurement, the sample was not aerated but continuously stirred on a magnetic stirret.
The apparatus used for oxygen measurements was the WTW OXI 91 (Wissenschaftlich-Technische Werkstaetten, Weilheim/Federal Republic of Germany).
The pH was determined with the pH 90 (WTW, Weilheim/FRG).

VALIDATION OF THE TESTS
The tests are validated by testing a known standard, i.e.3,5-dichlorophenol. The reference substance IC50-value should be in the range of 5 - 30 mg/l.
Furthermore, the variation between the two control samples (start, end) should not be greater than 15 % of their mean.

Reference substance (positive control):

yes

Remarks:

dichlorophenol

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

The test article showed no inhibitory of the respiration rate (i.e. -33.3 %) up to the concentration of 100 mg/l.

Results with reference substance (positive control):

IC50 (3h): 12 mg/l

Influence of test article and reference substance on oxygen consumption of activated sludge

Terst vessel	Oxygen consumption (mgO2/l min)	Inhibition (%)	Starting pH
Control	0.42	-	7.5
Control	0.42	-	7.6
Mean	0.42 ± 0
Test item 10 mg/l	0.40	4.8	7.6
Test item 100 mg/l	0.56	-33.3	7.6
Dichlorophenol 3.2 mg/l	0.44	-4.8	7.5
Dichlorophenol 10 mg/l	0.11	73.8	7.5
Dichlorophenol 50 mg/l	0.02	95.2	7.5

Validity criteria fulfilled:

yes

Remarks:

the reference substance IC50-value resulted in the range of 5 - 30 mg/l; furthermore, the variation between the two control samples was lower than 15 % of their mean

Conclusions:

IC50 (3h) > 100 mg/l

Executive summary:

The test material was tested in accordance with the OECD Guideline for Testing of Chemicals, No. 209. The inhibitory potential effect of test item was investigated in a respiration test, using activated sludge from a sewage works treating predominantly domestic sewage.

The test article showed no inhibitory of the respiration rate (i.e. -33.3 %) up to the concentration of 100 mg/l.

Conclusion

IC50 (3h) > 100 mg/l

Description of key information

IC50 (3h) > 100 mg/l

Additional information

The test material was tested in accordance with the OECD Guideline for Testing of Chemicals, No. 209. The inhibitory potential effect of test item was investigated in a respiration test, using activated sludge from a sewage works treating predominantly domestic sewage.

The test article showed no inhibitory of the respiration rate (i.e. -33.3 %) up to the concentration of 100 mg/l.