4-anilino-3-nitro-N-phenylbenzenesulphonamide

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:

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:

yes

Remarks:

preparation of the inoculum: higher sludge weight after the washing procedure (sludge concentration in the test according to the guidelines); 4 instead of 5 test conc.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Code number: 36'014/F
EN/Batch: 292347.26
Purity: 90.7 %
Appearance: solid
Solubility: < 1 g/l [in water]
Storage: room temperature
Expiration date: 04/98

Analytical monitoring:

no

Details on sampling:

No data

Vehicle:

yes

Details on test solutions:

Since the test substance swam at the surface of the medium, the stock solution was prepared by adding one drop of the emulsifier Tween 80 (concentration 35.2 mg/L). The highest solvent concentration used in the test (22.53 mg/L) was additionally tested as solvent control.

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge from ARA Pro Rheno Basel (communal sewage treatment plant).
Pretreated by washing 3 times with tap water and addition of synthetic sewage (one day before main test).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Remarks on exposure duration:

None

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

20.9 °C

pH:

7.9-8.1

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

Nominal concentrations: 0, 10, 32, 100 and 320 mg/L

Details on test conditions:

Sludge dry weight: 1.5 g/L
Test volume: 100 mL
Estimation technique: O2-consumption, measured with an oxygen sensitive electrode system: OXI DIGI 530 (SAV: 00 109)
Aeration: 0.1 - 0.2 L/min by pasteur-pipette
pH of sludge: 7.6 before the test beginning

Reference substance (positive control):

yes

Remarks:

(3,5-dichlorophenol)

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 320 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

see below

Results with reference substance (positive control):

- Results with reference substance valid? : Yes
- Relevant effect levels: 3h IC50 = 13.5 mg/L

Reported statistics and error estimates:

No data

Results:

Control	pH after 3h	1) O2 -consumption (in cm)	2) time (in cm)	mg O2 / min/L	Legend: C =Control; 1) 2 cm=0.8 mg/L O2; 2) 2 cm= 1 minute
C1 C2	8.1 8.0	4.6 4.5	3.7 3.8	0.99 0.95	ΦC 0.97 C1/C2 : 4.21% C2/C2 : 4.04%

 

Test substance(mg/L)	pH after 3h	1) O2 -consumption (in cm)	2) time (in cm)	mg O2 pro minute/L	% of control	% inhibition
320	7.9	4.9	4.1	0.96	98.97	1.03
100	8.0	4.7	4.0	0.94	96.91	3.09
32	8.0	4.8	4.1	0.94	96.91	3.09
10	8.1	4.5	3.8	0.95	97.94	2.06

 

3,5- Dichlorophenol (mg/L)	pH after 3h	1) O2-consumption (in cm)	2) time (in cm)	mg 0 2 pro minute/L	% of control	% inhibition
32	8.2	1.2	5.6	0.17	17.53	82.47
10	8.1	3.7	5.0	0.59	80.82	39.18
3.2	8.1	4.4	4.2	0.84	86.60	13.40

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the IC50 of the test substance was determined to be > 320 mg/L (i.e. > 290 mg a.i./L). The 3 h IC50 for the reference substance was 13.5 mg/L.

Executive summary:

A study was conducted to determine the toxicity of the test substance (of 90.7% purity) to activated sludge according to OECD Guideline 209 in compliance with GLP. Sludge from a domestic wastewater treatment plant was exposed for 3 h at 0, 10, 32, 100 and 320 mg/L. The reference substance 3 -5, dichlorophenol was also tested at 3.2, 10 and 32 mg/L. Under the study conditions, the 3 h IC50 was > 320 mg/L (i.e. > 290 mg a.i./L). The 3 h IC50 for the reference substance was 13.5 mg/L.

Description of key information

The 3-hour IC50 of FAT 36014 to activated sludge micro-organisms was determined to be >320 mg/L (i.e. > 290 mg a.i./L)

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L

Additional information

The key study was performed to evaluate the inhibitory effect of the test item FAT 36014 on the respiration rate of aerobic wastewater micro-organisms of activated sludge in a 3-hour respiration inhibition test according to the OECD Guideline for Testing of Chemicals, No. 209. Thus, the 3-hour IC50 of FAT 36014 to activated sludge micro-organisms was determined to be >320 mg/L (i.e. > 290 mg a.i./L). Several other studies performed between 1971 to 1983 reported 3-hour IC50 to be > 400 mg/L (i.e. ca. > 216 mg a.i./L).