Reaction product of 3,9-dibromobenzanthrone condensed with 2 equivalents of 1-aminoanthraquinone, subsequently further condensed under oxidative conditions

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:

5 February 1993 to 22 February 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:

The concentration of the test substance in the stock solution is 0.1 g/L in water, instead 0.5 g/L.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

Not performed

Vehicle:

no

Details on test solutions:

Not specified

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Organism: Activated sludge of a communal sewage treatment plant (ARA-Pro Rheno Basel)Sludge pretreatment: 3 times washing with tap water and addition of synthetic sewage (a day before the main test)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

No post exposure observation period specified

Hardness:

No data

Test temperature:

20.4°C

pH:

6.4 before the test beginning

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Nominal: 64, 20 and 6.4 mg/L of the test substance
Nominal: 32,10 and 3.2 mg/L of the reference substance

Details on test conditions:

Temperature: 20.4°C
Sludge dry weight: 1.56 g/L
Test volume: 100 mL
Test duration: 3h
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: 6.4 before the test beginning

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 64 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

Substance is miscible in water -> dispersion

Results with reference substance (positive control):

The IC50 of the reference substance 3,5-Dichlorophenol : 8.0 mg/l.

Reported statistics and error estimates:

No data

 

Control	pH after 3 h	^1) O2-consumption (in cm)	^2) time (in cm)	mg O2/min/l
C1 C1	7.6 7.5	4.2 4.2	3.8 4.1	0.88 0.82	Φ C 0.85

 

Test substance (mg/l)	pH after 3 h	^1) O2-consumption (in cm)	^2) time (in cm)	mg O2 pro min/l	% of control	% inhibition
64	7.3	4.9	4.4	0.89	104.71	0.00
20	7.5	4.5	4.2	0.86	101.18	0.00
6.4	7.6	4.3	4.1	0.84	98.62	1.18

 

3,5-Dichlorophenol (mg/l)	pH after 3 h	^1) O2-consumption (in cm)	^2) time (in cm)	mg O2 pro min/l	% of control	% inhibition
32	7.7	0.8	5.3	0.12	14.12	85.88
10	7.7	2.3	4.8	0.38	44.71	55.29
3.2	7.7	3.9	5.2	0.60	70.59	29.41

 

C = Control

¹⁾2 cm = 0.8 mg/l O₂

²⁾2 cm = 1 min

 

Remark: Substance is miscible in water → dispersion

Validity criteria fulfilled:

yes

Conclusions:

The IC50 (3 h) of the test material : > 64.0 mg/l.

Executive summary:

The toxicity of the test material to activated sludge was determined in a 3-hours respiration inhibition test according to the OECD Guideline No. 209, and performed in compliance with the Good Laboratory Practice (GLP) Regulations of Switzerland.

 

The test substance concentrations tested were 64, 20 and 6.4 mg/l. The reference substance 3,5-Dichlorophenol was tested in concentrations of 32,10 and 3.2 mg/l.

 

Results:

IC50 of the test material: > 64.0 mg/l

IC50 of the reference substance: 8.0 mg/l

Description of key information

Key value determined in a GLP accredited laboratory study performed in accordance with OECD Guideline No. 209.

Key value for chemical safety assessment

EC50 for microorganisms:

64 mg/L

Additional information

The toxicity of the substance to activated sludge was evaluated in a GLP study conducted in accordance with OECD Guideline No. 209. The substance concentrations tested were 64, 20 and 6.4 mg/L. The IC50 of the test material was determined to be > 64.0 mg/L.