Reaction mass of 1,5-dihydroxy-4-nitro-8-(phenylamino)anthraquinone and 1,8-dihydroxy-4-nitro-5-(phenylamino)anthraquinone

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:

Study initiation date: September 28, 1995 to Study completion date: October 10, 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

None

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 concentrations in the test according to the guidelines). - 4 instead of 5 test concentrations

GLP compliance:

yes

Specific details on test material used for the study:

Code number: FAT 92504/A
Batch-Nr.: 1/95
Purity: 46 %
Appearance: solid
Solubility: <0.1 g/l [in water]
Storage: room temperature
Expiration date: 04/99

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Organism: Activated sludge of a communal sewage treatment plant (ARA-Pro Rheno Basel), collected on October 3, 1995.
Sludge pretreatment: 3 times washing with tap water and addition of synthetic sewage feed (a day before the main test).

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20 ± 2 °C

pH:

7.8 before the test beginning

Nominal and measured concentrations:

Test concentrations : 320, 100, 32 and 10 mg/l of the test substance.
32, 10 and 3.2 mg/l of the reference substance.

Details on test conditions:

Experimental conditions
Temperature: 20 ± 2 °C
Sludge dry weight: 1.44 g/l
Test volume: 100 ml
Test duration: 3 h
Aeration: 0.1 - 0.2 l/min by Pasteur-pipette
pH of sludge: 7.8 before the test beginning
Estimation technic: O2 - consumption, measured with an oxygen sensitive electrode system: OXI DIGI 530 (SAV : 00 109)

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol for synthesis (Merck 821768)

Key result

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

Details on results:

The % inhibition observed was 0, 2.5, 0 and 0 % at 10, 32, 100 and 320 mg/L, respectively.

Results with reference substance (positive control):

The IC50 (3 h) of the reference substance 3,5-Dichlorophenol: 14 mg/l

Validity criteria fulfilled:

yes

Conclusions:

IC50 (3 h) of the test substance FAT 92504/A was determined to be >320 mg/l.

Executive summary:

The toxicity of FAT 92504/A to activated sludge was determined in a 3-hours respiration inhibition test according to the EEC Directive 87/302, L 133/118 -122 and to the OECD Guideline No. 209. The test substance concentrations tested were 320, 100, 32 and 10 mg/l. The reference substance, 3,5-Dichlorophenol was tested in concentrations of 32, 10 and 3.2 mg/l. The % inhibition observed was 0, 2.5, 0 and 0 % at 10, 32, 100 and 320 mg/L, respectively. Based on the findings of the study, IC50 (3 h) of the test substance FAT 92504/A was determined to be >320 mg/l, while the IC50 (3 h) of the reference substance 3,5-Dichlorophenol was 14 mg/l.

Description of key information

The toxicity of FAT 92504/A to activated sludge was determined in a 3-hours respiration inhibition test according to the EEC Directive 87/302, L 133/118 -122 and to the OECD Guideline No. 209. The test substance concentrations tested were 320, 100, 32 and 10 mg/L. The % inhibition observed was 0, 2.5, 0 and 0 % at 10, 32, 100 and 320 mg/L, respectively. Based on the findings of the study, IC50 (3 h) of the test substance FAT 92504/A was determined to be >320 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L