6,18-dihydrodinaphtho[2,3-i:2',3'-i']benzo[1,2-a:4,5-a']dicarbazole-5,7,12,17,19,24-hexone

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:

22 July, 1993 to 17 August, 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:

1) Deion. water instead of dest. water for the stock solution; 2) Preparation of the inoculum : higher sludge weight after the washing procedure (Sludge concentrations in the test according to the guidelines); 3) 4 instead of 5 test concentrations

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Identification: FAT 46014 / G
- Lot/batch: 258645.16
- Purity test date: 99.8 % AS
- Apperance : Red Solid

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

No data

Test organisms (species):

activated sludge

Details on inoculum:

- Organism : Activated sludge of a communal sewage treatment plant (ARA-Birsig Therwil)
- 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:

yes

Total exposure duration:

3 h

Post exposure observation period:

None

Hardness:

Not available

Test temperature:

21.5 °C

pH:

6.2 before the test beginning

Dissolved oxygen:

Not available

Salinity:

Not available

Nominal and measured 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:

TEST SYSTEM
- Aeration:0.1 - 0.2 l/min by Pasteur-pipette

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Test volume : 100 ml
Sludge dry weight : 1.56 g/l
Estimation technique : O2 - consumption, measured with an oxygen sensitive electrode system: OXI DIGI 530 (SAV : 00 109)

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (Merck 821768)

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:

The % inhibitions observed at 1.32, 0, 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: 6.6 mg/l

Reported statistics and error estimates:

None

None

Validity criteria fulfilled:

yes

Conclusions:

The IC50 (3 h) of FAT 36034/D is determined to be greater than 320.0 mg/L.

Executive summary:

The toxicity of FAT - 46'014/G to activated sludge was determined in a 3-hours respiration inhibition test according to the OECD Guideline No. 209, and to the EEC Method No. L 133/118. The test was performed in compliance with the Good Laboratory Practice (GLP).

The % inhibitions observed at 1.32, 0, 0 and 0 % at 10, 32, 100 and 320 mg/L, respectively. Based on these findings, the IC50 (3 h) of FAT 36034/D is determined to be greater than 320.0 mg/L.

Description of key information

The IC50 (3 h) of FAT 46014/G was found to be greater than 320.0 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L

Additional information

The toxicity of FAT - 46014/G to activated sludge was determined in a 3-hours respiration inhibition test according to the OECD Guideline No. 209, and to the EEC Method No. L 133/118. The test was performed in compliance with the Good Laboratory Practice (GLP).

The % inhibitions observed at 1.32, 0, 0 and 0 % at 10, 32, 100 and 320 mg/L, respectively. Based on these findings, the IC50 (3 h) of FAT 36034/D is determined to be greater than 320.0 mg/L.

In several other supporting studies, a toxicity to activated sludge of greater than 300 mg/L was found.