Reaction mass of Trisodium 4-({4-chloro-6-[(4-sulfonatophenyl)amino]-1,3,5-triazin-2-yl}amino)-2-{[1-ethyl-2-hydroxy-4-methyl-6-oxo-5-(sulfonatomethyl)-1,6-dihydropyridin-3-yl]diazenyl}benzenesulfonate and Trisodium 4-({4-chloro-6-[(3-sulfonatophenyl)amino]-1,3,5-triazin-2-yl}amino)-2-{[1-ethyl-2-hydroxy-4-methyl-6-oxo-5-(sulfonatomethyl)-1,6-dihydropyridin-3-yl]diazenyl}benzenesulfonate

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 - 21 December 1992; Experiment start and end date - 05 January 1993; Study completion date - 15 January 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

Qualifier:

according to guideline

Guideline:

other: EG Method Nr.L 133/118.

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:

Code number: FAT 40000/G
Batch number: 67/92
Purity: 79.5%
Appearance: solid
Solubility: miscible
Storage: room temperature
Expiration date: 01 June 1993.

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Activated sludge of a communal sewage treatment plant

Details on inoculum:

3 times washing with tap water and addition of synthetic sewage (a day before the main test)

Test type:

other:

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20.6 °C

pH:

7.8 before the test beginning

Details on test conditions:

320,100, 32 and 10 mg/l of the test substance
32,10 and 3.2 mg/l of the reference substance

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 320 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

The % inhibition is as follows;
320 mg/L - 0%
100 mg/L - 1.20%
32 mg/L - 0%
10 mg/L - 0%

Results with reference substance (positive control):

The IC50 for 3,5- dichlorophenol was found to be 13.5 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The IC50 for FAT 40000/G was found to be greater than 320 mg/L.

Executive summary:

The toxicity of FAT 40000/G to activated sludge was determined in a 3-hours respiration inhibition test according to the OECD Guideline No. 209, and to the EG Method Nr.L 133/118.

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 IC50 for reference substance was found to be 13.5 mg/L.

The % inhibition is as follows;

320 mg/L - 0%

100 mg/L - 1.20%

32 mg/L - 0%

10 mg/L - 0%

Based on the findings, the IC50 for FAT 40000/G was found to be greater than 320 mg/L

Description of key information

The IC50 of the test substance FAT 40000 is greater than 320 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L

Additional information

The toxicity of FAT 40000 to activated sludge was determined in a 3-hour respiration inhibition test according to OECD Guideline 209. Based on the findings of the study, the IC50 of the test substance FAT 40000 is greater than 320 mg/L. Several other studies involving different batches of the test item have been conducted. In summary all came to the same results and conclusions which means that production process or batch related effects can be ruled out.

Several other supporting studies were also performed with following results:

IC50 = > 300 mg/l