2-{4-[4-[4-fluoro-6-(2-(2-vinylsulfonylethoxy)ethylamino)-1,3,5-triazin-2-ylamino]phenylazo]phenylazo}naphthalene-4,6,8-trisulfonate, trisodium salt

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:

20 March 2001 to 21 March 2001

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:

See overall remarks attachment section

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identity: FAT 40800/A
Batch number: WP 2/01
Active ingredient: ca. 70 %
Aggregate state at room temperature: Solid / powder
Color: Dark orange
Storage conditions: At room temperature at about 20 °C, away form direct sunlight
Expiration Date: February 14, 2007

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

To obtain the nominal test concentrations of: 25.6, 64.0, 160, 400 and 1000 mg test item/L the following volumes were taken from a stock solution of 2.0 g/L: 1.28, 3.2, 8, 20, and 50 mL and filled up to 100 mL with tap water after adding of 3.2 mL synthetic sewage teed and 30 mL sludge.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge of a communal sewage treatment plant (ARA Therwil) collected on March 19, 2001. The inoculum was prepared 1 day before test begin. The freshly collected activated sludge was washed 3 times with tap water. Subsequently the sludge was aerated. A sample of the activated sludge was taken to determine the dry weight of the suspended solids. The final concentrations of the inoculum was about 5.2 g/L suspended solids.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

23.2 °C

pH:

7.5 - 7.8

Nominal and measured concentrations:

Nominal: 5.6, 64.0, 160, 400 and 1000 mg/L.

Details on test conditions:

- Sludge dry weight: 1.56 g/L suspended solids.
- Test volume: 100 mL.
- Aeration: 0.1 - 0.2 L/min. by Pasteurpipette.
- Estimation technique: O2 - consumption, measured with an oxygen sensitive electrode system: OXI DIGI 530 (SOP: 00 109).

Reference substance (positive control):

yes

Remarks:

3,5 Dichlorophenol

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

A true IC50 value for the test substance could not be calculated due to a lack of effects. The IC50 (3h) of the test substance was determined at >1000 mg/L.

Results with reference substance (positive control):

IC50(3h) of 3,5 Dichlorophenol= 7. 7 mg/L.

Reported statistics and error estimates:

To calculate the inhibitory effect of the test item, its respiration rate was expressed as a percentage of the mean of two controls respiration rates.

Validity criteria fulfilled:

yes

Conclusions:

The IC50 of FAT 40800/A for microorganisms is >1000 mg/L.

Executive summary:

A GLP-compliant activitated sludge inhibition test that was performed according to the OECD 209 and EU C.11 guidelines. The test substance was tested at nominal concentrations 5.6, 64.0, 160, 400 and 1000 mg/L. Activated sludge obtained from a communal wastewater treatment plant. Test duration was 3 h. This static test was performed at 23.2 °C with test volume 100 mL and was slowly aerated. Test concentrations used were 25.6, 64, 160, 400, and 1000 mg/L of the test item while 3.2, 10, and 32 mg/L of the reference item. No effects were seen upto the highest test concentrations. Based on the test results, the IC50 of FAT 40800/A was therefore determined to be >1000 mg/L while IC50 of refernce item was 7.7 mg/L.

Description of key information

The 3-h EC50 value of test substance is >1000 mg/L in microorganisms.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

A GLP-compliant activated sludge inhibition test that was performed according to the OECD 209 and EU C.11 guidelines. The test substance was tested at nominal concentrations 5.6, 64.0, 160, 400 and 1000 mg/L. Activated sludge obtained from a communal wastewater treatment plant. Test duration was 3 h. This static test was performed at 23.2 °C with test volume 100 mL and was slowly aerated. Test concentrations used were 25.6, 64, 160, 400, and 1000 mg/L of the test item while 3.2, 10, and 32 mg/L of the reference item. No effects were seen upto the highest test concentrations. Based on the test results, the IC50 of FAT 40800/A was therefore determined to be >1000 mg/L while IC50 of reference item was 7.7 mg/L.