Reaction mass of pentasodium 2-{[4-chloro-6-(ethyl{3-[(2-sulfonatoethyl)sulfonyl]phenyl}amino)-1,3,5-triazin-2-yl]amino}-5-hydroxy-6-({2-sulfonato-4-[(4-sulfonatophenyl)diazenyl]phenyl}diazenyl)naphthalene-1,7-disulfonate and tetrasodium 2-[(4-chloro-6-{ethyl[3-(vinylsulfonyl)phenyl]amino}-1,3,5-triazin-2-yl)amino]-5-hydroxy-6-({2-sulfonato-4-[(4-sulfonatophenyl)diazenyl]phenyl}diazenyl)naphthalene-1,7-disulfonate

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:

13 February 2006 to 18 April 2006

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:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identity: FAT 40824/A
Batch: Red ROE 805 BOP 04/05
Appearance: dark red powder
Purity: Organic part (Na-salt): approx. 82 %; Main component 1 : approx. 36.2 %; Main component 2: approx. 27.5 %; Oligomers: 10%
Expiration date: 01 October 2010
Stability in water: Max. 7 days at room temperature
Solubility in water: >100g/Lat20°C
Storage: At room temperature at about 20 °C, in a desiccator because test substance is hygroscopic, away from direct sunlight

Analytical monitoring:

no

Details on sampling:

No data

Vehicle:

no

Details on test solutions:

A limit test with a nominal concentration of 1000 mg/L was performed to the test item.
The nominal concentrations of the reference item were 5, 16 and 50 mg/L.

Test organisms (species):

activated sludge

Details on inoculum:

The aerobic activated sludge was from a wastewater treatment plant treating predominantly domestic wastewater.
The sludge was washed twice with tap water by centrifugation.
The final sludge suspension was dried and weighed to calculate the ratio of wet to dry weight.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Hardness:

No data

Test temperature:

20 °C

pH:

7.8 - 8.6

Dissolved oxygen:

8.1 - 9.0 mg/L

Salinity:

No data

Nominal and measured concentrations:

No data

Details on test conditions:

Test vessel: 2000 mL glass beakers
Test volume: 500 mL
The inoculum had a sludge concentration of 4 g dry weight and 200 mL of the activated sludge inoculum were added to each test vessel.
All test vessels were continuously aerated by intense stirring on magnetic stirrers.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: the result of test item

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: the result of test item

Details on results:

The test item had no significant inhibitory effect on the respiration rate of activated sludage.

Results with reference substance (positive control):

The 3-hour EC50 of the reference item was 24 mg/L, which was within the guideline recommended range of 5 - 30 mg/L.

Reported statistics and error estimates:

The inhibitory effect of the test item and the reference item on the respiration rate was expressed as a percentage of the mean respiration rate of the two controls, measured at the start and at the end of the test series.
The 3-hour EC50 of the test item could not be calculated because of the absence of an inhibitory effect on activated sludge microorganisms.
The 3-hour EC50 of the reference item was calculated by Probit Analysis.

TOXICITY OF FAT 40824/A

At the limit test concentration of 1000 mg/L, FAT 40824/A was completely dissolved and the test medium was colored red-orange.

The test item FAT 40824/A had no significant inhibitory effect (<15%) on the respiration rate of activated sludge after the incubation period of three hours at the limit test concentration of 1000 mg/L. Thus, the 3-hour NOEC of FAT 40824/A to activated sludge microorganisms is at least 1000 mg/L. The 3-hour EC20, EC50 and EC80 could not be calculated, but are clearly higher than 1000 mg/L.

The oxygen consumption rates of the two controls (run at the start and at the end of the test) differed by 7% (guideline-recommended maximum variation: 15%).

 

TOXICITY OF 3,5-DICHLOROPHENOL (POSITIVE CONTROL)

The 3-hour EC50 of the reference item 3,5-dichlorophenol (positive control) was calculated to be 24 mg/L (the 95% confidence limits were not calculable). The 3-hour EC50 is within the guideline-recommended range of 5 - 30 mg/L, thus confirming suitability of the activated sludge used.

.

Validity criteria fulfilled:

yes

Conclusions:

A limit test with a nominal concentration of 1000 mg/L was performed to demonstrate that the test item had no toxic effect on activated sludage microorganisms. Thus, the 3-hour NOEC was at least 1000 mg/L. The 3-hour EC20, EC50 and EC80 could not be calculated, but were clearly higher than 1000 mg/L.

Executive summary:

In a GLP compliant study, the inhibitory effect of the test item FAT 40824/A on the respiration rate of aerobic wastewater microorganisms of activated sludge was investigated in a 3-hour respiration inhibition test according to the EU Commission Directive 88/302/EEC, Part C.11, and the OECD Guideline for Testing of Chemicals, No. 209. In accordance with the EL) Commission Directive 92/69/EEC (C.1, C.2, and C.3), a limit test with a nominal concentration of 1000 mg/L was performed to demonstrate that the test item has no toxic effect on activated sludge microorganisms up to and including this concentration. In addition, two controls and three different concentrations of the reference item 3,5-dichlorophenol (5, 16, and 50 mg/L) were tested in parallel. The results of these treatments confirmed suitability of the activated sludge and the method used.

The test item FAT 40824/A had no significant inhibitory effect (<15%) on the respiration rate of activated sludge after the incubation period of three hours at the limit test concentration of 1000 mg/L. Thus, the 3-hour NOEC of FAT 40824/A to activated sludge microorganisms is at least 1000 mg/L. The 3-hour EC20, EC50 and EC80 could not be calculated, but are clearly higher than 1000 mg/L.

Description of key information

The IC50 and NOEC towards toxicity to microorganisms (3 hours exposure) was IC50 and NOEC ≥1000 mg/l.

 

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

1 000 mg/L

Additional information

In a GLP compliant study, the inhibitory effect of the test item FAT 40824/A on the respiration rate of aerobic wastewater microorganisms of activated sludge was investigated in a 3-hour respiration inhibition test according to the EU Commission Directive 88/302/EEC, Part C.11, and the OECD Guideline for Testing of Chemicals, No. 209. In accordance with the EL) Commission Directive 92/69/EEC (C.1, C.2, and C.3), a limit test with a nominal concentration of 1000 mg/L was performed to demonstrate that the test item has no toxic effect on activated sludge microorganisms up to and including this concentration. In addition, two controls and three different concentrations of the reference item 3,5-dichlorophenol (5, 16, and 50 mg/L) were tested in parallel. The results of these treatments confirmed suitability of the activated sludge and the method used.

The test item FAT 40824/A had no significant inhibitory effect (<15%) on the respiration rate of activated sludge after the incubation period of three hours at the limit test concentration of 1000 mg/L. Thus, the 3-hour NOEC of FAT 40824/A to activated sludge microorganisms is at least 1000 mg/L. The 3-hour EC20, EC50 and EC80 could not be calculated, but are clearly higher than 1000 mg/L.