1-hydroxy-4-(p-toluidino)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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EEC Method No. L 133/118 -122

Version / remarks:

Edition : 30.05.1988

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

April 4, 1984

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Principles of method if other than guideline:

Deionized water (instead of dest. water for the stock solution); 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:

- Purity approx. 95 %
- Code number: FAT - 40504/A
- Test No.: 19-div.
- Appearance: solid
- Storage: room temperature
- Expiration date: 12/98

Analytical monitoring:

no

Details on sampling:

Test substance
- Storage: room temperature

Vehicle:

yes

Details on test solutions:

Since the test substance swam at the surface of the medium, the stock solution was prepared by adding one drop of the emulsifier Tween 80 (concentration 26.6 mg/L). The highest solvent concentrations used in the test (17.02 mg/L) was additionally tested as solvent control.

Stock solution
The stock solution was treated 20 min. in a ultrasonic bath for dispergation.

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Origin: Activated sludge of a communal sewage treatment plant (ARA - Pro Rheno Basel, Switzerland)
- Sludge pretreatment: 3 times washing with tap water and addition of synthetic sewage (a day before the main test)
- Sludge dry weight: 1.56 g/L
- pH of sludge: 7.8

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21.5°C

pH:

7.7 (concerning the highest test concentration of 320 mg/L after 3 hours)

Dissolved oxygen:

4.5 mg/L (concerning the highest test concentration of 320 mg/L after 3 hours)

Nominal and measured concentrations:

Test substance: 320, 100, 32 and 10 mg/L (nominal)
Reference substance (3,5-Dichlorophenol): 32, 10 and 3.2 mg/L

Details on test conditions:

PRE-TREATMENT OF THE STOCK SOLUTION:
- The stock solution was treated 20 min. in an ultrasonic bath for dispergation

TEST CONDITIONS:
- Test concentrations: 4 (10, 32, 100 and 320 mg/L)
- Concentrations of the reference substance: 3 (3.2, 10, 32 mg/L)
- Temperature: 21.5 °C
- Test volume: 100 mL
- Test duration: 3 h
- Estimation technique: O2 - consumption, measured with an oxygen sensitive electrode system: OXI DIGI 530 (SAV: 00 109)
- Aeration: 0.1 - 0.2 L/min by pasteur-pipette
- pH of sludge: 7.8 before the test beginning

SOLVENT CONTROL:
- Tween 80 (Fluka No. 93781)

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

Details on results:

The solvent (Tween) had no inhibitory effect on activated sludge respiration activity. After 3 hours the inhibition of the respiration rate was 2.5 % for the highest solvent concentration used in the test (17.2 mg/L).

Results with reference substance (positive control):

3,5-Dichorophenol: 3h-EC50 12.5 mg/L (test concentrations: 32,10 and 3.2 mg/l)

Solvent control

Since the test substance swam at the surface of the medium, the stock solution was prepared by adding one drop of the emulsifier Tween 80 (concentration 26.6 mg/l).

The highest solvent concentrations used in the test (17.02 mg/l) was additionally tested as solvent control.

IC50

The respiration rate of each test concentration was calculated as a percentage of the mean of the two control respiration rates. The results were plotted on a logarithmic (concentration) / normal (% inhibition) graph, where the IC50 can be evaluated.

Validity criteria fulfilled:

yes

Remarks:

respiratory rates of the 2 controls differ less than 15 % from each other; EC50 of 3,5-Dichlorophenol is in the range 2 - 25 mg/L

Conclusions:

Solvent Violet 13 was exposed to activated sludge of domestic sewage treatment plant and an 3h-IC50 of > 320 mg/L was obtained. The effect value related to nominal concentration.

Executive summary:

A study was performed to assess the toxicity of Solvent Violet 13 to microorganisms. The study was conducted according to the EEC Method No. L 133/118 -122 (Edition : 30.05.1988). The activated sludge was exposed to 4 test concentrations (10, 32, 100 and 320 mg/L). Since the substance swam at the surface of the medium, the stock solution was prepared by adding one drop of the emulsifier (Tween 80). The highest solvent concentrations used in the test (17.02 mg/L) was additionally tested as solvent control and an inhibitory effect on activated sludge respiration activity could not be detected. The respiration rate was determined after aeration periods of 3 hours. The IC50 of Solvent Violet 13 was higher than 320 mg/L. The effect value related to nominal concentration, since no analytical monitoring was performed. This toxicity study is classified as acceptable and satisfies the guideline requirements for the toxicity study to microorganisms.

Description of key information

A study was performed to assess the toxicity of Solvent Violet 13 to microorganisms according to the EEC Method No. L 133/118 -122 (Edition : 30.05.1988). The activated sludge was exposed to 4 test concentrations (10, 32, 100 and 320 mg/L). Since the substance swam at the surface of the medium, the stock solution was prepared by adding one drop of emulsifier (Tween 80). The highest solvent concentrations used in the test (17.02 mg/L) was additionally tested as solvent control and an inhibitory effect on activated sludge respiration activity could not be detected. The respiration rate was determined after aeration periods of 3 hours. The IC50 of Solvent Violet 13 was higher than 320 mg/L. The effect value related to nominal concentration, since no analytical monitoring was performed.

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L

Additional information

"Should read: IC50 > 320 mg/L"