Sodium 1-amino-4-[[3-[(benzoylamino)methyl]-2,4,6-trimethylphenyl]amino]-9,10-dihydro-9,10-dioxoanthracene-2-sulphonate

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:

April 14, 1994

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:

- Deion. 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

Principles of method if other than guideline:

SAV: 05 000 02

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Test concentrations : 320,100, 32 and 10 mg/l of the test substance

Vehicle:

no

Details on test solutions:

- 0.5 g/l test substance was treated for 10 min. in a ultrasonic bath for dissolving.
- Sludge dry weight: 1.50 g/l

Test organisms (species):

other: Activated sludge of a communal sewage treatment plant (ARA - Birs 1 Reinach)

Details on inoculum:

Sludge 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:

no

Total exposure duration:

3 h

Test temperature:

21.1 °C

pH:

pH of sludge: 7.9 before the test beginning
pH of test substance after 3 h:
- 7.5 (320 mg/l of test substance)
- 7.8 (100 mg/l of test substance)
- 7.9 (32 mg/l of test substance)
- 7.9 (10 mg/l of test substance)
- 7.5 (320 mg/l of test substance)

Nominal and measured concentrations:

Nominal concentrations:
- 320,100, 32 and 10 mg/l of the test substance

Details on test conditions:

TEST SYSTEM
- Aeration: 0.1 - 0.2 l/min by pasteur-pipette
- Test volume: 100 ml

Reference substance (positive control):

yes

Remarks:

3,5 dichlorophenol

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

Duration:

3 h

Dose descriptor:

other: IC20

Effect conc.:

ca. 18.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

IC50 (3h): 12.5 mg/l

To calculate the inhibitory effect of the test substance, its respiration rate is expressed as a percentage of the mean of two control respiration rates:

[(C1+C2)/2]-Zs	x100
[(C1+C2)/2]

S = Test substance; Z = O2 -consumption; C1 = Control 1; C2 = Control 2

 

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

Conclusions:

IC50 (3h) > 320 mg/l

Executive summary:

Method:

The toxicity to microorganisms was determined by the OECD Guideline n. 209.

 

Results:

IC50 (3h) > 320 mg/l

Description of key information

IC50 > 320 mg/l

Key value for chemical safety assessment

EC50 for microorganisms:

320 mg/L

Additional information

The toxicity to microorganisms was determined by the OECD guideline n.209. The substance was tested at four concentrations : 320,100, 32 and 10 mg/l. The resulting IC50 after 3 hours was > 320 mg/l.

All the existing studies, showed consistent results summarized in the attachement.