5,12-dihydroquinolino[2,3-b]acridine-7,14-dione and (mono and bis)-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-5,12-dihydroquinolino[2,3-b]acridine-7,14-dione

Toxicity to microorganisms

Administrative data

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:

other: GLP guideline study according to OECD 209

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of mono-[(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl]-5,12-dihydroquino[2,3-b]acridine-7,14-dione and di-[(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl]-5,12-dihydroquino[2,3-b]acridine-7,14-dione and 5,12-dihydroquino[2,3-b]acridine-7,14-dione

EC Number:

700-776-7

Molecular formula:

C29H17O4N3 (unspecified isomers) / C38H22O6N4 (unspecified isomers) / C20H12O2N2

IUPAC Name:

Reaction mass of mono-[(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl]-5,12-dihydroquino[2,3-b]acridine-7,14-dione and di-[(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)methyl]-5,12-dihydroquino[2,3-b]acridine-7,14-dione and 5,12-dihydroquino[2,3-b]acridine-7,14-dione

Details on test material:

- Physical state: Solid/ red
- Storage condition of test material: Ambient at room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

The test substance was added in the required amounts according to the test concentrations directly to the test vessels with about 234 mL deionized water. 16 mL synthetic medium were dosed to each test vessel with test substance afterwards. The pH-values in all test vessels were checked. An adjustment was not necessary.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: Activated sludge from the municipal wastewater treatment plant of Mannheim, Germany was collected from the aeration tank of the plant
- Preparation of inoculum for exposure: The activated sludge suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed once with drinking water and the suspension was adjusted to 3 g/L dry matter
- Pretreatment: None
- Initial biomass concentration: 1.5 g/L dry mass

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

20.7 – 21.1 °C

Dissolved oxygen:

Oxygen concentration during aeration: > 2 mg/L
Oxygen concentration immediately before measurement: > 7 mg/L

Nominal and measured concentrations:

1000, 500, 250, 125, 62.5 mg/L as nominal concentration based on test substance without correction of purity.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer-flasks (nominal volume 250 mL)
- Type (delete if not applicable): closed
- Aeration: incubation was started by aeration of the test vessels with pressure air
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates):0

OTHER TEST CONDITIONS
- Adjustment of pH: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Test concentrations: 62.5, 125, 250, 500, 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

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

Results with reference substance (positive control):

The EC50 of 3,5-dichlorophenol is in the range of 5 - 30 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations.