14H-benz[4,5]isoquino[2,1-a]perimidin-14-one

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:

1997-06-04 till 1997-06-06

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with acceptable restrictions.

Qualifier:

according to guideline

Guideline:

other: Official Journal of the European Communities L 133 Part C (Biodegradability: Examination of respiratory inhibition)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

- Concentrations: 1000, 1800, 3200, 5600 and 10000 mg/L

Vehicle:

no

Details on test solutions:

Direct weighings were prepared to give the different 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one concentrations.

Test organisms (species):

other: activated sludge (mixed population of different microorganisms)

Details on inoculum:

Source: laboratory system predominantly with urban waste water is operated (southern Wupperverband)
Preparation: none
pH of the culture solvent before start of the test: 7.2

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test temperature:

19.8 - 20.3 °C (including all test concentrations, control and reference substance)

pH:

6.9 - 7.1 (including all test concentrations, control and reference substance)

Dissolved oxygen:

5.0 - 5.4 mgO2/L at the start of the test (including all test concentrations, control and reference substance)
2.8 - 3.3 mgO2/L at the end of the test (including all test concentrations, control and reference substance)
8.1 mg /L O2-respiration

Nominal and measured concentrations:

- Concentrations: 1000, 1800, 3200, 5600 and 10000 mg/L
- Concentration of activated sludge: 400 mg/L (because of the strong oxygen consumption of the activated sludge used, only a concentration of 0.4 g/L was used in all approaches.)
- Concentration in the control: 10000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol (purity = 97 %)

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 10 000 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):

Reference substance (3,5-Dichorophenol)
Concentrations: 2.5, 5, 10, 20 and 40 mg/L
EC50 = 8.8 mg/L

Results:

Concentration	Respiration rate Test item	Respiration rate abiotic O2	Inhibition
(mg/L)	(mg/L*h)	(mg/L*h)	(%)
1000	21.0	21.0	10.6
1800	20.0	20.0	14.9
3200	19.5	19.5	17.0
5600	18.0	18.0	23.4
10000	18.0	18.0	23.4
control mean	23.5
control 1	24.0
control 2	23.0

The abiotic O₂ -consumption was determined at a concentration of 10000 mg/L.

Since no abiotic O₂-consumption was obtained no consumption at lower concentrations is expected.

Validity criteria fulfilled:

yes

Remarks:

(-Respiratory rates of the 2 controls differ less than 15 % from each other. - The EC50 of the reference compound 3,5- dochlorophenol is in the range 5 - 30 mg/L.)

Conclusions:

The respiration rate with activated sludge of14H-benz[4,5]isoquino[2,1-a]perimidin-14-one was determined an an EC50 of >10000 mg/L after 30 min.

Executive summary:

In order to test the toxicity to microorganism (activated sludge, mixed population of different microorganisms ) of 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one was determined according to the EU-Method L 133 Part C "Biodegradability: Examination of respiratory inhibition" (equivalent to OECD Guideline No. 209, "Activated sludge, Respiration Inhibition Test). Five concentrations (1000, 1800, 3200, 5600 and 10000 mg/L), control and a positive reference substance (3,5-dichlorophenol) were exposed for a period of 30 min. An EC50 of > 10000 mg/L was obtained on 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one related to respiration rate.

Description of key information

In order to test the toxicity to microorganism (activated sludge, mixed population of different microorganisms ) of 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one was determined according to the EU-Method L 133 Part C "Biodegradability: Examination of respiratory inhibition" (equivalent to OECD Guideline No. 209, "Activated sludge, Respiration Inhibition Test). Five concentrations (1000, 1800, 3200, 5600 and 10000 mg/L), control and a positive reference substance (3,5-dichlorophenol) were exposed for a period of 30 min. An EC50 of > 10000 mg/L was obtained on 14H-benz[4,5]isoquino[2,1-a]perimidin-14-one related to respiration rate.

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

The key value should read as EC50 >= 10,000 mg/L as there was no effect.