7-chloro-5-(2-chlorophenyl)-1,3-dihydro-2-oxo-2H-1,4-benzodiazepin-3-yl acetate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

7-chloro-5-(2-chlorophenyl)-1,3-dihydro-2-oxo-2H-1,4-benzodiazepin-3-yl acetate

EC Number:

220-653-7

EC Name:

7-chloro-5-(2-chlorophenyl)-1,3-dihydro-2-oxo-2H-1,4-benzodiazepin-3-yl acetate

Cas Number:

2848-96-6

Molecular formula:

C17H12Cl2N2O3

IUPAC Name:

7-chloro-5-(2'-chlorophenyl)-2-oxo-2,3-dihydro-1H-1,4-benzodiazepin-3-yl acetate

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

The sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was 3.4 g/L in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (30-90 minutes) and the liquid decanted for use as inoculum at the amount of 10 ml/L of mineral medium.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

21.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Test duration: 28 days (last CO2-measurement on the 29th day). During the test period aeration and stirring takes place.
Test vessels: 2 Litre all-glass brown coloured bottles.
Milli-RO./ Milli-Q water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).
Bariumhydroxide: 0.0125 M, will be stored in a sealed vessel to prevent absorption of CO2 from the air.
CO2-free air: A mixture of oxygen (ca. 20%) and nitrogen (ca. 80%) will be led through a bottle, containing 0.5- 1 litre 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts. The CO2-free air will be sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).
Test concentration: The test substance will be tested in duplicate at a concentration corresponding to 10-20 mg TOC, DOC or TC/I. The organic carbon content will be based on either the molecular formula or on analysis of TOC, DOC or TC.
pH: 7.4 ± 0.2 (measured just before the start of the test)
Temperature: 22 ± 2°C (recorded daily during the test period in a vessel with water in the same room)
Sampling frequency: 0, 2, 5, 7, 9, 14, 19, 23, 27 and 29 days

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

1

Sampling time:

5 d

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

10

Sampling time:

14 d

% Degradation 3

Parameter:

% degradation (CO2 evolution)

Value:

14

Sampling time:

23 d

% Degradation 4

Parameter:

% degradation (CO2 evolution)

Value:

16

Sampling time:

29 d

Details on results:

The relative degradation values calculated from the measurements performed during the test period revealed 14 and 19% degradation of Wy4088 for A and B respectively. Thus, the criterion for ready biodegradability (at least 60% biodegradation within the 10-day window) was not met.

BOD5 / COD results

Results with reference substance:

The positive control substance was degraded at least 60% (80%) within 14 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Wy4088 was not readily biodegradable under the conditions of the modified Sturm test presently performed.