4H-Pyrazino[2,1-a]isoquinolin-4-one, 2-acetyl-1,2,3,6,7,11b-hexahydro-

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-12-20 to 2005-01-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

Commission Directive 92/69/EEC, Method C.4-D of July 31, 1992: Manometric Respirometry Test (EEC Publication No. L 383 A, December 1992)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: sewage plant Groß-Zimmern, Germany
- Preparation of inoculum for exposure: 2 x washing with tap water by centrifugation and decantation of the supernatant liquid
- Concentration of sludge: 1.5 g dry material
- Water filtered: no

Duration of test (contact time):

28 d

Initial conc.:

ca. 100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Preparation of Test Flasks:
The amounts of test item and reference item were directly weighed into the test flasks. No emulsifiers or solvents were used, but the solutions were dispersed by stirring to achieve a homogeneous solution of the test item.

Incubation:
The closed test flasks were incubated in a climatic chamber under continuous stirring. The consumption of oxygen was determined by measuring the change of pressure in the flasks. Evolved carbon dioxide was absorbed in an aqueous solution (45 %) of potassium hydroxide.

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

4

Sampling time:

28 d

Details on results:

Points of degradation plot (test substance): 0 % degradation after 7 d 1 % degradation after 14 d 2 % degradation after 21 d 4 % degradation after 28 d

Results with reference substance:

Points of degradation plot (reference substance):
75 % degradation after 7 d
90 % degradation after 14 d
97 % degradation after 21 d
100 % degradation after 28 d

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The degradation rate of the test item did not reach 60 % within the 10-day window and after 28 days of incubation. Therefore, the test item is considered not to be readily biodegradable.

Executive summary:

The purpose of this assay was to provide information on the biodegradability of the test item in aqueous environment according to OECD TG 301 F and thus serve as a rational basis for risk assessment for environmental fate in aqueous compartments. The test item was exposed to activated sludge from the aeration tank of a domestic waste water treatment plant for 28 days. The biodegradation was followed by the oxygen uptake of the microorganismsduring exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. This study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with activated sludge. The test item did not reach 60 % within the 10-day window and after 28 days of incubation. After 28 days a  degradation of 4 % was observed. The reference item aniline was sufficiently degraded to 90 % after 14 days, and to 112 % after 28 days of incubation. In the toxicity control containing both, the test item and the reference item, 51 % biodegradation was noted within 14 days and 55 % biodegradation was determined after 28 days of incubation. Thus the test item can be assumed to be not inhibitory on the activated sludge microorganisms.The oxygen demand in the abiotic control was 0 mg/L. The degradation rate of the test item did not reach 60 % within the 10-day window and after 28 days of incubation. Therefore, the test item is considered not to be readily biodegradable.

Description of key information

According to an OECD TG 301 F compliant study, the test item is not readily biodegradable (reference 5.2.1-1).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

Ready biodegradation

The purpose of this assay was to provide information on the biodegradability of the test item in aqueous environment according to OECD TG 301 F and thus serve as a rational basis for risk assessment for environmental fate in aqueous compartments. The test item was exposed to activated sludge from the aeration tank of a domestic waste water treatment plant for 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item aniline was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. This study is recognized by the international test guidelines and should provide a rational basis to assess the ready biodegradation properties of the test item when incubated with activated sludge. The test item did not reach 60 % within the 10-day window and after 28 days of incubation. After 28 days a  degradation of 4 % was observed. The reference item aniline was sufficiently degraded to 90 % after 14 days, and to 112 % after 28 days of incubation. In the toxicity control containing both, the test item and the reference item, 51 % biodegradation was noted within 14 days and 55 % biodegradation was determined after 28 days of incubation. Thus the test item can be assumed to be not inhibitory on the activated sludge microorganisms.The oxygen demand in the abiotic control was 0 mg/L. The degradation rate of the test item did not reach 60 % within the 10-day window and after 28 days of incubation. Therefore, the test item is considered not to be readily biodegradable.