2-butyl-6-(butylamino)-1H-benz[de]isoquinoline-1,3(2H)-dione

Endpoint summary

Description of key information

Biodegradation in water:

The biodegradability of the substance was calculated using seven different Biowin 1-7 models of the BIOWIN v4.10 software. The results indicate that the test chemical 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione is expected to be not readily biodegradable.

Biodegradation in water and sediment:
Estimated half life of test chemical 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione in water was 15 days (360 h) and in sediment estimated to be 135 days (3240 h).

Biodegradation in soil:
Biodegradation half-life of test substance 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione in soil was estimated to be 30 days (720 hrs).

Additional information

Biodegradation in water:

Predicted data for the substance 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione and the experimental data of its read across substances were reviewed for the endpoint Biodegradation in water and are summarized below as weight of evidence approach:

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound  2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (CAS no. 19125 -99 -6) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione is expected to be not readily biodegradable.

The biodegradation of 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione was estimated using QSAR prediction models. Prediction was done using QSAR Toolbox version 3.4. According to the quantitative structure activity relationship(QSAR) model prediction, the substance 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione shows 6.80% degradation in 28 days. Thus it was concluded that the test compound is not readily biodegradable in water.

28 days test was carried out for the read across substance 5,5-diphenylimidazolidine-2,4-dione [synonym:phenytoin; CAS No. 57-41-0] to determine its biodegradability in water (J-check database, 2017). The concentration of the substance used was 100 mg/L and the concentration of sludge was 30 mg/L. After 28 days 1% degradation was found following BOD parameter while 2% degradation was found following HPLC parameter. These values indicates that the substance 5,5-diphenylimidazolidine-2,4-dione [synonym:phenytoin] is not readily biodegradable in water.

14 days test was carried out for other structurally similar substance N,N'-(3,3'-dimethylbiphenyl-4,4'-ylene)di(acetoacetamide); CAS No. 91-96-3; to determine its biodegradability in water (Finnish Environment database, 2017). The concentration of the substance used was 100 mg/L and the concentration of sludge was 30 mg/L. After 14 days 0% degradation was found following BOD parameter. This value indicates that the substance N,N'-(3,3'-dimethylbiphenyl-4,4'-ylene)di(acetoacetamide) is not readily biodegradable in water.

Considering above results and by applying weight of evidence approach it can be concluded that the substance 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione is expected to be not readily biodegradable.

Biodegradation in water and sediment:
Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound  2 -butyl-6 -(butylamino)-1H-benzo[de]iso quinoline-1,3(2H)-dione (CAS No.19125 -99 -6). If released in to the environment, 18.5% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3 (2H)-dione in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.73%), indicates that 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione is not persistent in sediment.

Biodegradation in soil:
The half-life period of 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (CAS No. 19125 -99 -6) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 80.7% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 2-butyl-6-(butylamino)-1H-benzo[de]isoquinoline-1,3(2H)-dione in soil is estimated to be 30 days ( 720 hrs). Based on this half-life value of 2 -butyl-6 -(butylamino)-1H-benzo[de]iso quinoline-1,3(2H)-dione, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.