4,7-dichloroquinoline

Endpoint summary

Description of key information

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite) was run to predict the biodegradation potential of the test compound  in the presence of mixed populations of environmental microorganisms. The biodegradability of the test chemical 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 was expected to be not readily biodegradable.

Biodegradation in water and sediment:

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 15.9% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 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 test chemical in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 5% (i.e, reported as 3.72%), indicates that test chemical is not persistent in sediment.

Biodegradation in soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 78.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical, 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.

Additional information

Biodegradation in water:

Predicted data and experimental studies for the test chemical and structurally and functionally similar read across chemical have been reviewed and their results are summarized as below for biodegradation in water endpoint.

Estimation Programs Interface Suite (EPI suite) was run to predict the biodegradation potential of the test compound  in the presence of mixed populations of environmental microorganisms. The biodegradability of the test chemical 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 was expected to be not readily biodegradable.

Above study further supported by the second weight of evidence study from authoritative database. Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test substance.  Test conducted in accordance with the "Biodegradation test of a chemical substance using a microorganism etc." provided in "the Notice on the Test Method Concerning New Chemical Substances" for 28 hours. The percentage degradation of test substance was determined 0% degradation by O2 consumption, DOC removal, Test mat. analysis and HPLC parameter in 28 days. Thus, based on percentage degradation, test chemical was considered to be not readily biodegradable in water.

Similar biodegradation study was conducted for 4 weeks for evaluating the percentage biodegradability of test substance. 30ppm sludge concentration was used in th study. 100 ppm initial test substance concentration was used. The percentage degradation of test substance was determined to be 0%, 1 % and 9% degradation by BOD, TOC removal and HPLC parameter respectively in 4 weeks. Thus, based on percentage degradation, test chemical was considered to be not readily biodegradable in water.

Thus based on the above all studes from various sources, it was concluded that the test chemical was not readily biodegradable in water.

Biodegradation in water and sediment:

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 15.9% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 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 test chemical in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 5% (i.e, reported as 3.72%), indicates that test chemical is not persistent in sediment.

Biodegradation in soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 78.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical, 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.