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Environmental fate & pathways

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Description of key information

Biodegradation in water:

Biodegradability of test chemical 3-(bromomethyl)benzonitrile was estimated by using OECD QSAR tool box v3.3 and eight closest read across chemicals with log Kow as primary descriptor. Percent biodegrdation of test chemical 3-(bromomethyl)benzonitrile was estimated to be 9.1125 % by considering BOD as parameter and microorganisms as inoculum in 28 days. Based on the percent biodegradability it is concluded that this test chemical is not readily biodegradable.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3-(bromomethyl)benzonitrile (CAS no.28188 -41 -2) . If released in to the environment, 19.7 % 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 (360 hrs). The half-life (37.5days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical 3-(bromomethyl)benzonitrile 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 1% (i.e, reported as 0.327 %), indicates that test chemical 3-(bromomethyl)benzonitrile is not persistent in sediment as well.

Biodegradation in Soil:

The half-life period of test chemical 3-(bromomethyl)benzonitrile (CAS no.28188-41-2) 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, 77.2 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 3-(bromomethyl)benzonitrile in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical 3-(bromomethyl)benzonitrile, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .

Additional information

Biodegradation in water:

Two different predicted data studies for target chemical3-(bromomethyl)benzonitrile and experimental studies for its closest read across chemical with log Kow as primary descriptor have been studied for biodegradation in water endpoint and their results are summarized below.

In first weight of evidence study the Biodegradability of test chemical 3-(bromomethyl)benzonitrile was estimated by using OECD QSAR tool box v3.3 and eight closest read across chemicals with log Kow as primary descriptor. Percent biodegradation of test chemical 3-(bromomethyl)benzonitrile was estimated to be 9.1125 % by considering BOD as parameter and microorganisms as inoculum in 28 days. Based on the percent biodegradability it is concluded that this test chemical is not readily biodegradable.

In another weight of evidence study the Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 3-(bromomethyl)benzonitrile (CAS no. 28188 -41 -2) 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 3-(bromomethyl)benzonitrile is expected to be not readily biodegradable.

 

The supporting weight of evidence study was done from authoritative database (J Check, 2017) for read across chemical 1-(chloromethyl)-4-nitrobenzene (CAS no. 100-14-1) in this study the read across chemical was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analysed by using BOD and HPLC parameters. The initial concentration of read across chemical was 100 mg/L. After 4 weeks (28 days)read across chemical1-(chloromethyl)-4-nitrobenzene showed 0.0% biodegradation by HPLC parameter and 51 % biodegradation by HPLC parameter using activated sludge as inoculum in 28 days. Based on percent biodegradability by BOD parameter it is concluded that this test chemical is not biodegradable.

 

Similarly another supporting experimental weight of study was done from same source as mentioned in above study (J check, 2017) for another read across chemical 1,2-dichloro-4-(chloromethyl)benzene (CAS no. 102-47-6) In this study the read across chemical was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analysed by using BOD, TOC and GC parameters. The initial concentration of read across chemical was 100 mg/L. After 4 weeks (28 days) the read across chemical 1,2-dichloro-4-(chloromethyl)benzene showed 0.0% biodegradation by BOD and TOC parameter and 90 % biodegradation by GC parameter in 28 days. On the basis of percent biodegradation by BOD and TOC parameter it is concluded that test chemical 1,2-dichloro-4-(chloromethyl)benzene is not readily biodegradable.

On the basis of all the studies mentioned above biodegradation value by BOD parameter obtained was less than 10 % therefore it is concluded that target chemical 3-(bromomethyl)benzonitrile (CAS no. 28188 -41 -2) is expected to be not readily biodegradable in 28 days.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3-(bromomethyl)benzonitrile (CAS no.28188 -41 -2) . If released in to the environment, 19.7 % 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 (360 hrs). The half-life (37.5days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical 3-(bromomethyl)benzonitrile 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 1% (i.e, reported as 0.327 %), indicates that test chemical 3-(bromomethyl)benzonitrile is not persistent in sediment as well.

Biodegradation in Soil:

The half-life period of test chemical 3-(bromomethyl)benzonitrile (CAS no.28188 -41 -2) 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, 77.2 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 3-(bromomethyl)benzonitrile in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of test chemical 3-(bromomethyl)benzonitrile, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .