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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Biodegradation:

Biodegradation in water:

Biodegradability of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236 -25 -8) was estimated by uisng OECD QSAR tool box v3.4 considering five closest read across chemicals with log kow as primary descriptor. The percent biodegradability of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236-25-8) was estimated to be 1.72 % by considering BOD as parameter and microorganisms as inoculum in 28 days. On the basis of percent biodegradation it can be concluded that test chemical is  2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile 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 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236 -25 -8). If released in to the environment, 16.4 % 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 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is high whereas the half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile in sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.112 %), indicates that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is not persistent in sediment.

Biodegradation in Soil:

The half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236 -25 -8) 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, 83.5 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile in soil is estimated to be 120 days (2800 hrs). Based on this half-life value of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .

Bioaccumulation:

Bioaccumulation: aquatic/sediments:

Using BCFBAF Program (v3.00) model of EPI suite (2017) the estimated bio concentration factor (BCF) for 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236-25-8) is 5.551 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is non bioaccumulative in food chain.

Transport and distribution:

Adsorption/desorption:

The Soil Adsorption Coefficient i.e. Koc value of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236-25-8) was estimated using EPI suite KOCWIN Program (v2.00) as 96.75 L/kg (log Koc= 1.9858) by means of MCI method at 25 deg. C.  This log Koc value indicates that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile has low sorption to soil and therefore test chemical has moderate migration potential to ground water.

Additional information

Biodegradation:

Biodegradation in water:

Predicted data studies for target chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236 -25 -8)and one experimental study for its structurally similar read across chemical have been conducted and their results are summarized below biodegradation in water endpoint.

 

In first predicted data study biodegradability of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236 -25 -8) was estimated by using OECD QSAR tool box v3.4 considering five closest read across chemicals with log kow as primary descriptor. The percent biodegradability of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236-25-8) was estimated to be 1.72 % by considering BOD as parameter and microorganisms as inoculum in 28 days. On the basis of percent biodegradation it can be concluded that test chemical is 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is not readily biodegradable.

 

 In another predicted data study the Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236 -25 -8) 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 Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical  2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is expected to be not readily biodegradable.

 

Next study was experimental study done from authoritative database (J check, 2017) for read across chemical 1-(4-methyl-2-nitrophenylazo)-2-naphthol (CAS no. 2425-85-6) in this study the read across chemical 1-(4-methyl-2-nitrophenylazo)-2-naphthol (CAS no. 2425-85-6) 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. The read across chemical1-(4-methyl-2-nitrophenylazo)-2-naphthol showed 0 % biodegradability by BOD parameter and 1 % by HPLC parameter and activated sludge as inoculumin 28 days. On the basis of percent degradability value it is concluded that read across chemical 1-(4-methyl-2-nitrophenylazo)-2-naphthol is not readily biodegradable.

 

On the basis of results of all the studies mentioned above it can be concluded that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS no. 12236 -25 -8) 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 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236 -25 -8). If released in to the environment, 16.4 % 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 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is high whereas the half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile in sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.112 %), indicates that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is not persistent in sediment.

Biodegradation in Soil:

The half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236 -25 -8) 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, 83.5 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile in soil is estimated to be 120 days (2800 hrs). Based on this half-life value of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low .

Bioaccumulation:

Bioaccumulation: aquatic/sediments:

Using BCFBAF Program (v3.00) model of EPI suite (2017) the estimated bio concentration factor (BCF) for 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236-25-8) is 5.551 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile is non bioaccumulative in food chain.

Transport and distribution:

Adsorption/desorption:

The Soil Adsorption Coefficient i.e. Koc value of test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile (CAS No. 12236-25-8) was estimated using EPI suite KOCWIN Program (v2.00) as 96.75 L/kg (log Koc= 1.9858) by means of MCI method at 25 deg. C.  This log Koc value indicates that test chemical 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile has low sorption to soil and therefore test chemical has moderate migration potential to ground water.