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Environmental fate & pathways

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Biodegradation in water :

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo]naphthalen-2-amine (CAS no. 93964 -07 -9) 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  N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo]naphthalen-2-amine is expected to be not readily biodegradable.

Additional information

Biodegradation in water :

Predicted data study for the target compound N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo]naphthalen-2-amine (CAS No. 93964-07-9) and supporting weight of evidence studies for its read across substance were reviewed for the biodegradation end point which are summarized as below:

In a prediction using the Estimation Programs Interface Suite (EPI suite, 2017),N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo] naphthalen-2-amine (CAS no. 93964 -07 -9) the biodegradation potential of the test compound in the presence of mixed populations of environmental microorganisms was estimated.

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo]naphthalen-2-amine (CAS no. 93964 -07 -9) 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  N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo] naphthalen-2-amine is expected to be not readily biodegradable.

 

The above predicted data was supported by experimental study summarized in Japan Chemical Collaborative Knowledge database (J check, 2017 ) the test chemical Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl)azo]toluene-4-sulphonate] was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analysed by using BOD parameter. The initial concentration of test chemical was 100 mg/L. After 2 weeks (14 days) test chemical Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl)azo]toluene-4-sulphonate] showed 0 % biodegradability by BOD parameterand by taking activated sludge as inoculumin 14 daysso it is concluded that test chemical Barium bis[2-chloro-5-[(2-hydroxy-1-naphthyl) azo]toluene-4-sulphonate] is not readily biodegradable.

Further to support predicted data study for target chemical another experimental study was reviewed from peer reviewed journal, in this study an experiment was conducted to determine biodegradability of test chemical Sodium 3-hydroxy-4-[(2-hydroxynaphthyl)azo]-7-nitronaphthalene-1-sulphonate by analyzing its ThOD, BOD, COD, TOC and BOD5/TOC ratio. The COD measurement was performed by the potassium dichromate reflux method based on Japanese Industrial Standards.

In the BOD measurement, a sample solution was taken into a container. Then JIS-BOD testing solutions, i.e. 3 ml of A solution and 1 ml of B, C, D solutions were added to the sample solution, respectively. Then 5 ml of the supernatant of the municipal sewage activated sludge was added to the Sample solution and diluted to 300 ml with water. Immediately, the BOD-time curve was recorded at 20oC using an Ohkura OM-200I type coulometer. The TOC measurement was carried out by a Yanagimoto TOC-ILW. The ThOD, COD, BOD, TOC and BOD5/TOC ratio determined be 1.24, 0.83, 0.143, 0.33, and 0.43 respectively. on the basis of BOD5/TOC ratio value it is concluded that test chemical Sodium3-hydroxy-4-[(2-hydroxynaphthyl)azo]-7-nitronaphthalene- 1-sulphonate A shows high resistance to aerobic degradation it means it is not readily biodegradable in aerobic condition.

On the basis of above results for target chemical N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl)azo]phenyl]azo]naphthalen-2-amine (CAS No. 93964-07-9) (from EPI suite, 2017) and for its read across substance, it can be concluded that the test substance N-(2-ethylhexyl)-1-[[2-methyl-4-[(4-methylphenyl) azo]phenyl] azo]naphthalen -2-amine can be expected to be not readily biodegradable in nature