2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]-, ar-styrenated

Endpoint summary

Description of key information

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo]phenyl]azo]-, ar-styrenated (CAS no. 85203 -90 -3) 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-Naphthalenol, 1-[[2-methyl- 4-[(2-methylphenyl)azo]phenyl]azo]-, ar-styrenated is expected to be not readily biodegradable.

Additional information

Biodegradation in water:

One predicted data study for target chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo]phenyl]azo]-, ar-styrenated (CAS no. 85203 -90 -3) and three experimental studies for its structurally similar read across chemicals have been conducted and their results are summarized below.

In first weight of evidence study the prediction was done by using Estimation Programs Interface Suite (EPI suite, 2017) in this study the biodegradation potential of the test compound 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo]phenyl]azo]-, ar-styrenated (CAS no. 85203 -90 -3) was estimated 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-Naphthalenol, 1-[[2-methyl- 4-[(2-methylphenyl)azo]phenyl]azo]-, ar-styrenated is expected to be not readily biodegradable.

Second study was experimental study done from authoritative database (HSDB, 2017) for structurally similar read across chemical in this study the test chemical showed 0.0% biodegradation by considering BOD as parameter in 5 days, and by taking sewage as inoculums. So it is concluded that read across chemical disodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate is not readily biodegradable.

Next supporting weight of evidence study was also experimental study done from authoritative database (J check, 2017) in this study test chemical 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 read across chemical was 100 mg/L. After 2 weeks (14 days) test chemical showed 0 % biodegradability by BOD parameter and by taking activated sludge as inoculumin 14 days. on the basis of percent degradability it is concluded that test chemical  is not readily biodegradable.

Last supporting weight of evidence study was also experimental study done from UERL laboratory in this study biodegradation of test chemical was determined by using 28-days Manometric respirometry test following the OECD guideline 301 F. The test system included control, test item and reference item. The concentration of read across and reference item (Sodium Benzoate) chosen for the study was 20 mg/l and 30 mg/l, while that of inoculum was 10ml/L. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % Degradation was calculated using the values of BOD and ThOD for test item and reference item. The BOD28 value of test chemical was observed to be 0.050mgO2/mg. ThOD was calculated as 1.088 mgO2/mg. Accordingly, the % degradation of the read across item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was determined to be 4.596 %. Based on the results, the test chemical, under the test conditions, was considered to be not readily biodegradable at 20 ± 1°C over a period of 28 days.

On the basis of above results for target chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo]phenyl]azo]-, ar-styrenated (CAS no. 85203 -90 -3)from ( EPI suite 2017) and for its read across substances ( from authoritative databases and UERL laboratory) the target chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo]phenyl]azo]-, ar-styrenated (CAS no. 85203 -90 -3)can be expected to be not readily biodegradable.