Disodium 6-hydroxy-5-[(2-methoxy-4-sulphonato-m-tolyl)azo]naphthalene-2-sulphonate

Endpoint summary

Description of key information

Hydrolysis:

According to the data from authoritative database, the test substance does not hydrolyze under normal environmental conditons, as it does not possess functional groups which are responsible for hydrolysis.

 

Biodegradation in water:

Predicted data for the test chemical and various supporting weight of evidence studies for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 In a prediction using the Estimation Programs Interface Suite (2018), the biodegradation potential of the test chemical in the presence of mixed populations of environmental microorganisms was estimated. 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 test chemical is expected to be not readily biodegradable.

 In a supporting weight of evidence study from experimental study report, 28-days Manometric respirometry test following the OECD guideline 301F to determine the ready biodegradability of the test chemical was conducted. Mixture of domestic waste water, surface soil and soil samples was used as a test inoculum for the study. OECD mineral medium was used for the study. The test system included control, test item and reference item. The concentration of test chemical used for the study was 45 mg/l and reference substance ( Sodium Benzoate) chosen for the study was 30 mg/L, while that of inoculum was 10 ml/l. The % degradation of procedure control (Sodium Benzoate) was also calculated using BOD & ThOD and was determined to be 74.074%. Degradation of Sodium Benzoate exceeds 50.050 % after 7 days and 68.068 % after 14 days. The BOD28 value of test chemical was observed to be 0.022 mgO2/mg. ThOD was calculated as 1.267 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C was determined to be 1.754 %.Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable at 20 ± 1°C over a period of 28 days.

 Another supporting study was performed in order to determine the ready biodegradability of the test substance, a 28-days test following the OECD guideline 301F was performed. The test system included control, test substance and reference substance. The concentration of both, test and reference substance (Sodium Benzoate) chosen for the study was 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 % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was observed to be 12.807%. Based on the results, the test item under the test condition was determined to be not readily biodegradable period of 28 days.

 

On the basis of above results for test chemical, it can be concluded that the test chemical can be expected to be not readily biodegradable in nature.

 

Bioaccumulation: aquatic/sediment:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this endpoint is scientifically not necessary and does not need to be conducted since the test chemical has a low potential for bioaccumulation based on logKow ≤ 3.

 

Adsorption / desorption:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test substance solution was prepared by accurately weighing 4 mg of test substance and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 6.9. Each of the reference substance and test substance were analysed by HPLC at 210 nm. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were Acetanilide, 4-chloroaniline, 4 -methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 -nitrophenol, 2 -nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3 -trichlorobenzene, Pentachlorophenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09.

The Log Koc value of test chemical was determined to be 1.274± 0.003 dimensionless at 25°C.This log Koc value indicates that the substance has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Additional information

Hydrolysis:

According to the data from authoritative database, the test substance does not hydrolyze under normal environmental conditons, as it does not possess functional groups which are responsible for hydrolysis.

 

Biodegradation in water:

Predicted data for the test chemical and various supporting weight of evidence studies for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 In a prediction using the Estimation Programs Interface Suite (2018), the biodegradation potential of the test chemical in the presence of mixed populations of environmental microorganisms was estimated. 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 test chemical is expected to be not readily biodegradable.

 In a supporting weight of evidence study from experimental study report, 28-days Manometric respirometry test following the OECD guideline 301F to determine the ready biodegradability of the test chemical was conducted. Mixture of domestic waste water, surface soil and soil samples was used as a test inoculum for the study. OECD mineral medium was used for the study. The test system included control, test item and reference item. The concentration of test chemical used for the study was 45 mg/l and reference substance ( Sodium Benzoate) chosen for the study was 30 mg/L, while that of inoculum was 10 ml/l. The % degradation of procedure control (Sodium Benzoate) was also calculated using BOD & ThOD and was determined to be 74.074%. Degradation of Sodium Benzoate exceeds 50.050 % after 7 days and 68.068 % after 14 days. The BOD28 value of test chemical was observed to be 0.022 mgO2/mg. ThOD was calculated as 1.267 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C was determined to be 1.754 %.Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable at 20 ± 1°C over a period of 28 days.

 Another supporting study was performed in order to determine the ready biodegradability of the test substance, a 28-days test following the OECD guideline 301F was performed. The test system included control, test substance and reference substance. The concentration of both, test and reference substance (Sodium Benzoate) chosen for the study was 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 % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was observed to be 12.807%. Based on the results, the test item under the test condition was determined to be not readily biodegradable period of 28 days.

 

On the basis of above results for test chemical, it can be concluded that the test chemical can be expected to be not readily biodegradable in nature.

 

Bioaccumulation: aquatic/sediment:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this endpoint is scientifically not necessary and does not need to be conducted since the test chemical has a low potential for bioaccumulation based on logKow ≤ 3.

 

Adsorption / desorption:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test substance solution was prepared by accurately weighing 4 mg of test substance and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 6.9. Each of the reference substance and test substance were analysed by HPLC at 210 nm. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were Acetanilide, 4-chloroaniline, 4 -methylaniline(p-Tolouidine), N-methylaniline, p-toluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 -nitrophenol, 2 -nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4-Nitrobenzamide, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3 -trichlorobenzene, Pentachlorophenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09.

The Log Koc value of test chemical was determined to be 1.274± 0.003 dimensionless at 25°C.This log Koc value indicates that the substance has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.