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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Hydrolysis:

The study does not need to be conducted because the substance is readily biodegradable.

Biodegradation in water:

28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test item. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used as a test inoculum for this study. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. 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 procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 72.28%. Degradation of Sodium Benzoate exceeds 63.25 % on 7 days & 69.27 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 0.72 mgO2/mg. ThOD was calculated as 0.87 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 82.75%. Thus on the basis of result and degradation percentage observations, it is concluded that the test chemical is readily biodegradable in nature.

 

 

Biodegradation in water and sediment:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

Biodegradation in soil:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

Bioaccumulation: aquatic/sediment:

Environmental bioconcentration factor (BCF) of the test chemical was estimated using Degradation Effects Bioconcentration Information Testing Strategies(DEBITS) Quantitative Structure-Activity Relationships (QSARs) and PBT profiler QSARs (J. D. Walkers et. al., 2002). DEBITS bioconcentration factors (BCFs) were predicted using the BCFWIN program from the Syracuse Research Corporation (SRC) EPI Suite of estimation programs.BCFs were estimated from the octanol–water partition coefficient (logP) and a series of structural correction factors. Chemicals with BCFs >1000, but <5000 were assigned a medium bioconcentration potential. Chemicals with BCFs>5000 were assigned a high bioconcentration potential.The PBT profiler’s BCFs were predicted using the BCFWIN program. Chemicals with BCFs < 5000 were assigned a medium bioconcentration potential. Chemicals with BCFs>5000 were assigned a high bioconcentration potential. The estimated BCF (bioaccumulation factor) of test chemical was determined to be 1916 dimensionless, which does not exceed the bioconcentration threshold of 2000, indicating that the chemical is considered to be non-accumulative in aquatic organisms.

 

 

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 item solution was prepared by accurately weighing 5 mg of test item and diluted with acetonitrile up to 10 ml. Thus, the test solution concentration was 500 mg/l. The pH of test substance was 6.6. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. 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 chosen according to functional similarity with the test substance and calibration graph prepared. The reference substances were Benzamide, 4-chloroaniline, Aniline, 2,5-Dichloroaniline, Naphthalene, 1,2,3-trichlorobenzene, Phenanthrene having Koc value ranging from 1.26 to 4.09. The Log Koc value of test chemical was determined to be 3.089 ± 0.000 at 25°C. This log Koc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

Additional information

Hydrolysis:

The study does not need to be conducted because the substance is readily biodegradable.

Biodegradation in water:

28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test item. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used as a test inoculum for this study. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. 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 procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 72.28%. Degradation of Sodium Benzoate exceeds 63.25 % on 7 days & 69.27 % on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 0.72 mgO2/mg. ThOD was calculated as 0.87 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 82.75%. Thus on the basis of result and degradation percentage observations, it is concluded that the test chemical is readily biodegradable in nature.

 

 

Biodegradation in water and sediment:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

 

Biodegradation in soil:

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

Bioaccumulation: aquatic/sediment:

Various experimental studies of the test chemical were reviewed for the bioaccumulation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (J. D. Walkers et. al., 2002) for the test chemical,Environmental bioconcentration factor (BCF) of the test chemical was estimated using Degradation Effects Bioconcentration Information Testing Strategies (DEBITS) Quantitative Structure-Activity Relationships (QSARs) and PBT profiler QSARs. DEBITS bioconcentration factors (BCFs) were predicted using the BCFWIN program from the Syracuse Research Corporation (SRC) EPI Suite of estimation programs. BCFs were estimated from the octanol–water partition coefficient (logP) and a series of structural correction factors. Chemicals with BCFs >1000, but <5000 were assigned a medium bioconcentration potential. Chemicals with BCFs>5000 were assigned a high bioconcentration potential. The PBT profiler’s BCFs were predicted using the BCFWIN program. Chemicals with BCFs < 5000 were assigned a medium bioconcentration potential. Chemicals with BCFs>5000 were assigned a high bioconcentration potential. The estimated BCF (bioaccumulation factor) of test chemical was determined to be 1916 dimensionless.

 

In an supporting study, Environmental bioconcentration factor (BCF) of the test chemical was estimated using the Syracuse BCFWIN of the EPIWIN model (Henrik Tyle et. al., 2002). The model is an empirically based fragmentation model, which takes into account that certain structural and molecular factors influence bioaccumulation. The estimated BCF (bioaccumulation factor) of test chemical was determined to be 1905 dimensionless.

 

For the test chemical from authoritative databases (2017), bioaccumulation study was conducted for determining the BCF (bioaccumulation factor) value of test chemical. Poecilia reticulata (guppy) (female) was used as a test organism for the study. The BCF (bioaccumulation factor) of test chemical was determined to be 703 dimensionless.

 

On the basis of above results for test chemical, it can be concluded that the BCF value of test substancewas evaluated to be upto1916,which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

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 item solution was prepared by accurately weighing 5 mg of test item and diluted with acetonitrile up to 10 ml. Thus, the test solution concentration was 500 mg/l. The pH of test substance was 6.6. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. 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 chosen according to functional similarity with the test substance and calibration graph prepared. The reference substances were Benzamide, 4-chloroaniline, Aniline, 2,5-Dichloroaniline, Naphthalene, 1,2,3-trichlorobenzene, Phenanthrene having Koc value ranging from 1.26 to 4.09. The Log Koc value of test chemical was determined to be 3.089 ± 0.000 at 25°C. This log Koc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

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