Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Stability:

Hydrolysis:

According to annex VII column 2 the study does not need to be conducted because the substance is readily biodegradable.

Biodegradation:

Biodegradation in water:

28-days Closed Bottle test following the OECD guideline 301 D was performed 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 inovulum. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32ml/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 79.51 %. Degradation of Sodium Benzoate exceeds 42.16 % on 7 days &  63.25 on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.8 mgO2/mg. ThOD was calculated as 1.25 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 76 %. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 14.1 % 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 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 0.721 %), indicates that test chemical is not persistent in sedimen

Biodegradation in Soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2018). If released into the environment, 84.4 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 120days (2880 hrs). Based on this half-life value of test chemical, 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 (2018) the estimated bioconcentration factor (BCF) for test chemical is 162.2 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical  is nonbioaccumulative in food chain.

Transport and distribution:

Adsorption/desorption:

The Adsorption Coefficient of test substance was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 2.748 ± 0.000 dimensionless at 25°C. Thus based on the result it is concluded that the test substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Additional information

Stability:

Hydrolysis:

According to annex VII column 2 the study does not need to be conducted because the substance is readily biodegradable.

Biodegradation:

Biodegradation in water:

28-days Closed Bottle test following the OECD guideline 301 D was performed 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 inovulum. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32ml/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 79.51 %. Degradation of Sodium Benzoate exceeds 42.16 % on 7 days &  63.25 on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.8 mgO2/mg. ThOD was calculated as 1.25 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 76 %. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI Suite, 2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 14.1 % 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 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 0.721 %), indicates that test chemical is not persistent in sedimen

Biodegradation in Soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2018). If released into the environment, 84.4 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 120days (2880 hrs). Based on this half-life value of test chemical, 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:

Predicted data study for target chemical and experimental studies for its structurally similar read across chemicals have been reviewed for bioccumulation endpoint and their results are summarized below

In first study using BCFBAF Program (v3.00) model of EPI suite (2018) the estimated bioconcentration factor (BCF) for test chemical was determined to be 162.2 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000.

To support above prediction experimental study was reviewed from authoritative database in this study the bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using a log Kow of 1.9 and a regression derived equation.

The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 8.0 dimensionless.

Last study was also reviewed from authoritative database in this study the bioaccumulation study in aquatic organisms was conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using a log Kow of 3.15 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 3 dimensionless.

The BCF values of all above mentioned studies does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is considered to be non-bioaccumulative in aquatic organisms.

Transport and distribution:

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 4 mg of test item and diluted with Acetonitrile up to 10ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 6.3. 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(Annex - 2).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 Benzoic acid methylester, Xylene, Ethylbenzene, Toluene, Naphthalene, Benzoic acid phenylester, were chosen having Koc value range from 1.8 to 2.87 .

The Log Koc value of test chemical was determined to be 2.748 ± 0.000 dimensionless at 25°C.This log Koc value indicates that the substance has a moderate sorption to soil and sediment and therefore has slow migration potential to ground water.