4,4'-bis(dimethylamino)-4''-(methylamino)trityl alcohol

Endpoint summary

Description of key information

Hydrolysis

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, it is concluded that test chemical was considered to be stable in water.

Biodegradation in water

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test chemical 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 is expected to be not readily biodegradable.

Biodegradation in water and sediment

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 3.55 % 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 180 days (4320 hrs). The half-life (180 days estimated by EPI suite) indicates that the chemical is persistentin water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of test chemical in sediment is estimated to be 1620.833 days (38900  hrs). However, as the percentage release of test chemical into the sediment is less than 6% (i.e, reported as 5.72 %), indicates that test chemical is not persistent in sediment.

Biodegradation insoil

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 90.7 % 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 360 days (8640 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to high.

Bioaccumulation: aquatic / sediment

BCFBAF model (v3.01) of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical. The bioconcentration factor (BCF) of test chemical was estimated to be 352.7 L/kg whole body w.w (at 25°C) which does not exceed the bio concentration 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. A test item solution was prepared by accurately weighing 20 mg of test item and diluted with methanol up to 10 ml. Thus, the test solution concentration was 2000 mg/l. The sample was sonicated for 5 minutes and filtered through a 0.22 µm syringe filter. The pH of the sample was found to be 7.9. Each of the reference substance and test substance were analysed by HPLC at 210 nm. For the HPLC method, HPLC model no. Agilent Technologies,1260 Infinity II was used. Column used was Cyanoprpyl (CN), 4.6*250 mm, 5 Âμm. Methanol : water (55:45) was used as a mobile phase. During the study, flow rate was 1.0ml/min. Study was performed at a temperature of 25°C. Injector volume was 20μl. Chem Station Open lab Control Panel was used as a data Acquisition software and detector wavelength taken for the study was 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 estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances 4-Chloroaniline, Toluene, 2,5-Dichloroaniline, 1-naphtol, Naphthalene, Phenanthrenea and 1,2,3-Trichlorobenzene were chosen having log Koc range from 4.166 to 10.006. The Log Koc value of test chemical was determined to be 4.386±0.010 at 25°C.This log Koc value indicates that the test chemical has a strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.

Additional information

Hydrolysis

Data available for its structurally similar read across chemicals has been reviewed to determine the hydrolysis of the test chemical. The studies are as mentioned below:

In first study it was mentined that Aromatic amines are generally resistant to aqueous environmental hydrolysis therefore,test chemical is not expected to hydrolyze in water.

In another study the test chemical is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions Therefore, test chemical was considered to be stable in water.

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, it is concluded that test chemical was considered to be hydrolytically stable.

Biodegradation in water

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

 

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

 

In a supporting weight of evidence study from study report, biodegradation study was conducted for 28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. 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 is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 0.4 mgO2/mg. ThOD was calculated as 1.31 mgO2/mg. Accordingly, the % degradation of the test chemical after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 30.53%. Based on the results, the test chemical, under the test conditions, was considered to be not biodegradable in nature.

 

For the test chemical, biodegradation study (H. Heukelekian et. al., 1955) was conducted for 5 days for evaluating the percentage biodegradability of test chemical using standard dilution method under aerobic conditions at a temperature of 20°C. Sewage was used as a test inoculum. The 5 day BOD value of test chemical was determined to be 0 g/g. Thus, based on this value, test chemical is considered to be not readily biodegradable in nature.

 

On the basis of the overall results, it can be concluded that the test chemical was considered to be not readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 3.55 % 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 180 days (4320 hrs). The half-life (180 days estimated by EPI suite) indicates that the chemical is persistentin water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of test chemical in sediment is estimated to be 1620.833 days (38900  hrs). However, as the percentage release of test chemical into the sediment is less than 6% (i.e, reported as 5.72 %), indicates that test chemical is not persistent in sediment.

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. If released into the environment, 90.7 % 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 360 days (8640 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to high.

On the basis of available information, the test chemical was considered to be not readily biodegradable in water.

Bioaccumulation: aquatic / sediment

Various predicted data for the target chemical andsupporting weight of evidence studies of its read across chemicalswere reviewed for the bioaccumulation end point which are summarized as below:

 

In a prediction done using BCFBAF model (v3.01) of Estimation Programs Interface, the bioconcentration factor (BCF) of test chemical was predicted. The bioconcentration factor (BCF) of test chemical was estimated to be 352.7 L/kg whole body w.w (at 25°C).

 

Another predicted data of test chemical was estimated using Chemspider database. The bioconcentration factor of test chemical was estimated to be 151.20 and 835.24 at pH 5.5 and 7.4, respectively.

 

The Bioconcentration factor (BCF) for test chemical was predicted in aquatic organisms by Scifinder database at pH 1-10 and temperature 25 °C. The bioconcentration factor (BCF) of test chemical was estimated to be 1, 24.1, 248, 507, 560, 566 and 567 (at 25°C) at pH 1-4, 5, 6, 7, 8, 9 and 10, respectively.

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical)  the bioaccumulation i.e BCF for test substance was estimated to be 14.3 dimensionless . The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative database (2019),the bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of test chemical in aquatic fishes. The bioaccumulation factor (BCF) value was calculated using a logKow of 0.5 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 3 dimensionless.

 

For the test chemical,bioaccumulation study was conducted on test organism Cyprinus carpio for 8 weeks for evaluating the bioconcentration factor (BCF value) of test chemical (J-CHECK, 2020). The study was performed according to other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical was prepared in HCO-40. Test chemical nominal conc. used for the study was 0.2mg/l and 0.02 mg/l, respectively. Analytical method involve therecovery ratio: Test water : 1st concentration area : 99.9 %, 2nd concentration area : 95.4 %, Fish : 89.7 %, - Limit of detection : Test water : 1st concentration area : 7.0 ppb, 2nd concentration area : 0.73 ppb, Fish : 0.04 ppm. Range finding study involve the TLm(48h) ≥ 250 ppm (w/v) on Rice fish (Oryzias latipes).The bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be in the range of 25 to 54 L/Kg at a conc. of 0.2 mg/l and 17 to 39 L/Kg at a conc. of 0.02 mg/l, respectively.

 

On the basis of above results, it can be concluded that the BCF value of test chemical was evaluated to be ranges from 1 to 835.24, respectively,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. A test item solution was prepared by accurately weighing 20 mg of test item and diluted with methanol up to 10 ml. Thus, the test solution concentration was 2000 mg/l. The sample was sonicated for 5 minutes and filtered through a 0.22 µm syringe filter. The pH of the sample was found to be 7.9. Each of the reference substance and test substance were analysed by HPLC at 210 nm. For the HPLC method, HPLC model no. Agilent Technologies,1260 Infinity II was used. Column used was Cyanoprpyl (CN), 4.6*250 mm, 5 Âμm. Methanol : water (55:45) was used as a mobile phase. During the study, flow rate was 1.0ml/min. Study was performed at a temperature of 25°C. Injector volume was 20μl. Chem Station Open lab Control Panel was used as a data Acquisition software and detector wavelength taken for the study was 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 estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances 4-Chloroaniline, Toluene, 2,5-Dichloroaniline, 1-naphtol, Naphthalene, Phenanthrenea and 1,2,3-Trichlorobenzene were chosen having log Koc range from 4.166 to 10.006. The Log Koc value of test chemical was determined to be 4.386±0.010 at 25°C.This log Koc value indicates that the test chemical has a strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.