N,N-diethylaniline

Endpoint summary

Description of key information

Stability:

Hydrolysis

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical can be expected to be ranges from 29 days to > 1 yr, at pH range 4-9 and at a temperature of 50-55°C or 1.1 days, respectively. Thus, based on this half-life value, it can be concluded that the test chemical undergoes slow to negligibe hydrolysis in water.

Biodegradation:

Biodegradation in water:

The test chemical was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using two parameters that are BOD and TOC. The initial concentration of test chemical was 100 mg/L and study design was of standard type. After 2 weeks test chemical showed 0.0%, and 1.0 % degradation by   BOD and parameter respectively in two weeks (14 days).On the basis of % degradation values it is concluded that test chemical is not readily biodegradable.

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, 83  % 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 37.5 days ( 900  hrs). The half-life ( 37.5 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.268 %), 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 (EPI suite, 2018). If released into the environment, 83 % 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 75 days (1800 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:

Bioaccumulation test was conducted for 8 weeks for determination the bioconcentration factor (BCF) of chemical on testorganism Cyprinus carpio.

Nominal concentrations used in the study are Nominal concentrations 1st Concentration area: 0.2 ppm(v/v), 2nd Concentration area: 0.02 ppm(v/v) and Range finding study was carried out on Rice fish (Oryzias latipes)TLm(48h) 16.8 ppm(w/v). The vehicle used in this study was HCO-40.The bioconcentration factor (BCF) for test chemical was determined in  Cyprinus carpio . The BCF value was observed to be in range 44-161 L/kg at dose concentration 0.2 mg/L and 17-125 L/kg at dose concentration 0.02 mg/L on the basis of total lipid content on test organism Cyprinus carpio during 8 weeks period. Therefore it is concluded that this test chemical is nonbioaccumulative.These range BCF values indicate that the test chemical is not bioaccumulative in fish and food chain as these values are far less than 2000 criteria.

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 pipetting 4 microlitre of test item and diluted with Acetonitrile upto 10 ml. Thus, the test solution concentration was 375.2 mg/l(calculated according to its density). The pH of test substance was 6.4. 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 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 -naphthylamine, 1-naphthol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT were chosen having Koc value range from 1.25 to 5.63.The Log Koc value of test chemical was determined to be 3.424 ± 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.

Additional information

Stability:

Hydrolysis

Data available for the test chemical has been reviewed to determine the half-life of hydrolysis as a function of pH. The studies are as mentioned below:

The half-life value of test chemical was determined at a pH range 5-9 and at a temperature of 55°C, respectively. The estimated half-life value of test chemical was determined to be ranges from 29 to 146 days. Based on the half-life values, it is concluded that the test chemical is not hydrolysable.

In an another study, the half-life of the test chemical was determined.The study was performed according to OECD Guideline 111 (Hydrolysis as a Function of pH). Percentage degradation of test chemical was determined to be 3.91%, 1.085% and 4.78% at pH 4.0, 7.0 and 9.0 & at a temperature of 50°C, respectively and the half-life value of test chemical was determined to be > 1 yr. Since the chemical is not degradable less than 10 % in this test condition, it is presumably stable in water.Thus based on this, test chemical is considered to be not hydrolysable in water.

In next study the half-life value of test chemical was determined to be 1.1 days. Thus based on the value, test chemical is considered to undergo slow hydrolysis in water.

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical can be expected to be ranges from 29 days to  > 1 yr, at pH range 4-9 and at a temperature of 50-55°C or 1.1 days, respectively. Thus, based on this half-life value, it can be concluded that the test chemical undergoes slow to negligibe hydrolysis in water.

Biodegradation:

Biodegradation in water:

Various experimental studies have been reviewed for test chemical for biodegradation in water endpoint and their results are summarized below.

The first experimental study have been reviewed from authoritative database ( J check) in this study the test chemical was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using two parameters that are BOD and TOC. The initial concentration of test chemical was 100 mg/L and study design was of standard type. After 2 weeks test chemical showed 0.0%, and 1.0 % degradation by   BOD and parameter respectively in two weeks (14 days).On the basis of % degradation values it is concluded that test chemical is not readily biodegradable.

Next study was reviewed from Sewage and Industrial Wastes journal (1955) in this study the biodegradation experiment was performed by using to OECD test guideline 301C. The percent degradation of test chemical was determined to be 0.0% in 14 days by using activated sludge as inoculum. On the basis of percent degradation value it is concluded that test chemical is not readily biodegradable in nature.

Another study was reviewed from secondary source in this study the percent biodegradation of test chemical was determined to be 0.0% by using BOD as parameter and sewage as inoculums in 5 days at 20 oC. On the basis of percent degradation value it is concluded that test chemical is not readily biodegradable in nature.

By considering results of all the studies mentioned above it is concluded that test chemical is not readily biodegradable.

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, 83  % 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 37.5 days ( 900  hrs). The half-life ( 37.5 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.268 %), 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 (EPI suite, 2018). If released into the environment, 83 % 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 75 days (1800 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:

Various experimental studies and prediction have been reviewed for test chemical for bioaccumulation endpoint in water endpoint and their results are summarized below.

First study was experimental study reviewed from authoritative database ( J -check) in this study the bioaccumulation test was conducted for 8 weeks for determination the bioconcentration factor (BCF) of chemical on test organism Cyprinus carpio. Nominal concentrations used in the study are Nominal concentrations 1st Concentration area: 0.2 ppm(v/v), 2nd Concentration area: 0.02 ppm(v/v) and Range finding study was carried out on Rice fish (Oryzias latipes) TLm(48h) 16.8 ppm(w/v). The vehicle used in this study was HCO-40.The bioconcentration factor (BCF) for test chemical was determined in  Cyprinus carpio . The BCF value was observed to be in range 44-161 L/kg at dose concentration 0.2 mg/L and 17-125 L/kg at dose concentration 0.02 mg/L on the basis of total lipid content on test organism Cyprinus carpio during 8 weeks period. Therefore it is concluded that this test chemical is nonbioaccumulative. These range BCF values indicate that the test chemical is non bioaccumulative in fish and food chain as these values are far less than 2000 criteria.

Another study was reviewed from Ecotoxicology and Environmental Safety journal (1980) in this study the BCF value of test chemical was estimated by using equation taken from Kenaga and Goring (1978). The bioaccumulation concentration factor of test chemical was estimated to be 16 dimensionless by using water solubility of test chemical. On the basis of BCF value it is concluded that test chemical is non bioaccumulative in nature.

In last study prediction was done by using BCFBAF Program (v3.00) model of EPI suite (2018) the estimated bio concentration factor (BCF) for test chemical  is 70.95 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 non-bioaccumulative in food chain.

By considering results of all the studies mentioned above it is concluded that BCF value of test chemical is in range of 16-161 L/Kg this range BCF value indicates that test chemical is non bioaccumulative in nature.

Transport and distribution:

Adsorption/desorption:

Various experimental studies have been reviewed for test chemical for Adsorption endpoint and their results are summarized below.

The first study was reviewed from experimental study report in this report 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. 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 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-naphthylamine, 1-naphthol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,N-dimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT were chosen having Koc value range from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 3.424 ± 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.

Next study reviewed from journal Chemosphere (1997) in this study an experimental was performed to determine adsorption coefficient o test chemical by using two different sludges from lab simulation in this study the test chemical solution is added to the sludge in centrifuge tubes and shaken. Thereafter the solution is centrifuged and the remaining concentration in the supernatant is measured.

The following modifications were made for sewage sludges:

1. 0.2 g dried sewage sludges were used for 50 ml test solution

2. for fresh sludges about 0.2 g (dry weight) were used in each test vessel

3. in addition to test solutions containing a 0.01 M CaC12 concentration, solutions of different water hardnesses were prepared by solving the desired concentrations of CaC12 in the test solution.

The log Koc value of test chemical was determined to be 1.68 and 1.76 dimensionless in two different sludges from lab simulation plant by using HPLC method. By considering log Koc value it is concluded that test chemical has low sorption to sludge and moderate migration potential to ground water.

 

Next study was reviewed from Ecotoxicology and Environmental Safety journal (1980) in this study the Koc value of test chemical was estimated by using equation taken from Kenaga and Goring (1978). The Koc value of test chemical was estimated to be 120 dimensionless (log Koc=2.079). By considering this log Koc value it is concluded that test chemical has low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Last study was reviewed from authoritative database (HSDB, 2017) in this study the Koc value of test chemical was estimated by using a log Kow of 3.31and a regression-derived equation. The Koc of test chemical was estimated to be 1500 dimensionless log Koc= 3.1760. By considering this log Koc value of test chemical it is concluded that test chemical has moderate sorption to soil and sediments and therefore has slow migration potential to ground water.

By considering results of all the studies mentioned above it is concluded log Koc value of test chemical is in range of 1.68 – 3.4 dimensionless. This range log Koc value indicates that the substance has a low to moderate sorption to soil and sediment and therefore has moderate to slow migration potential to ground water.