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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Stability

Hydrolysis

The hydrolysis study of 2-chloro-p-phenylenediamine was predicted using OECD QSAR toolbox version 3.3 (2017) to predict the hydrolysis half-life of test compound 2-chloro-p-phenylenediamine (CAS No.615-66-7).The half-life of 2-chloro-p-phenylenediamine was estimated to be 167.64 days at temperature 25 degC, indicating that the substance 2-chloro-p-phenylenediamine is not hydrolysable.

 

Biodegradation

Biodegradation in water: screening tests

Biodegradation, the degradation of a chemical substance by the action of microorganisms, is estimatedby EPI Suite using seven models contained in BIOWIN. Version 4.10 designates these models asfollows:

Probability of Rapid Biodegradation:

Biowin1: linear regression probability model

Biowin2: nonlinear regression probability model

Expert Survey Biodegradation:

Biowin3: expert survey ultimate biodegradation model

Biowin4: expert survey primary biodegradation model

MITI Biodegradation Probability:

Biowin5: MITI linear regression model

Biowin6: MITI nonlinear regression model

Anaerobic Biodegradation Probability

Biowin7: anaerobic biodegradation model

Biodegradability estimates made by these models are based on fragment constants that were developed

using multiple linear or non-linear regression analyses.

Results from the BIOWIN evaluation of 2-chloro-p-phenylenediamine indicate that the chemical is not readily biodegradable.

 

Biodegradation in water and sediment: simulation tests

Based on the Estimation Programs Interface Suite (EPI Suite, 2017) prediction model, the half-life inwater and sediment for the test compound 2-chloro-p -phenylenediamine (CAS No.615-66-7) is estimated.If released into the environment, 21.2% of the chemical will be partitioning into the water according tothe Mackay level III fugacity model having an estimated half-life of 37.5 days (900 hrs.). Based on thishalf-life it is considered that the substance will qualify as not persistent as the half-life does not exceedthe threshold of 40 days (to qualify the chemical as persistent in water medium) as per Annex XIII ofreach regulation and also it is considered that the exposure risk to aquatic animals is moderate to low.Whereas the half-life period of 2-chloro-p-phenylen ediamine in sediment medium is estimated to be 337.5 days (8100 hrs). Therefore it is considered that the substance will qualify as very persistent as the half-life exceeds the threshold of 180 days (to qualify the chemical as very persistent in sediment medium) as per Annex XIII of reach regulation. However, as the percentage release of the test chemical into the sediment is reported as 0.0965%, indicates that 2-chloro-p-phenylenediamine is not expected to be persistent in sediment medium.

 

Biodegradation in soil

Based on the Estimation Programs Interface Suite (EPI Suite, 2017) prediction model, the half-life period in soil for the test substance 2-chloro-p-phenylene diamine (CAS No.615-66-7) is estimated. If released into the environment,78.7% of the chemical will be partitioning into the soil according to the Mackay Level III Fugacity Model having an estimated half-life period of 75 days (1800 hrs.). Based on this half-life it is considered that the substance will qualify as not persistent as the half-life does not exceed the threshold of 120 days (to qualify the chemical as persistent in soil medium) as per Annex XIII of Reach regulation and also it is considered that the exposure risk to soil dwelling animals is moderate to low.

 

Bioaccumulation

Bioaccumulation: aquatic / sediment

The BCFBAF program v3.01 of Estimation Programs Interface (EPI) Suite (2017) prediction model was used to predict the bioconcentration factor of 2-chloro-p-phenylenediamine (CAS No. 615-66-7). The bioconcentration factor (BCF) for 2-chloro-p-phenylenediamine is estimated as 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000 as per Annex XIII of REACH regulation. Thus, it is concluded that 2-chloro-p-phenylene diamine (CAS No. 615-66-7) does not qualify as bio-accumulative substance. This BCF also suggests the potential for bioconcentration in aquatic organisms is low.

 

Transport and distribution

Adsorption / desorption

The Soil Adsorption Coefficient (Koc) of 2-chloro-p-phenylenediamine was estimated using the EPI suite KOCWIN Program (v2.00). The Soil Adsorption Coefficient (Koc) of 2-chloro-p-phenylenediamine was estimated as 55.39 L/kg (log Koc = 1.7434) by means of MCI method. The results indicate that the chemical 2-chloro-p-phenylenediamine (CAS No.615-66-7) is likely to to show low tendency of sorption to soil and sediment and show moderate migration potential to groundwater.

Additional information

Stability

Hydrolysis

In a different studies, 2-chloro-p-phenylenediamine (CAS No.615-66-7) has been investigated for its hydrolysis potential to a greater or lesser extent. These include predicted and experimental study for target substance 2-chloro-p-phenylenediamine (CAS No.615-66-7) and for its closest read across substances 3-Chloroaniline (CAS No.- 108-42-9), 2,4,6-trichloroaniline (CAS No.- 634-93-5) and 3,4-Dichloroaniline (CAS No.- 95-76-1) by considering its structure-activity relationships, were reviewed and are summarized as follows:

 

The hydrolysis study of 2-chloro-p-phenylenediamine was predicted using OECD QSAR toolbox version 3.3 (2017) to predict the hydrolysis half-life of test compound 2-chloro-p-phenylenediamine (CAS No.615-66-7).The half-life of 2-chloro-p-phenylenediamine was estimated to be 167.64 days at temperature 25 degC, indicating that the substance 2-chloro-p-phenylenediamine is not hydrolysable.

 

Supported by the study from an authoritative database (Hazardous Substances Data Bank (HSDB, 2017) for a read across substance 3-Chloroaniline (CAS No.- 108-42-9).The substance 3-Chloroaniline (CAS No.- 108-42-9) is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups.

 

In addition, the study from the same authoritative database (Hazardous Substances Data Bank (HSDB, 2017) indicates that the substance 2,4,6-trichloroaniline (CAS No.- 634-93-5) is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups.

 

Moreover, the substance 3,4-Dichloroaniline (CAS No.- 95-76-1) is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups . (HSDB, 2017)

 

Based on the above available studies for the target and read across substance, it can be concluded that the test substance 2-chloro-p-phenylenediamine (CAS No.615-66-7) is not expected to undergo hydrolysis in the environment i.e., it is not hydrolysable.

 

Biodegradation

Biodegradation in water: screening tests

The biodegradation potential of the test compound 2-chloro-p-phenylenediamine (CAS No. 615-66-7) was investigated to a greater or lesser extent. Various biodegradation studies for the target substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and for its relevant read across substances such as 3 -chloroaniline (CAS No.- 108-42-9) and 2,4,6-trichloroaniline (CAS No. 634-93-5) by considering its structure-activity relationships, were reviewed and are summarized as follows:

 

The biodegradation potential of the test compound 2-chloro-p-phenylenediamine (CAS No. 615-66-7) in the presence of mixed populations of environmental microorga nisms, is estimated by Estimation Programs Interface Suite (EPI suite, 2017) using seven models contained in BIOWIN Version 4.10. Thus, results from the BIOWIN evaluation of 2-chloro-p-phenylenediamine indicate that the chemical is not readily biodegradable. 

 

The above study is supported by the data from an authoritative database such as Japan chemicals collborative knowledge database (J-check, 2010), the biodegradat ion study was conducted for 28 days for evaluating the biodegradability potential of test substance 3 -chloroaniline (CAS No.- 108-42-9). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 1, 3 and 0% by BOD, TOC removal and HPLC parameters in 28 days. Thus, based upon the study it can be concluded that 3 -chloroaniline is not readily biodegradable in water. 

 

Moreover, in a 28-days Manometric respirometry test following the OECD guideline 301F was conducted by SSS (2016) to determine the ready biodegradability of the test item 2,4,6-trichloroaniline (CAS No. 634-93-5). The test system included control, test item and reference item. The concentration of test and reference item (Sodium Benzoate) chosen for the study was 100mg/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 BOD 28 value of 2,4,6-trichloroaniline (CAS No. 634-93-5) was observed to be 0.023 mgO2/mg. ThOD was calculated as 0.896 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 22 ± 2°C according to manometric respirometry test was found to be 2.57%.  

Based on the results, the test item, under the test conditions, was found to be not readily biodegradable at 22 ± 2°C over a period of 28 days.

 

Based on the above predicted and experimental studies for target substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and read across substances such as 3 -chloroaniline (CAS No.- 108-42-9) and 2,4,6-trichloroaniline (CAS No. 634-93-5) by applying weight of evidence approach, it is concluded that the test substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) is expected to be not readily biodegradable under test conditions.

 

Biodegradation in water and sediment: simulation tests

Based on the Estimation Programs Interface Suite (EPI Suite, 2017) prediction model, the half-life inwater and sediment for the test compound 2-chloro-p-phenylenediamine (CAS No.615-66-7) is estimated.If released into the environment, 21.2% of the chemical will be partitioning into the water according tothe Mackay level III fugacity model having an estimated half-life of 37.5 days (900 hrs.). Based on thishalf-life it is considered that the substance will qualify as not persistent as the half-life does not exceedthe threshold of 40 days (to qualify the chemical as persistent in water medium) as per Annex XIII ofreach regulation and also it is considered that the exposure risk to aquatic animals is moderate to low.Whereas the half-life period of 4-chloro-o-phenylenediamine in sediment medium is estimated to be 337.5 days (8100 hrs). Therefore it is considered that the substance will qualify as very persistent as the half-life exceeds the threshold of 180 days (to qualify the chemical as very persistent in sediment medium) as per Annex XIII of reach regulation. However, as the percentage release of the test chemical into the sediment is reported as0.0965%, indicates that 2-chloro-p-phenylenediamine is not expected to be persistent in sediment medium.

 

Biodegradation in soil

Based on the Estimation Programs Interface Suite (EPI Suite, 2017) prediction model, the half-life period in soil for the test substance 2-chloro-p-phenylenediamine (CAS No.615-66-7) is estimated. If released into the environment,78.7% of the chemical will be partitioning into the soil according to the Mackay Level III Fugacity Model having an estimated half-life period of 75 days (1800 hrs.). Based on this half-life it is considered that the substance will qualify as not persistent as the half-life does not exceed the threshold of 120 days (to qualify the chemical as persistent in soil medium) as per Annex XIII of Reach regulation and also it is considered that the exposure risk to soil dwelling animals is moderate to low.

 

Bioaccumulation

Bioaccumulation: aquatic / sediment

The substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) has been investigated for its environmental bioconcentration potential (BCF) to a greater or lesser extent. These include various predicted result from validated model for target chemical 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and experimental data for its read across substances 3-chloroaniline (CAS No.- 108-42-9) and 3,4-dichlo roaniline (CAS No.- 95-76-1) by considering its structure-activity relationships. The studies are summarized as follows:

 

The BCFBAF program v3.01 of Estimation Programs Interface (EPI) Suite (2017) prediction model was used to predict the bioconcentration factor of 2-chloro-p-phenylenediamine (CAS No. 615-66-7). The bioconcentration factor (BCF) for 2-chloro-p-phenylenediamine is estimated as 3.162 L/kg wet-wt.

 

In a study conducted byT. Tsuda et al. (Chemosphere 1993, 26(12), 2301-2306.), the bioconcent ration factor (24-336 hr exposure) for carp exposed to 14.7 and 0.67 µg/L under continuous flow-through conditions, 0.8 and 2.2, respectively. Whole-body excretion rate constant 0.21 hr-1. This low value of BCF indicates that 3-chloroaniline does not qualify as bio-accumulative substance as the BCF factor is less than the bio-concentration threshold of 2000 as per Annex XIII of REACH regulation. This BCF also suggests the potential for bioconcentration in aquatic organisms is low.

 

Moreover, based on the study from an authoritative database [HSDB(Hazardous Substances Data Bank) (2017)], a BCF of 30.2 was determined for 3,4-dichloroaniline under static conditions with 60 male zebra fish for 10 hours. According to a classification scheme, this BCF suggests the potential for bioconcen tration in aquatic organisms is low.

 

Based on the above predicted studies for target substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and to its read across substances 3-chloroaniline (CAS No.- 108-42-9) and 3,4-dichloroaniline (CAS No.- 95-76-1), the bioconcentration factor (BCF) was found to be in the range of 0.8 – 30.2 (dimension less or L/kg wet-wt) at temperature 25 degC. These BCF values does not exceed the bioconcentration threshold of 2000 as per Annex XIII of REACH regulation. Thus, it is concluded that 2-chloro-p-phenylenediamine (CAS No. 615-66-7) does not qualify as bio-accumulative substance. This BCF also suggests the potential for bioconcentration in aquatic organisms is low.

 

Transport and distribution

Adsorption / desorption

Various adsorption studies for the target substance 2-chloro-p-phenylenediamine (CAS No.615-66-7) and for its read across substances 3-chloroaniline (CAS No.- 108-42-9) and 3,4-dichloroaniline (CAS No.- 95-76-1) by considering its structure-activity relationships, were summarized as follows:

 

The Soil Adsorption Coefficient (Koc) of 2-chloro-p-phenylenediamine was estimated using the EPI suite KOCWIN Program (v2.00). The Soil Adsorption Coefficient (Koc) of 2-chloro-p-phenylenediamine was estimated as 55.39 L/kg (log Koc = 1.7434) by means of MCI method. The results indicate that the chemical 2-chloro-p-phenylenediamine (CAS No.615-66-7) is likely to to show low tendency of sorption to soil and sediment and show moderate migration potential to groundwater.

 

Another Predicted data for soil adsorption coefficient of 2-chloro-p-phenylenediamine (CAS No.615-66-7) is generated using the ACD/Labs Percepta Platform - PhysChem Module. The soil adsorption coefficient i.e Koc of test substance 2-chloro-p-phenylenediamine was estimated to be 77.11 (Log Koc = 1.88) and 94.22 (Log Koc = 1.94) at pH 5.5 and 7.4 and at temperature 25 deg C. The results indicate that the chemical 2-chloro-p-phenylenediamine (CAS No.615-66-7) is likely to show low tendency of sorption to soil and sediment and show moderate migration potential to groundwater.

 

Based on the study from an authoritative database [HSDB(Hazardous Substances Data Bank) (2017)], an estimated adsorption coefficient (Koc) value of 250, determined from a log Kow of 1.88 and a regression-derived equation, indicates that 3-chloroaniline (CAS No.- 108-42-9) is expected to have moderate mobility in soil.

 

Moreover, based on the study from a same authoritative database [HSDB(Hazardous Substances Data Bank) (2017)], a Koc value of 193 (log Koc= 2.29) was measured during a batch adsorption test with a silt loam soil. According to a classification scheme, this Koc value suggests that 3,4-dichloroaniline (CAS No.- 95-76-1) is expected to have moderate mobility in soil.

 

Thus based on the above studies for target substance 2-chloro-p-phenylenediamine and the read across substance and by applying weight of evidence approach, it can be concluded that the chemical 2-chloro-p-phenylenediamine (CAS No.615-66-7) is likely to show low to moderate tendency of sorption to soil and sediment.