3,5-diaminobenzoic acid

Endpoint summary

Description of key information

Biodegradation in water

Biodegradability of 3,5-Diaminobenzoic acid is predicted using QSAR toolbox version 3.4 (2017). Test substance undergoes 33.25% degradation by CO2 evolution parameter in 28 days. Thus, based on percentage degradation, the test chemical 3,5-Diaminobenzoic acid was estimated to be not readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3,5-Diaminobenzoic acid (CAS No. 535 -87 -5). If released in to the environment, 35% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 3,5-Diaminobenzoic acid 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 moderate to low whereas the half-life period of 3,5-Diaminobenzoic acid 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 0.0835%), indicates that 3,5-Diaminobenzoic acid is not persistent in sediment.

Biodegradation in soil

The half-life period of 3,5-Diaminobenzoic acid (CAS No. 535 -87 -5) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 64.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 3,5-Diaminobenzoic acid in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 3,5-Diaminobenzoic acid, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Bioaccumulation: aquatic / sediment:

The estimated bio concentration factor (BCF) for 3,5 Diaminobenzoic acid is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000.Thus it is concluded that 3,5 Diaminobenzoic acid is not expected to bio accumulate in the food chain.

Adsorption / desorption:

The adsorption coefficient Koc in soil and in sewage sludge 3,5-diaminobenzoic acid(CAS No.535-87-5) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to functional similarity with the test substance and calibration graph was prepared. The reference substances were 4 -chloroaniline, 2 - nitrophenol, Nitrobenzene, 4-Nitrobenzamide, Benzamide having Koc value ranging from 1.239 to 2.47 The Log Koc value was found to be 2.961 ± 0.003at 25°C.

Additional information

Biodegradation in water

Various predicted data for the target compound 3,5-Diaminobenzoic acid (CAS No. 535-87-5) and the study for its read across substance were reviewed for the biodegradation end point which are summarized as below:

 

Biodegradability of 3,5-Diaminobenzoic acid (CAS no. 535-87-5) is predicted using QSAR toolbox version 3.4 (2017). Test substance undergoes 33.25% degradation by CO2 evolution parameter in 28 days. Thus, based on percentage degradation, the test chemical 3,5-Diaminobenzoic acid was estimated to be not readily biodegradable in water.

 

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 3,5-Diaminobenzoic acid (CAS no. 535 -87 -5) 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 3,5-Diaminobenzoic acid is expected to be not readily biodegradable.

 

In a weight of evidence study of read across substance m-phenylenediamine (CAS no. 108 -45 -2) which is having a percentage similarity of 50-60% with the target chemical 3,5-Diaminobenzoic acid (J-CHECK, 2016), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance m-phenylenediamine (CAS no. 108 -45 -2). 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 read across substance was determined 2, 0 and 0% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, m-phenylenediamine is considered to be not readily biodegradable in nature.

 

Another weight of evidence study (HSDB, 2016) of biodegradation was conducted for 30 days for evaluating the percentage biodegradability of read across substance 3,5-Dichloroaniline (CAS no. 626 -43 -7) which is having a percentage similarity of 50-60% with the target chemical 3,5-Diaminobenzoic acid. The study was performed according to OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test). Activated sludge was used as a test inoculum. The percentage degradation of read across substance was determined to be 0% by BOD parameter in 30 days. Thus, based on percentage degradation, 3,5 -Dichloroaniline is considered to be not readily biodegradable in nature.

 

In an additional weight of evidence study (J-CHECK, 2016), biodegradation was conducted for 28 days for evaluating the percentage biodegradability of read across substance 4-Aminoazobenzene (CAS no. 60 -09 -3). 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 read across substance was determined 0% by BOD and HPLC parameter in 28 days. Thus, based on percentage degradation, 4 -Aminoazobenzene is considered to be not readily biodegradable in nature.

 

On the basis of above results for target and read across substance, it can be concluded that the test substance3,5-Diaminobenzoic acidcan be expected to be not readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 3,5-Diaminobenzoic acid (CAS No. 535 -87 -5). If released in to the environment, 35% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 3,5-Diaminobenzoic acid 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 moderate to low whereas the half-life period of 3,5-Diaminobenzoic acid 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 0.0835%), indicates that 3,5-Diaminobenzoic acid is not persistent in sediment.

Biodegradation in soil

The half-life period of 3,5-Diaminobenzoic acid (CAS No. 535 -87 -5) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 64.9% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 3,5-Diaminobenzoic acid in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 3,5-Diaminobenzoic acid, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

On the basis of available information, the test substance 3,5 -Diaminobenzoic acid can be considered to be not readily biodegradable in nature.

Bioaccumulation: aquatic / sediment:

Four studies including predicted data from validated models and experimental data from authorative database for Bioaccumulation endpoint for the target chemical 3,5 Diaminobenzoic acid (Cas no. 535-87-5) with relevant read across which is structurally similar were reviewed to summarize as follows:  

 

First study from EPI suite using BCFBAF Program (v3.01) model which indicate the Bioaccumulation factor (BCF) was predicted to be 3.162 L/kg wet-wt at 25 deg.C for target chemical 3,5 Diaminobenzoic acid.The predicted BCF value does not exceed the bioconcentration threshold of 2000.Thus it is concluded that 3,5 Diaminobenzoic acid is not expected to bio accumulate in the food chain.

Above predicted supported by another predicted database i.e PBT profiler which indicates the Bioaccumulation factor (BCF) was predicted to be 3.2 L/kg wet-wt at 25 deg.C. Based on the BCF concentration it is concluded that the test chemical 3,5 Diaminobenzoic acid is non bioaccumulative in nature as it does not exceed the BCF criteria of 2000.

And Scifinder database and Chemspider - ACD/PhysChem Suite suggest the Bioconcentration factor (BCF) for target chemical 3,5 Diaminobenzoic acid was predicted to be 1 at pH 1-10 and temperature 25 deg.C.

 All predicted results of target substance for BCF endpoint supported by Experimental study from authorative database (HSDB database; 2017) of read across chemical 4-Aminobenzoic acid (Cas no. 150-13-0) suggest that an estimated BCF of 3 was calculated in fish for 4-aminobenzoic acid, using a log Kow of 0.83 and a regression-derived equation.This BCF suggests the potential for bioconcentration in aquatic organisms is low.

 

All above results for bioaccumulation (BCF) for target and relevant read across results within the range 1-3.2 these resulted range of BCF concluded that the target chemical 3,5 Diaminobenzoic acid (Cas no. 535-87-5) is non Bioaccumulative in aquatic environment.

Adsorption / desorption:

Four studies which includes one experimental and remaining three supporting predicted values from validated models for adsorption endpoint of the target chemical 3,5 Diaminobenzoic acid (Cas no. 535-87-5) were reviewed to summarize as follows: 

 

First experimental study from UERL laboratory;2017 suggest the adsorption coefficient Koc in soil and in sewage sludge 3,5-diaminobenzoic acid(CAS No.535-87-5) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to functional similarity with the test substance and calibration graph was prepared. The reference substances were 4 -chloroaniline, 2 - nitrophenol, Nitrobenzene, 4-Nitrobenzamide, Benzamide having Koc value ranging from 1.239 to 2.47 The Log Koc value was found to be 2.961 ± 0.003at 25°C.

Above experimental study supported by prediction using EPI suite  KOCWIN (v2.00) program as Koc 10 L/kg(log Koc=1) by means of MCI method at 25 deg.C. This Koc value indicates that the substance 3,5 Diaminobenzoic acid has a Negligible sorption to soil and sediment and therefore have rapid migration potential to groundwater. 

Whereas another predicted database SciFinder, American Chemical Society (ACS); 2017 indicate the soil adsorption coefficient i.e Koc value of test substance 3,5 Diaminobenzoic acid was estimated to be 1 (dimensionless) at 1-2 and 6-10 pH, 1.46 at pH 3,3.91 at pH 4 and 2.97 at pH 5 and temperature 25 deg.C.

And from Chemspider - ACD/PhysChem Suite also support to both results i.e the soil adsorption coefficient i.e Koc value of test substance 3,5 Diaminobenzoic acid was estimated to be 2.56 at pH 5.5 and KOC=1.00 at pH 7.4 and temp.25 deg.C

 

Thus based on the above all available studies for target chemical 3,5 Diaminobenzoic acid (Cas no. 535-87-5) concluded that it is expected to have high to moderate mobility in soil and sediment compartment.