2,5-xylidine

Endpoint summary

Description of key information

Biodegradation in water: screening tests

Percent biodegradation of test chemical was observed 0% by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

 

Bioaccumulation- aquatic or sediment

The Bioaccumulation factor (BCF) for the substance was determined to be at 1.5 L/kg for 1 mg/L and<= 3.8 L/kg for 0.1 mg/L

Adsorption / desorption

The Log Koc value was estimated to be 2.38. Thus based on the result it is concluded that the test substance has low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Additional information

Biodegradation in water: screening tests

Following different studies includes experimental and estimated study for the target chemical as well as read-across analogues which is extracted by using mechanistic approach and functionally and structurally similar to the target chemical to observe the biodegradation rate of test chemical in water.

First study (HSDB) was conducted to assess biodegradation rate of test chemical. The Biodegradation experiment was carried out to test biodegradability of test chemical by taking activated sludge as inoculums at 30mg/l concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC and HPLC .The initial concentration of test chemical was 100 mg/L. After 28 days of incubation percent biodegradation of test chemical was observed to be 0 % by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

First experimental study for the target chemical was further supported by study from publication (GILLES KLOPMAN. et al.)

In this study the biodegradability predicted by META was exactly the same as was observed experimentally. A computer program, META (MultiCASE, Cleveland, OH, USA) was designed and developed to help assess the susceptibility of test chemicals to biodegradation. Percent biodegradation of test chemical was predicted 1% by BOD, with the help of the MultiCASE methodology. Therefore it is concluded that test chemical is not readily biodegradable.

In next predicted data, Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound 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.

Similar study(P.pitter) conducted on the test chemical for biodegradation in 20 days at 200mg /l based on decrease in COD. The biological degradability of standard test substance by specimen was performed in a batch system. The tested substance is dissolved in a beaker in a biological medium in a concentration corresponding to 200mg/l COD. The tested substance is a sole source of organic carbon for the microbes of the inoculum. To the biological medium such amount of thickened adapted activated sludge is added the beaker is placed in a dark room with a roughly constant temperature of 20 ± 3 C on an electromagnetic stirrer. Activated sludge taken from a sewage plant is cultivated in a 1000ml volumetric cylinder. The mixture is aerated with pressure air. Biodegradation of test chemical in 20 days was 96.5 % at rate of 3 .6 mg COD g-1h-1based on COD in aerobic condition. So it concluded that the test compound is readily degradable.

 In the another study(J-check)of test chemical, the Biodegradation study was carried out to test biodegradability of test chemical by taking activated sludge as inoculums at 30mg/l concentration for 28 days. Biodegradation was analyzed by using three parameters that are BOD, TOC and HPLC .The initial concentration of test chemical was 100 mg/L. After 28 days of incubation percent biodegradation of test chemical was observed to be 0 % by BOD, TOC and HPLC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

The study from the peer reviewed journel indicates that the chemical is readily biodegradable in water as adapted inoculum were used, and thus degradation was observed. But the remaining studies supports the not readily biodegradable criteria. Thus, based on the overall values, it can be concluded that the chemical is not readily biodegradable in water.

Bioaccumulation- aquatic or sediment

Following study includes experimental study for the target chemical to observe the bioconcentration of test chemical.

 

Study (J-check) was conducted to determine the bioaccumulation of test chemical in Cyprinus carpio. After the exposure of test chemical with Cyprinus carpio, it was observed that the chemical is non-bioaccumulative as BCF was determined to be at 1.5 L/kg for 1 mg/L and <= 3.8 L/kg for 0.1 mg/L

Adsorption / desorption

Following different studies includes estimated study for the target chemical to observe the Adsorption of test chemical.

 

In first study (HSDB) the Koc of test chemical is estimated by using a measured log Kow of 1.83 and a regression-derived equation.The Koc is estimated as approximately 240 L/kg.The Log Koc value was determined to be 2.38. Thus based on the result it is concluded that the test substance has low sorption to soil and sediment and therefore has moderate migration potential to ground water.

 

The Soil Adsorption Coefficient i.e. Koc value of test chemical was estimated using EPI suite KOCWIN Program (v2.00) as 184.5L/kg (log Koc= 2.26) by means of MCI method at 25 deg. C.  This log Koc value indicates that test chemical has low sorption to soil and therefore test chemical has moderate migration potential to ground water.

 

Thus based on the above results it is concluded that the test substance has low sorption to soil and sediment and therefore has moderate migration potential to ground water.