Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Biodegradation in water

Estimation Programs Interface Suite (2018) 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 test chemical is expected to be not readily biodegradable.

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 6.01% 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 persistent in 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 2% (i.e, reported as 1.22%), 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 (2018). If released into the environment, 92.8% 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 very persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to high.

Additional information

Biodegradation in water

Predicted data of the test chemical and various supporting studies for its functionally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done using Estimation Programs Interface Suite (2018), 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 test chemical is expected to be not readily biodegradable.

 

In a supporting weight study from authoritative database (J-CHECK, 2018) and secondary source (OECD SIDS, 2003), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I) under aerobic conditions at a temperature of 25°C, respectively. Activated sludge was used as a test inoculums for the study. Fresh sludge samples were collected from ten sites in Japan, such as municipal sewage-treatment plants, rivers, lakes and seas. The filtered supernatant of an activated sludge (cultivated sludge for 3 months) were mixed with an equal volume of the filtered supernatant of freshly collected ten-source mixture when used. And the activated sludge were cultivated for OECD TG 301C.Thirty mg of the test substance or aniline (reference substance) and 9 mg as MLSS (mixed liquor suspended solid) of activated sludge were added to 300 ml of test medium (OECD TG 301C).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. A volume of mixture was 300 ml. The test and reference solutions were cultivated in BOD meter together with the inoculum blank and abiotic control ones at 25 deg C for 28 days, during which the oxygen consumption was continuously measured. After termination of the test, the residual amount of the test substance and DOC (dissolved organic carbon) were determined individually with HPLC and TOC meter. And pH values of test solutions were measured. The biodegradability was calculated from the oxygen consumption and the residual amount. Aniline was used as a reference substance for the study. Test chemical was not detected at both water plus test substance and sludge plus test substance solutions after 28 days. In water plus test substance solutions, o-chlorobenzyl alcohol was detected by LC-MS after 28 days. Production rate of o-chlorobenzyl alcohol was 99% from the measurement by HPLC. Therefore, it is considered that test chemical hydrolyzed into o-chlorobenzyl alcohol. In sludge plus test substance solutions, o-chlorobenzyl alcohol, o-chlorobenzaldehyde and o-chlorobenzoic acid were detected respectively after 28 days. Mean production rates of o-chlorobenzyl alcohol, o-chlorobenzaldehyde and o-chlorobenzoic acid were 92, 2 and 3 % respectively. Consequently it is considered that test chemical is hydrolyzed and produces o-chlorobenzyl alcohol, and then the o-chlorobenzyl alcohol is slowly biodegradable to o-chlorobenzaldehyde and o-chlorobenzoic acid. Degradation pathway of test chemical is as follows: o-chlorobenzyl alcohol, o-chlorobenzaldehyde, o-chlorobenzoic acid. The percentage degradation of test chemical was determined to be 0 and 100% by BOD, TOC removal and HPLC parameter in 28 days. The test chemical formed o-Chlorobenzyl alcohol, o-Chlorobenzaldehyde and o-Chlorobenzoic acid in the test solution. Thus, based on percentage degradation (0% by BOD), test chemical is considered to be not readily biodegradable in nature.

 

Another biodegradation studywas conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to Zahn-Wellns test under aerobic conditions at a temperature of25°C, respectively. Sludge was used as a test inoculums for the study. Concentration of inoculum i.e, sludge used was 200 mg/l and initial test substance conc. used in the study was 160 mg/l, respectively. The percentage degradation of test chemical was determined to be 0% by after a period of 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

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

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 6.01% 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 persistent in 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 2% (i.e, reported as 1.22%), 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 (2018). If released into the environment, 92.8% 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 very 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 can be considered to be not readily biodegradable in nature.