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Biodegradation in water

Biodegradability of 2-Ethoxy-1-naphthoyl Chloride (CAS no. 55150 -29 -3) is predicted using QSAR toolbox version 3.3 (2017) with logKow as the primary descriptor. Test substance undergoes 17.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-Ethoxy-1-naphthoyl Chloride 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 2-Ethoxy-1-naphthoyl Chloride (CAS No. 55150 -29 -3). If released in to the environment, 21% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 2-Ethoxy-1-naphthoyl Chloride 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 2-Ethoxy-1-naphthoyl Chloride 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 0.272%), indicates that 2-Ethoxy-1-naphthoyl Chloride is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 2-Ethoxy-1-naphthoyl Chloride (CAS No. 55150 -29 -3) 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, 78.5% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 2-Ethoxy-1-naphthoyl Chloride in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 2-Ethoxy-1-naphthoyl Chloride, 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.

Additional information

Biodegradation in water

Various predicted data for the target compound 2-Ethoxy-1-naphthoyl Chloride (CAS No. 55150-29-3) and supporting weight of evidence studies for its closest read across substance with logKow as the primary descriptor were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical 2-Ethoxy-1-naphthoyl Chloride(CAS No. 55150-29-3) was estimated.Test substance undergoes 17.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-Ethoxy-1-naphthoyl Chloride was estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound 5-methyl-3-phenyl-1,2-oxazole-4-carbonyl chloride(CAS No. 16883-16-2) in the presence of mixed populations of environmental microorganisms was estimated.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 2-Ethoxy-1-naphthoyl Chloride is expected to be not readily biodegradable.

 

In a supporting weight of evidence study from authoritative database (J-CHECK, 2017) for the read across chemical (2E)-N-ethyl-N-(2-methylphenyl)but-2-enamide (CAS no. 483-63-6),biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance (2E)-N-ethyl-N-(2-methylphenyl)but-2-enamide. Activated sludge was used as a test inoculums for the study. 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 substance (2E)-N-ethyl-N-(2-methylphenyl)but-2-enamide was determined to be 2 and 0% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, (2E)-N-ethyl-N-(2-methylphenyl)but-2-enamide is considered to be not readily biodegradable in nature.

 

For the read across chemical (3E)-4-phenylbut-3-en-2-one (CAS no. 122-57-6), biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of read across substance (3E)-4-phenylbut-3-en-2-one (J-CHECK, 2017). Activated sludge was used as a test inoculums for the study. 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 substance (3E)-4-phenylbut-3-en-2-onewas determined to be 4, < 0 and 1% by BOD, O2 consumption, TOC removal, test mat. analysis and GC parameter in 14 days. Thus, based on percentage degradation, (3E)-4-phenylbut-3-en-2-one is considered to be not readily biodegradable in nature.

 

In a supporting weight of evidence study from secondary source (HPVIS, 2017) for the read across chemical 1,2-aminoazophenylene (CAS no. 95-14-7), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance 1,2-aminoazophenylene. The study was performed according to OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test) under aerobic conditions. Predominantly domestic sewage (adapted) was used as a test inoculums for the study. Initial test substance conc. used in the study were2.4, 8, 24 and 80 mg/l, respectively. The percentage degradation of substance 1,2-aminoazophenylene was determined to be 0 % by BOD parameter in 28 days. Thus, based on percentage degradation,1,2-aminoazophenylene is considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for 20 days for evaluating the percentage biodegradability of the same read across substance 1,2-aminoazophenylene (CAS no. 95-14-7) (HPVIS, 2017). The study was performed according to other guideline River die-away test under aerobic conditions. Aniline was used as a reference substance for the study. It undergoes 100% degradation in 14 days. The percentage degradation of substance 1,2 -aminoazophenylene was determined to be 0% by Test mat. analysis (%degradation) parameter in 20 days. Thus, based on percentage degradation, 1,2 -aminoazophenylene is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical2-Ethoxy-1-naphthoyl Chloride(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (from authoritative database J-CHECK and secondary source HPVIS), it can be concluded that the test substance2-Ethoxy-1-naphthoyl Chloridecan 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 2-Ethoxy-1-naphthoyl Chloride (CAS No. 55150 -29 -3). If released in to the environment, 21% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 2-Ethoxy-1-naphthoyl Chloride 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 2-Ethoxy-1-naphthoyl Chloride 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 0.272%), indicates that 2-Ethoxy-1-naphthoyl Chloride is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 2-Ethoxy-1-naphthoyl Chloride (CAS No. 55150 -29 -3) 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, 78.5% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 2-Ethoxy-1-naphthoyl Chloride in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 2-Ethoxy-1-naphthoyl Chloride, 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 2-Ethoxy-1-naphthoyl Chloride can be considered to be not readily biodegradable in nature.