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Biodegradation in water

Biodegradability of Pentyl formate (CAS no. 638 -49 -3) is predicted using OECD QSAR toolbox version 3.3 (2017) with logKow as the primary descriptor. Test substance undergoes 88.4% degradation by BOD in 28 days.Thus, based on percentage degradation, the test chemical Pentyl formate was estimated to be 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 Pentyl formate (CAS No. 638 -49 -3). If released in to the environment, 40.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Pentyl formate in water is estimated to be 8.66 days (208 hrs). The half-life (8.66 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 Pentyl formate in sediment is estimated to be 77.916 days (1870 hrs). Based on this half-life value, it indicates that Pentyl formate is not persistent in sediment.

Biodegradation in soil

The half-life period of Pentyl formate (CAS No. 638 -49 -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, 41.2% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of Pentyl formate in soil is estimated to be 17.33 days (416  hrs). Based on this half-life value of Pentyl formate, 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 Pentyl formate(CAS No. 638-49-3) and various supporting weight of evidence studies for its read across substance 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,Pentyl formate(CAS No. 638-49-3)was estimated.Test substance undergoes 88.4% degradation by BOD in 28 days.Thus, based on percentage degradation, the test chemical Pentyl formate was estimated to be readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compoundPentyl formate(CAS No. 638-49-3)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  Pentyl formate is expected to be readily biodegradable.

 

In a supporting weight of evidence study from peer reviewed journal (Kenneth S. Price et. al, 1974) for the read across chemical 1,3-dimethyl butyl acetate (CAS no. 108-84-9), biodegradation study was conducted for 20 days for evaluating the percentage biodegradability of read across substance1,3-dimethyl butyl acetate. Initial test substance conc. used in the study was 3, 7 and 10 mg/l, respectively. Domestic sewage, non-adapted was used as a test inoculum. The BOD bottles were half filled with aerated dilution water containing the specified minerals and buffer. Small aliquots of the test chemicals were added to these bottles from 0.1% stock solutions yielding conc. of 3, 7 and 10 mg/l. At least two of these concentrations were tested in duplicate. These concentrations gave a potential oxygen demand of 3 to 30 mg/l over the 20 days duration of test. Dissolved oxygen was monitored periodically in the individual bottles through the use of a commercial DO meter filled with an agitated probe. However, an oxygen meter that permitted correction for high salinity water was used for DO determinations where instrumental analysis was performed. The bottles were opened for sampling and DO measurements about five times during the course of the 20 day test. The percentage degradation of substance 1,3-dimethyl butyl acetate was determined to be 11, 22, 52 and 67% degradation in 5, 10, 15 and 20 days, respectively. Thus, based on percentage degradation,1,3-dimethyl butyl acetate was considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of read across substance sec-butyl acetate (CAS no. 105 -46 -4) (J-CHECK, 2017). 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 test substance formed acetic acid and sec-butanol in the test solution. The percentage degradation of substance sec-butyl acetate was determined to be 86, 94 and 100% by BOD, TOC removal and GC parameter in 14 days. Thus, based on percentage degradation, sec-butyl acetate is considered to be readily biodegradable in nature.

 

For another read across chemical 2-ethylhexyl acetate (CAS no. 103-09-3) from secondary source (OECD SIDS, 2010), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance 2 -ethylhexyl acetate. The study was performed according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) under aerobic conditions. Municipal wastewater activated sludge was used as a test inoculum for the study. The percentage degradation of substance 2 -ethylhexyl acetate was determined to be 16, 49, 66 and 70% by CO2 evolution parameter in 3, 7, 12 and 28 days, respectively. Thus, based on percentage degradation, 2 -ethylhexyl acetate is considered to be readily biodegradable in nature.

 

On the basis of above results for target chemicalPentyl formate(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (from peer reviewed journal, authoritative database J-CHECK and secondary source OECD SIDS), it can be concluded that the test substancePentyl formatecan be expected to be 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 Pentyl formate (CAS No. 638 -49 -3). If released in to the environment, 40.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Pentyl formate in water is estimated to be 8.66 days (208 hrs). The half-life (8.66 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 Pentyl formate in sediment is estimated to be 77.916 days (1870 hrs). Based on this half-life value, it indicates that Pentyl formate is not persistent in sediment.

Biodegradation in soil

The half-life period of Pentyl formate (CAS No. 638 -49 -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, 41.2% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of Pentyl formate in soil is estimated to be 17.33 days (416  hrs). Based on this half-life value of Pentyl formate, 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 Pentyl formate can be considered to be readily biodegradable in nature.