Benzyl isobutyrate

Endpoint summary

Description of key information

Biodegradation in water:

By applying weight of evidence approach and considering results of experimental data from structurally and functionally similar read across chemicals which are mentioned above the biodegradation of test chemical was determined to be >80% in 28 days. On the basis of percent degradation it is concluded that test chemical is readily biodegradable.

Biodegradation in water and sediments:

Estimation Programs Interface (EPI) Suite (2017) prediction model was run to predict the half-life in water and sediment for the test chemical. If released into the environment, 25% 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 15 days (360 hrs). The half-life (15 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 test chemical in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.361%), indicates that test chemical is not persistent in nature.

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 (EPI suite, 2017). If released into the environment, 72.3% 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 30 days (720 hrs). Based on this half-life value of test chemical, 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:

Biodegradation of test chemical was estimated by applying weight of evidence approach using experimental data from structurally and functionally similar read across chemicals. The studies are as mentioned below:

In first experimental study the Ready biodegradability of test chemical was determined by the Manometric Respirometry test according to the OECD Guidelines No. 301 F. Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage (City og Geneva, Aire) was used. The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000g for 10 min, discarding the supernatant and resuspending in the mineral medium) and kept aerobic until being used on the same day. The dry weight of suspended solids is determined by taking two 50 ml samples of the homogenized sludge, evaporating water on a steam bath, drying in an oven at 105-110°C for two hours and weighing the residue. In the study, a measured volume of the inoculated mineral medium, containing a known concentration of the test substance (100 mg/L) as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature (22±1°C) for upto 28 days. The consumption of oxygen is determined by measuring the quantity of oxygen (produced electrolytically) required to maintain constant the gas volume in the respirometer flask. The respirometer used during this study is a SAPROMAT D 12. Sodium benzoate was used as a reference substance for the study. Test chemical undergoes 89% biodegradation after 29 days (88% after 28 days) in the test conditions. Biodegradation starts on day 2 and reaches 76% at the end of the 10 day window (days 2 to 12). Thus, test chemical was considered to be readily biodegradable according to this test.

Another experimental study was reviewed from the authoritative database (J check) in this study the biodegradation screening test was conducted for 28 days (4 weeks) for evaluating the percentage biodegradability of the test substance. Concentration of inoculum i.e, sludge is 30 mg/l and initial test substance conc. used in the study was 100 mg/l. The percentage degradation of test substance was determined to be 95% by BOD, 98% by TOC and 100% by GC. Thus, the substance was considered to be readily biodegradable in water.

In last experimental study, 28-days Manometric respirometry test following the OECD guideline 301F was performed to determine the ready biodegradability of the test chemical. % Degradation was calculated using the values of BOD and ThOD for test item and reference item. The BOD28value of test chemical was observed to be 1.967 mgO2/mg. ThOD was calculated as 2.424 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was determined to be 81.15%.Based on the results, the test item, under the test conditions, was determined to be readily-Biodegradable at 20 ± 1°C over a period of 28 days.

By applying weight of evidence approach and considering results of experimental data from structurally and functionally similar read across chemicals which are mentioned above the biodegradation of test chemical was determined to be >80% in 28 days. On the basis of percent degradation it is concluded that test chemical is readily biodegradable.

Biodegradation in water:

Estimation Programs Interface (EPI) Suite (2017) prediction model was run to predict the half-life in water and sediment for the test chemical. If released into the environment, 25% 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 15 days (360 hrs). The half-life (15 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 test chemical in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.361%), indicates that test chemical is not persistent in nature.

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 (EPI suite, 2017). If released into the environment, 72.3% 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 30 days (720 hrs). Based on this half-life value of test chemical, 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.