Geranyl propionate

Endpoint summary

Description of key information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model was used to predict the hydrolysis half-life of test compound (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8). The estimated half-life of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 274.146 days and 27.415 days at pH 7 and 8 (at 25 deg C) respectively, indicating that it is not hydrolysable.

Biodegradation in water

Biodegradability of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS no. 105 -90 -8) is predicted using QSAR toolbox version 3.4 (2017) with logKow as the primary descriptor. Test substance undergoes 90% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8). If released in to the environment, 18.8% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 0.637%), indicates that (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoateis not persistent in sediment.

Biodegradation in soil

The half-life period of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105 -90 -8) 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, 80.5% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate, 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.

Bioaccumulation: aquatic / sediment

BCFBAF model (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate  (CAS No. 105 -90 -8). The bioconcentration factor (BCF) of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 878.8 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate is not expected to bioaccumulate in the food chain.

Adsorption / desorption

KOCWIN model (v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8). The soil adsorption coefficient i.e Koc value of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 959.5 L/kg (log Koc=2.9820)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

Additional information

Hydrolysis

Predicted data for the target chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105-90-8) and supporting weight of evidence study from authoritative database for its read across substance were reviewed for the hydrolysis end point which are summarized as below:

 

In aprediction using the HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model, the hydrolysis half-life of test compound (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8) was estimated. The estimated half-life of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 274.146 days and 27.415 days at pH 7 and 8 (at 25 deg C) respectively, indicating that it is not hydrolysable.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate (CAS no. 105-87-3), the half-life and base catalyzed second order hydrolysis rate constant was determined using a structure estimation method of the read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate. The second order hydrolysis rate constant of (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate was determined to be 0.35L/mol-sec with a corresponding half-lives of 231 and 23 days at pH 7 and 8, respectively. Based on the half-life values, it is concluded that the chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate is not hydrolysable.

 

On the basis of the above results for target chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(fromEPI Suite, 2017) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that the test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate is not hydrolysable.

Biodegradation in water

Various predicted data for the target compound (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105-90-8) 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 3.4 with logKow as the primary descriptor, percentage biodegradability of test chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(CAS No. 105-90-8) was estimated.Test substance undergoes 90% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 compound(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(CAS No. 105-90-8) 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 (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate is expected to be readily biodegradable.

 

In a supporting weight of evidence study from peer reviewed journal (N. Scholz et.al; 1997) for the read across chemical 1,2-Benzenedicarboxylic acid, dibutyl ester (CAS no. 84-74-2), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance 1,2-Benzenedicarboxylic acid, dibutyl ester. The study was performed according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) (Modified Sturm test).Sewage sludge was used as a test inoculum during the study. As biological inoculum a sludge sample from a nearby sewage treatment plant, treating household sewage only, was employed. After collecting the sludge from the plant, it was washed thoroughly with an artificial mineral medium as described in the guidelines. The sludge was thoroughly mixed with the final washing solution and an appropriate amount was then used as inoculum. Concentration of inoculum i.e, sludge used was 29 mg/l suspended solids, which corresponds to roughly60 x 104 cfu / ml (colony forming units)and initial test substance conc. used in the study was 15 mg/l, respectively. Special care has been taken to introduce the test substance into the Sturm test vessels. The phthalates (test chemical) have been dosed into precleaned Eppendorf vials at an amount corresponding to 15 mg organic carbon by direct weighing. One day before the start of the test, the vessels are filled with the mineral medium and the prewashed inoculum, sealed airtight and flushed with CO2 free air. The Eppendorf vials are placed within the Sturm test bottles by opening a small stop cock. The whole system is subsequently closed airtight again and flushed with CO2 free air.In the study, the test substance was incubated in a mineral medium and inoculated with a minor amount of sewage sludge. No further carbon source is offered to the organisms during the study. The system is sealed air tight and flushed with CO, free air. The amount of carbon dioxide generated during the 28 days exposure is then determined.CO2 evolution has been measured with a cabon analyzer TOC 500, by injection of 10-20μl of a sample of the carbon trap content. The evolved carbon dioxide was put into relation to the carbon content of the sample introduced, and the amount of degradation was calculated over the sampling time. The test stopped after 28 days. The total content of the Sturm test vessel is then acidified to drive out remaining CO2 traces from the vessel into the NaOH trap. CO2 evolution has been measured with a cabon analyzer TOC 500, by injection of 10-20μl of a sample of the carbon trap content. A second control without any organic carbon was set up to compensate for any CO2 release during sample introduction and the self aspiration of the inoculum. Quite a rapid onset of the CO2 evolution can be observed, and, starting with the 10 % value, the minimum biodegradation of test chemical1,2-Benzenedicarboxylic acid, dibutyl ester with percentage degradation of 60 % is easily accomplished within the next 10 subsequent days. Thus, the 10 day window criteria has been reached. The percentage degradation of substance 1,2-Benzenedicarboxylic acid, dibutyl ester was determined to be79 to 85% by CO2 evolution parameter in 28 days. Thus, based on percentage degradation,1,2-Benzenedicarboxylic acid, dibutyl ester is considered to be readily biodegradable in nature.

 

For the read across chemical 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester (CAS no. 84-66-2), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester by using a settled domestic wastewater as microbial inoculum (Henry H. Tabak et. al; 1981). Settled domestic wastewater was used as a microbial inoculum. Conc. of test substance used for the study are 5 and 10 mg/l, respectively. Biochemical oxygen demand (BOD) dilution water containing 5mg of yeast extract per litre, was used as the synthetic medium. Stock solution of test substance was prepared in absolute ethanol. Stock solutions were prepared as 10% solutions. Erlenmeyer flasks was used as a test vessel. Test also involve the incorporation of both the medium-inoculum control to serve as blank control for determining base lines for both GC analysis and for DOC and TOC as well as the medium-substrate control series for determination of possible autooxidation, photolysis, and volatilization. Homogenous suspension of 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester (Diethyl phthalate) in the synthetic medium were prepared by adding appropriate amounts of test compound to prechilled synthetic medium in a heavy-duty blender and blending the medium for 2 mins. The blended substrate containing media were then introduced into Erlenmeyer flasks and inoculated with prechilled yeast extract and settled domestic wastewater inoculum. The flasks containing the medium with the test compound and inoculum, as well as the medium-wastewater and medium-test compound control flasks, were incubated in a constant temperature room at 25°C in darkness. Flasks were shaken on a daily basis during the incubation period. The culture samples were extracted three times with 20 ml portions of methylene chloride at neutral pH, except for the control phenol culture samples which were acidified before extraction. The extraction, evaporation, and sparging procedure was that used for phenolic compounds. Duplicate samples at the beginning of each incubation period and triplicate samples at the end of the 7-day incubation for the original and each subculture were subjected to GC, TOC and DOC analysis. The percentage degradation of test substance1,2-Benzenedicarboxylic acid, 1,2-diethyl ester was determined to be 100% by GC, TOC or DOC analysis after 7 days. Based on the percentage degradation, the test chemical 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester was considered to be readily biodegradable in nature.

 

Another biodegradation study from peer reviewed journal (RICHARD H. SUGATT et. al; 1984) was conducted according to CO2 evolution shake flask test for 28 days for evaluating the percentage biodegradability of the same read across substance 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester (CAS no. 84-66-2).The study was performed under aerobic conditions at a temperature of22 ± 2°C and a pH7 ± 0.2, respectively. Initial test substance conc. used in the study was 20 mg/l, respectively. Mixture of soil and sewage microorganisms was used as a test inoculum for the study. The inoculum was prepared from soil, sewage microorganisms, and test chemical1,2-Benzenedicarboxylic acid, 1,2-diethyl ester (Diethyl phthalate)in a 2-week acclimation period before the test initiation. For test chemical, 1 liter of acclimation medium in a 2-liter Erlenmeyer flask was inoculated with a1,2-Benzenedicarboxylic acid, 1,2-diethyl ester concentration equivalent to 4 mg of carbon at the start of acclimation. The acclimation flasks were sealed and incubated in the dark on a Gyrotory shaker at 120 rpm and 22 ± 2°C. An additional test compound equivalent to 8 mg of carbon was added on day 7 and again on day 11 during the 14-day acclimation period. At the end of the acclimation period, the contents of all of the acclimation flasks in a set were pooled and filtered through glass wool to provide a common inoculum for the primary and ultimate biodegradation tests.

A measured weight (nominal 20 mg) of test compound (1,2-Benzenedicarboxylic acid, 1,2-diethyl esteror glucose) on a preweighed glass slide was added to the appropriate flasks. Then, 100 ml of the pooled acclimation inoculum was added to the seven flasks for each test chemical in a set and to the glucose and blank control flasks. The blank control flask received neither1,2-Benzenedicarboxylic acid, 1,2-diethyl esternor glucose. After the addition of the test compound, the pH was measured and was 7.0 + 0.2 without adjustment. The contents of two of the Erlenmeyer flasks for test chemical1,2-Benzenedicarboxylic acid, 1,2-diethyl ester were immediately extracted for specific chemical analysis at time zero to determine the percent recovery. The remaining flasks were sparged with 70% oxygen in nitrogen (CO2 free) for 5 min to remove CO2 and sealed, and 10 ml of 0.2 N Ba(OH)2 base was added to the central suspended reservoir of the CO2 evolution flasks by injection through the septum seal. The flasks were incubated in the dark on a Gyrotory shaker at 120 rpm and 22 ± 2°C.Differences in the CO2 evolution between control flasks containing no test chemical and flasks containing1,2-Benzenedicarboxylic acid, 1,2-diethyl ester were used to determine the extent and rate of ultimate biodegradation. At the beginning, middle, and end of the test, the entire contents of replicate flasks were extracted with hexane, and the concentrated extract was analyzed by gas chromatography with a flame ionization detector to determine the amount of 1,2-Benzenedicarboxylic acid, 1,2-diethyl ester remaining (primary biodegradation).The percentage degradation of test substance1,2-Benzenedicarboxylic acid, 1,2-diethyl ester was determined to be>99% and 95% by test material analysis and CO2 evolution parameter in 28 days. Thus, based on percentage degradation,1,2-Benzenedicarboxylic acid, 1,2-diethyl ester is considered to be readily biodegradable in nature.

 

In a supporting weight of evidence study from authoritative database (J-CHECK, 2017 and EnviChem, 2014) for the read across chemical 3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoate (CAS no. 77-68-9),biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance 3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoate. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). 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 read across substance 3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoatewas determined to be96, 94 and 100% by BOD, TOC removal and GC parameter in 28 days. Thus, based on percentage degradation, 3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoate is considered to be readily biodegradable in nature.

 

On the basis of above results for target chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (from peer reviewed journals and authoritative database J-CHECK & EnviChem), it can be concluded that the test substance(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate can 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 (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8). If released in to the environment, 18.8% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate 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 0.637%), indicates that (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoateis not persistent in sediment.

Biodegradation in soil

The half-life period of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105 -90 -8) 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, 80.5% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate, 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 (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate can be considered to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105-90-8) and supporting weight of evidence study for its read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In aprediction done using theBCFBAF Program(v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate  (CAS No. 105 -90 -8). The bioconcentration factor (BCF) of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 878.8 L/kg whole body w.w (at 25 deg C).

 

In an another prediction done by using Bio-concentration Factor (v12.1.0.50374) moduleACD (Advanced Chemistry Development)/I-Lab predictive module, 2017), theBCF over the entire pH scale (pH 1 -14) of the test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS no. 105 -90 -8) was estimated to be 1963.

 

Bioconcentration Factor (BCF) of test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated using Chemspider database(ChemSpider, 2017). The bioconcentration factor of test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 903.14 at both pH 5.5 and 7.4, respectively.

 

Another predicted data was estimated usingSciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate  (CAS No. 105 -90 -8). The bioconcentration factor (BCF) of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 1330 (at 25 deg C).

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the bioaccumulation i.e BCF for test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 46.1 dimensionless . The predicted BCF result based on the 5 OECD principles. Thus based on the result it is concluded that the test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate is non-bioaccumulative in nature.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate (CAS no. 105-87-3), bioaccumulation experiment in fish was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate. The bioaccumulation factor (BCF) value was calculated using a log Kow of 4.04 and a regression equation. The estimated BCF (bioaccumulation factor) value of (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl acetate in fish was determined to be 260 dimensionless.

 

On the basis of above results for target chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(from EPI suite, ACD labs,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,  2017) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that the BCF value of test substance(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoateranges from 46.1 – 1963 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoateis not expected to bioaccumulate in the food chain.

Adsorption / desorption

Various predicted data for the target compound (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105-90-8) and supporting weight of evidence study for its read across substance were reviewed for the adsorption end point which are summarized as below:

 

In aprediction done using theKOCWIN Program(v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl propanoate (CAS No. 105 -90 -8). The soil adsorption coefficient i.e Koc value of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 959.5 L/kg (log Koc=2.9820)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

 

The Soil Adsorption Coefficient i.e Koc value of test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS no. 105 -90 -8) was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 7919 (log Koc = 3.9 ± 1.0) at pH range 1-14 respectively(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017). This Koc value indicates that the test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a strong sorption to soil and therefore have negligible to slow migration potential to groundwater.

 

In an another prediction done by using ChemSpider Database (2017),the Soil Adsorption Coefficient i.e Koc value of test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS no. 105 -90 -8) was estimated. The adsorption coefficient (Koc) value of test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 4542.88 (Log Koc = 3.657) at both pH 5.5 and 7.4, respectively. This Koc value indicates that the test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a strong sorption to soil and therefore have negligible to slow migration potential to groundwater.

 

Additional soil adsorption coefficient i.e Koc value of test chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate (CAS No. 105 -90 -8)was estimated using the SciFinder database (American Chemical Society (ACS), 2017).The soil adsorption coefficient i.e Koc value of (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 5990 (log Koc = 3.777) (at 25 deg C). This Koc value indicates that the test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a strong sorption to soil and therefore have negligible to slow migration potential to groundwater.

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application) V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the adsorption coefficient i.e KOC for test substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate was estimated to be 878 L/kg (log Koc = 2.943).The predicted KOC result based on the 5 OECD principles. This Koc value indicates that the substance (2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate (CAS no. 105-87-3),adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of read across chemical (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate. The adsorption coefficient (Koc) value was calculated using a measured logKow of 4.04 and a regression derived equation. The adsorption coefficient (Koc) value of test substance (2E)-3,7 -dimethylocta-2,6 -dien-1 -yl acetate was estimated to be 3700 (Log Koc = 3.568). This Koc value indicates that the substance (2E)-3,7-dimethylocta-2,6-dien-1-yl acetate has a strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.

 

On the basis of above overall results for target chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoate(from EPI suite, ACD labs,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,2017) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that the Koc value of test substance(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoateranges from 878–7919indicating that the test chemical(2E)-3,7-dimethylocta-2,6-dien-1-yl propanoatehas a moderate to strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.