3-phenylpropyl acetate

Endpoint summary

Additional information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI) Suite (2016) prediction model was used to predict the hydrolysis half-life of test compound 3-Phenylpropyl acetate(CAS No. 122 -72 -5). The estimated half-life of 3-Phenylpropyl acetate was evaluated to be 2.142 years and 78.232 days at pH 7.0 and 8.0 (at 25ᵒC) respectively, indicating that it is not hydrolysable.

Biodegradation in water

Various predicted data for the test compound 3-Phenylpropyl acetate (CAS No. 122-72-5) and for its read across substance were reviewed for the biodegradation end point which are summarized as below:

Biodegradability of 3-Phenylpropyl acetate is predicted using QSAR toolbox version 3.4 (SSS QSAR Prediction Model, 2016). Test substance undergoes 81.11% degradation by CO2 evolution in 28 days. Thus, based on percentage degradation, the test chemical 3-Phenylpropyl acetate was estimated to be readily biodegradable in water.

Estimation Programs Interface Suite (EPI suite, 2016) was run to predict the biodegradation potential of the test compound 3-Phenylpropyl acetate (CAS no. 122 -72 -5) 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 3-Phenylpropyl acetate is expected to be readily biodegradable.

28-days Manometric respirometry test following the OECD guideline 301F to determine oxygen consumption and thereby % degradation during the test period was conducted for the read across substance Methyl Phenylacetate (CAS No. 101-41-7) (UERL study report, Sustainability Support Services (Europe) AB, Report no. RBD-002/101-41-7/2015, 2015). The test system included control, read across substance and reference substance. The concentration of read across and reference substance (sodium acetate) chosen for the study were 100 mg/l & 100 mg/l respectively while that of inoculum was 10 ml/l. ThOD (Theoretical oxygen demand) of read across and reference substance was determined by calculation. % Degradation was calculated using the values of BOD and ThOD for Methyl Phenylacetate and reference substance. The BOD28value of Methyl Phenylacetate (CAS No. 101-41-7) was observed to be 1.469 mgO2/mg. ThOD was calculated as 2.237 mgO2/mg. Accordingly, the % degradation of the read across substance after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was determined to be 65.66 % . Based on the results, the read across substance Methyl Phenylacetate, under the test conditions, was determined to be readily biodegradable at 20 ± 1°C over a period of 28 days.

 

The Ready biodegradability of benzyl propionate was determined by the Manometric Respirometry test according to the OECD Guidelines No. 301 F (Givaudan Roure SA, Dr. J. Rudio, Report no. 99-E78, 1999). 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 read across substance benzyl propionate (CAS no. 122-63-4) (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. Benzyl propionate 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, benzyl propionate was considered to be readily biodegradable according to this test.

 

Biodegradation study was conducted for 28 days (4 weeks) for evaluating the percentage biodegradability of the read across substance Benzyl acetate (CAS no. 140-11-4) using the OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) and Other guideline: New Biodegradability Test developed (R R Birch and R J Fletcher; 1991). The Sturm method was used in conjunction to validate the results of the new method. The test was performed under aerobic conditions using activated sludge as an inoculum with conc. of 30 mg/l and initial test substance conc. is 10 mg/l (ranges from 2 – 10 mg/l). The read across substance in a dilute mineral salts solution is incubated in sealed vessels with appropriate micro-organisms for a period of up to 28 days. Controls containing the 0.5 to 10% inoculum concentration, but no read across compound Benzyl acetate are also prepared. A vessel is removed from the shaker as required, a sample of the headspace gas withdrawn using a gas syringe and the concentration of carbon dioxide determined. The seal is then broken and the concentration of dissolved inorganic carbon (DIC) in the solution is measured immediately, Similar determinations are made for a control vessel which does not contain the Benzyl acetate. The difference in the total inorganic carbon found in the test and control vessels allows the quantity of carbon dioxide produced from the read across chemical to be ascertained.

The determination of carbon dioxide in both gaseous and aqueous samples was performed using a modified Ionics 555 TC-T°C Analyser. Carbon dioxide is released from aqueous samples of carbonate/bicarbonate by direct injection using a 0-200 µl Hamilton constant rate syringe onto an inert support loaded with phosphoric acid. The temperature in the reaction chamber is controlled at 150°C and pure nitrogen is used as the carrier gas. The detection system is a high sensitivity non-dispersive infra-red analyser. Gaseous samples are injected using a good quality gastight syringe. A preliminary study was conducted using 2 mg/L of read across substance conc. The percentage biodegradation of Benzyl acetate was found to be 100.9% with standard deviation of 2.5 and 95% confidence interval of 96.9 – 104.9. Thus, the substance benzyl acetate was determined to be readily biodegradable.

 

Biodegradation screening test was conducted for 28 days (4 weeks) for evaluating the percentage biodegradability of the read across substance Benzyl acetate (CAS no. 140-11-4) (J-CHECK, 2016) . Concentration of inoculum i.e, sludge is 30 mg/l and initial substance conc. used in the study was 100 mg/l. The percentage degradation of read across substance was determined to be 95% by BOD, 98% by TOC and 100% by GC. Thus, the substance benzyl acetate was considered to be readily biodegradable in water.

 

Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of the read across substance benzyl acetate (CAS no. 140-11-4) (Data bank of Environmental Properties of Chemicals (EnviChem), 2014). Concentration of inoculum i.e, sludge used was 30 mg/l and initial substance conc. used in the study was100 mg/l. The percentage degradation of read across substance was determined to be 92-96% in 28 days. Thus, the substance benzyl acetate was determined to be readily biodegradable.

 

On the basis of above results for target and read across substance, it can be concluded that the test substance 3-Phenylpropyl acetate can be expected to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI) Suite (2016) prediction model was run to predict the half-life in water and sediment for the test compound 3-Phenylpropyl acetate (CAS No. 122 -72 -5). If released in to the environment, 25% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 3-Phenylpropyl acetate 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 3-Phenylpropyl acetate 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 0.393%), indicates that 3-Phenylpropyl acetate is not persistent in nature.

Biodegradation in soil

The half-life period of 3-Phenylpropyl acetate (CAS No. 122 -72 -5) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2016). If released into the environment, 72.6% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 3-Phenylpropyl acetate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of 3-Phenylpropyl acetate, 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 substance3 -Phenylpropyl acetatecan be considered to be readilybiodegradable in nature.

Adsorption / desorption:

Predicted and experimental data of adsorption endpoint for the target chemical 3-phenylpropyl acetate (Cas no. 122-72-5) and its read across chemical were reviewed to summarize as follows:  

 

From predicted model EPI suite 2016 indicate that the soil adsorption coefficient (Koc) value of chemical 3-phenylpropyl acetate is estimated to be 380.7 L/kg (log KOC = 2.5805) by means of MCI method at 25 deg.C, This Koc value indicates that the substance 3-phenylpropyl acetate has a Moderate sorption to soil and sediment and therefore have slow migration potential to groundwater. 

Whereas from chemspider predicted database the soil adsorption coefficient i.e Koc value of test substance 3-phenylpropyl acetate was estimated to be 768.68 L/Kg i.e Log Koc= 2.88574 at pH 5.5 and 7.4. This Koc value indicates that the substance 3-phenylpropyl acetate has a Moderate sorption to soil and sediment and therefore has slow migration potential to groundwater. 

Experimental study for read across substance Benzyl butyrate(CAS No. 103-37-7) indicate the adsorption coefficient Koc in soil and in sewage sludge was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were4-chloroaniline, 4-methylaniline, N methylaniline, 2-Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having Koc value ranging from 1.239 to 4.09.The Log Koc value was found tobe3.323± 0.0005at 25°C.( UNIQUE ECOTOX RESEARCH LABORATORY; 2015)

From HSDB database; 2016 the read across chemical benzyl acetate (Cas no. 140-11-4) indicate the adsorption coefficient (Koc) of substance benzyl acetate was found to be 180 using a log Kow of 1.96 and a regression-derived equation. This Koc value suggests that benzyl acetate is expected to have moderate mobility in soil.

Thus based on the above all studies it is concluded that the test substance 3-phenylpropyl acetate (Cas no. 122-72-5) is expected to have slow to moderate mobility in soil/sediment.