Phenethyl butyrate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from computational model developed by USEPA

Justification for type of information:

Data is from computational model developed by USEPA

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

The Biodegradation Probability Program (BIOWIN) estimates the probability for the rapid aerobic biodegradation of an organic chemical in the presence of mixed populations of environmental microorganisms .The model is part of the EpiSuite program of the US-EPA. Estimations are made with BIOWIN version 4.10Estimates are based upon fragment constants that were developed using multiple linear and non-linear regression analyses. Experimental biodegradation data for the multiple linear and non-linear regressions were obtained from Syracuse Research Corporation's (SRC) data base of evaluated biodegradation data (Howard et. al., 1987). This version (v4.10) designates the models as follows (see also Boethling et al. 2003):
Biowin1 = linear probability model
Biowin2 = nonlinear probability model
Biowin3 = expert survey ultimate biodegradation model
Biowin4 = expert survey primary biodegradation model
Biowin5 = MITI linear model
Biowin6 = MITI nonlinear model
Biowin7 = anaerobic biodegradation model

GLP compliance:

not specified

Oxygen conditions:

other: aerobic (Biowin 1-6) and anaerobic (Biowin 7)

Inoculum or test system:

other: mixed populations of environmental microorganisms

Duration of test (contact time):

2.862 wk

Details on study design:

Using the computer tool BIOWIN v4.10 by US-EPA (EPIWIN) the aerobic as well as the anaerobic biodegradability of the test material can be estimated. The follwoing seven different models are used by the tool: Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI LInear Model, MITI Non-Linear Model and Anaerobic Model (calles Biowin 1-7, respectively). Due to this results the overall prediction of readily biodegradability is done for the desired chemical.

Parameter:

other: Half-life

Value:

50

Sampling time:

2.862 wk

Remarks on result:

other: Other details not known

Details on results:

Biowin1 (Linear Model Prediction) : 1.0130: Biodegrades Fast
Biowin2 (Non-Linear Model Prediction): 0.9988: Biodegrades Fast
Biowin3 (Ultimate Biodegradation Timeframe): 2.8617: Weeks
Biowin4 (Primary Biodegradation Timeframe): 3.7357: Days-Weeks
Biowin5 (MITI Linear Model Prediction) : 0.6180: Biodegrades Fast
Biowin6 (MITI Non-Linear Model Prediction): 0.7695: Biodegrades Fast
Biowin7 (Anaerobic Model Prediction): 0.6256: Biodegrades Fast
Ready Biodegradability Prediction: YES

BIOWIN (v4.10) Program Results:

==============================

SMILES : O=C(OCCc(cccc1)c1)CCC

CHEM : Butanoic acid, 2-phenylethyl ester

MOL FOR: C12 H16 O2

MOL WT : 192.26

--------------------------- BIOWIN v4.10 Results ----------------------------

Biowin1 (Linear Model Prediction) : Biodegrades Fast

Biowin2 (Non-Linear Model Prediction): Biodegrades Fast

Biowin3 (Ultimate Biodegradation Timeframe): Weeks

Biowin4 (Primary Biodegradation Timeframe): Days-Weeks

Biowin5 (MITI Linear Model Prediction) : Biodegrades Fast

Biowin6 (MITI Non-Linear Model Prediction): Biodegrades Fast

Biowin7 (Anaerobic Model Prediction): Biodegrades Fast

Ready Biodegradability Prediction: YES

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin1 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 0.1742 | 0.1742

Frag | 1 | Alkyl substituent on aromatic ring | 0.0547 | 0.0547

Frag | 1 | Unsubstituted phenyl group (C6H5-) | 0.1281 | 0.1281

MolWt| * | Molecular Weight Parameter | | -0.0915

Const| * | Equation Constant | | 0.7475

============+============================================+=========+=========

RESULT | Biowin1 (Linear Biodeg Probability) | | 1.0130

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin2 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 4.0795 | 4.0795

Frag | 1 | Alkyl substituent on aromatic ring | 0.5771 | 0.5771

Frag | 1 | Unsubstituted phenyl group (C6H5-) | 1.7991 | 1.7991

MolWt| * | Molecular Weight Parameter | | -2.7301

============+============================================+=========+=========

RESULT | Biowin2 (Non-Linear Biodeg Probability) | | 0.9988

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Biodegrades Fast

A Probability Less Than 0.5 indicates --> Does NOT Biodegrade Fast

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin3 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 0.1402 | 0.1402

Frag | 1 | Alkyl substituent on aromatic ring | -0.0749 | -0.0749

Frag | 1 | Unsubstituted phenyl group (C6H5-) | 0.0220 | 0.0220

MolWt| * | Molecular Weight Parameter | | -0.4249

Const| * | Equation Constant | | 3.1992

============+============================================+=========+=========

RESULT | Biowin3 (Survey Model - Ultimate Biodeg) | | 2.8617

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin4 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 0.2290 | 0.2290

Frag | 1 | Alkyl substituent on aromatic ring | -0.0685 | -0.0685

Frag | 1 | Unsubstituted phenyl group (C6H5-) | 0.0049 | 0.0049

MolWt| * | Molecular Weight Parameter | | -0.2774

Const| * | Equation Constant | | 3.8477

============+============================================+=========+=========

RESULT | Biowin4 (Survey Model - Primary Biodeg) | | 3.7357

============+============================================+=========+=========

Result Classification: 5.00 -> hours 4.00 -> days 3.00 -> weeks

(Primary & Ultimate) 2.00 -> months 1.00 -> longer

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin5 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 0.3437 | 0.3437

Frag | 1 | Aromatic-CH2 | -0.0557 | -0.0557

Frag | 5 | Aromatic-H | 0.0082 | 0.0411

Frag | 1 | Methyl [-CH3] | 0.0004 | 0.0004

Frag | 3 | -CH2- [linear] | 0.0494 | 0.1482

MolWt| * | Molecular Weight Parameter | | -0.5720

Const| * | Equation Constant | | 0.7121

============+============================================+=========+=========

RESULT | Biowin5 (MITI Linear Biodeg Probability) | | 0.6180

============+============================================+=========+=========

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin6 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 2.4462 | 2.4462

Frag | 1 | Aromatic-CH2 | -0.1246 | -0.1246

Frag | 5 | Aromatic-H | 0.1201 | 0.6007

Frag | 1 | Methyl [-CH3] | 0.0194 | 0.0194

Frag | 3 | -CH2- [linear] | 0.4295 | 1.2885

MolWt| * | Molecular Weight Parameter | | -5.5503

============+============================================+=========+=========

RESULT |Biowin6 (MITI Non-Linear Biodeg Probability)| | 0.7695

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Readily Degradable

A Probability Less Than 0.5 indicates --> NOT Readily Degradable

------+-----+--------------------------------------------+---------+---------

TYPE | NUM | Biowin7 FRAGMENT DESCRIPTION | COEFF | VALUE

------+-----+--------------------------------------------+---------+---------

Frag | 1 | Ester [-C(=O)-O-C] | 0.1719 | 0.1719

Frag | 1 | Alkyl substituent on aromatic ring | -0.1145 | -0.1145

Frag | 1 | Unsubstituted phenyl group (C6H5-) | 0.2182 | 0.2182

Frag | 1 | Aromatic-CH2 | -0.0073 | -0.0073

Frag | 5 | Aromatic-H | -0.0954 | -0.4772

Frag | 1 | Methyl [-CH3] | -0.0796 | -0.0796

Frag | 3 | -CH2- [linear] | 0.0260 | 0.0780

Const| * | Equation Constant | | 0.8361

============+============================================+=========+=========

RESULT | Biowin7 (Anaerobic Linear Biodeg Prob) | | 0.6256

============+============================================+=========+=========

A Probability Greater Than or Equal to 0.5 indicates --> Biodegrades Fast

A Probability Less Than 0.5 indicates --> Does NOT Biodegrade Fast

Ready Biodegradability Prediction: (YES or NO)

----------------------------------------------

Criteria for the YES or NO prediction: If the Biowin3 (ultimate survey

model) result is "weeks" or faster (i.e. "days", "days to weeks", or

"weeks" AND the Biowin5 (MITI linear model) probability is >= 0.5, then

the prediction is YES (readily biodegradable). If this condition is not

satisfied, the prediction is NO (not readily biodegradable). This method

is based on application of Bayesian analysis to ready biodegradation data

(see Help). Biowin5 and 6 also predict ready biodegradability, but for

degradation in the OECD301C test only; using data from the Chemicals

Evaluation and Research Institute Japan (CERIJ) database.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradability of the substance was calculated using seven different Biowin 1-7 models of the BIOWIN v4.10 software. The results indicate that test chemical is expected to be readily biodegradable.

Executive summary:

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test chemical 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 test chemical is expected to be readily biodegradable.

Description of key information

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test chemical 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 test chemical is expected to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Biodegradability of test chemical was estimated by prediction and experimental studies of read across chemicals and their results are summarized below.

In first study the Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test chemical 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 test chemical is expected to be readily biodegradable.

Next study was experimental study in this 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 study was also experimental study 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 the 28-days Manometric respirometry test following the OECD guideline 301F was performed to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20± 1°C. Mixture of domestic waste water, surface soil and soil samples was used as a test inoculum for the study. This inoculum was collected and was mixed to get diluted suspension. The inoculum was kept aerobic until being used for experiment by supplying organic and inorganic sources required by micro flora to sustain at controlled laboratory conditions.  This gave the bacterial count as 10E7to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. OECD mineral medium was used for the study. The test system included control, test item and reference item. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 100 mg/L, while that of inoculum was 10mL. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % Degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (Sodium Benzoate) was also calculated using BOD & ThOD and was determined to be 75.80%. The mean BOD value (mg O2/l) in control on 28th day was 1.262 mg O2/l, thereby fulfilling the control validity criteria (i.e., The oxygen consumption of the inoculum blank is normally 20-30 mg O2/l and should not be greater than 60 mg/l in 28 days). Degradation of Sodium Benzoate exceeds 47.99 %after 7 days and 62.04 % after 14 days. The activity of the inoculums is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.967 mgO2sup>/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 considered to be readily biodegradable at 20 ± 1°C over a period of 28 days.

By considering results of all the studies mentioned above it is concluded that test chemical is readily biodegradable.