Octadecyl stearate

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:

accepted calculation method

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:

no

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):

2.749 mo

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:

2.749 mo

Remarks on result:

other: Not readily biodegradable as estimated by BIOWIN model.

Details on results:

Biowin1 (Linear Model Prediction) : 0.8829: Biodegrades Fast
Biowin2 (Non-Linear Model Prediction): 0.9589: Biodegrades Fast
Biowin3 (Ultimate Biodegradation Timeframe): 2.7494: Weeks-Months
Biowin4 (Primary Biodegradation Timeframe): 3.8401: Days
Biowin5 (MITI Linear Model Prediction) : 1.0899: Biodegrades Fast
Biowin6 (MITI Non-Linear Model Prediction): 0.9755: Biodegrades Fast
Biowin7 (Anaerobic Model Prediction): 1.0710: Biodegrades Fast
Ready Biodegradability Prediction: NO

BIOWIN (v4.10) Program Results:

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

SMILES : O=C(OCCCCCCCCCCCCCCCCCC)CCCCCCCCCCCCCCCCC

CHEM : Octadecanoic acid, octadecyl ester

MOL FOR: C36 H72 O2

MOL WT : 536.97

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

Biowin1 (Linear Model Prediction) : Biodegrades Fast

Biowin2 (Non-Linear Model Prediction): Biodegrades Fast

Biowin3 (Ultimate Biodegradation Timeframe): Weeks-Months

Biowin4 (Primary Biodegradation Timeframe): Days

Biowin5 (MITI Linear Model Prediction) : Biodegrades Fast

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

Biowin7 (Anaerobic Model Prediction): Biodegrades Fast

Ready Biodegradability Prediction: NO

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

TYPE | NUM | Biowin1 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 2 | Linear C4 terminal chain [CCC-CH3] | 0.1084 | 0.2169

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

MolWt| * | Molecular Weight Parameter | | -0.2556

Const| * | Equation Constant | | 0.7475

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

RESULT | Biowin1 (Linear Biodeg Probability) | | 0.8829

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

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

TYPE | NUM | Biowin2 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 2 | Linear C4 terminal chain [CCC-CH3] | 1.8437 | 3.6874

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

MolWt| * | Molecular Weight Parameter | | -7.6250

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

RESULT | Biowin2 (Non-Linear Biodeg Probability) | | 0.9589

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

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 | 2 | Linear C4 terminal chain [CCC-CH3] | 0.2983 | 0.5967

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

MolWt| * | Molecular Weight Parameter | | -1.1866

Const| * | Equation Constant | | 3.1992

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

RESULT | Biowin3 (Survey Model - Ultimate Biodeg) | | 2.7494

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

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

TYPE | NUM | Biowin4 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 2 | Linear C4 terminal chain [CCC-CH3] | 0.2691 | 0.5381

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

MolWt| * | Molecular Weight Parameter | | -0.7747

Const| * | Equation Constant | | 3.8477

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

RESULT | Biowin4 (Survey Model - Primary Biodeg) | | 3.8401

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

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 | 2 | Methyl [-CH3] | 0.0004 | 0.0008

Frag | 33 | -CH2- [linear] | 0.0494 | 1.6307

MolWt| * | Molecular Weight Parameter | | -1.5975

Const| * | Equation Constant | | 0.7121

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

RESULT | Biowin5 (MITI Linear Biodeg Probability) | | 1.0899

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

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

TYPE | NUM | Biowin6 FRAGMENT DESCRIPTION | COEFF | VALUE

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

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

Frag | 2 | Methyl [-CH3] | 0.0194 | 0.0389

Frag | 33 | -CH2- [linear] | 0.4295 | 14.1733

MolWt| * | Molecular Weight Parameter | |-15.5018

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

RESULT |Biowin6 (MITI Non-Linear Biodeg Probability)| | 0.9755

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

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 | 2 | Linear C4 terminal chain [CCC-CH3] | -0.3177 | -0.6355

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

Frag | 2 | Methyl [-CH3] | -0.0796 | -0.1591

Frag | 33 | -CH2- [linear] | 0.0260 | 0.8577

Const| * | Equation Constant | | 0.8361

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

RESULT | Biowin7 (Anaerobic Linear Biodeg Prob) | | 1.0710

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

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:

no

Interpretation of results:

not 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 not readily biodegradable.

Executive summary:

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test compound 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 not readily biodegradable.

Description of key information

Estimation Programs Interface Suite was run to predict the biodegradation potential of the test compound 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 not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Predicted data for the target compound and various supporting weight of evidence studies for its closest read across substance were reviewed for the biodegradation end point which are summarized as below:

The first study was predicted data study in this the Estimation Programs Interface Suite was run to predict the biodegradation potential of the test compound 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 not readily biodegradable.

In a supporting weight of evidence study from authoritative database, biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 B "Ready Biodegradability: Modified Sturm Test (CO2 evolution)" at a temperature of 22±2°C. Bacteria collected from activated sludge of the sewage treatment plant of CH 4153 Reinach on 2/6/89 was used as a test inoculum. Initial test substance conc. used in the study was 11.3 and 23.9 mg/l, respectively. The test medium was prepared according to the method described in the guideline. 2-liter flasks equipped with gas inlet and magnetic stirrers were used as the test vessels. Aeration consisted of approx. 25 ml/min air free of carbon dioxide. 1200 ml of the mineral solution with the inoculum was aerated for 24 hours in the test vessel. In 300 ml mineral solution 0.5 ml nonylphenol 10E05PO (solution of 30 mg in 100 ml bidist. Water) and 16.3 rsp. 29.9 mg of test substance were added and homogenized. This solution was given to the test vessel which was immediately connected to the CO2 traps. The biodegradation was calculated on the basis of the theoretical carbon content of the test substance and the cumulative quantities of carbon dioxide determined on the days of measurements. Determination of the initial CO2 of the 0.05 N sodium hydroxide and the C02, absorbed in the absorbers filled with 200 ml 0.05 N sodium hydroxide on the days 7, 10, 13, 17, 20, 24, 27, and 28. Blank consisted of water as specified in the guideline containing 0.5 ml of the nonylphenol 10E05PO solution. 20 mg/L with 0.5 ml of the nonylphenol 10E05PO was used as a reference substance in the study. The percentage degradation of test substance was determined to be 15 and 2% by CO2 evolution parameter in 28 days at a chemical conc. of 11.3 and 23.9 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

The next biodegradation study was conducted in accordance with OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test) for 28 days for evaluating the percentage biodegradability of test substance. Mixed culture was used as test inoculum for the study. Inoculum was collected form waste water treatment plant. Initial test substance conc. used in the study was 5-10 mg/l based on ThOD .  The percentage degradation of test substance 18 % by oxygen uptake parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

On the basis of above results for target chemical and for its read across substance, it can be concluded that the test substance can be expected to be not readily biodegradable in nature.