Methyl 5-nitrohydrogen.isophthalate

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 4.10. Estimates 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):

2.76 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.

Biowin 1 and 2, are intended to convey a general indication of biodegradability under aerobic conditions, and not for any particular medium.
Biowin 1 (Linear model)
The fast biodegradation probability for any compound is calculated by summing, for all the fragments present in that compound, the fragment coefficient multiplied by the number of instances of the fragment in the compound (for MW, the value of that parameter is multiplied by its coefficient), and then adding this summation to the equation constant which is 0.7475. The summed values for each fragment coefficient multiplied by the number of instances appear in the "VALUE" column of the linear results screen.

Biowin 2 (Non-linear model)
Calculation of the fast biodegradation probability for any compound begins by summing, for all the fragments present in that compound, the fragment coefficient multiplied by the number of instances of the fragment in the compound (for MW, the value of that parameter is multiplied by its coefficient), then adding this summation to the equation constant which is 3.0087. The summed values for each fragment coefficient multiplied by the number of instances appear in the "VALUE" column of the non-linear results screen. The non-linear fast biodegradation probability is then calculated from the logistic equation as follows, where total = 3.0087 + the summation as described above:

Biowin 3 and 4 yield estimates for the time required to achieve complete ultimate and primary biodegradation in a typical or "evaluative" aquatic environment.

Biowin 5 and 6 are predictive models for assessing a compound’s biodegradability in the Japanese MITI (Ministry of International Trade and Industry) ready biodegradation test; i.e. OECD 301C. These models use an approach similar to that used to develop Biowin1 and 2. This protocol for determining ready biodegradability is among six officially approved as ready biodegradability test guidelines of the OECD (Organization for Economic Cooperation and Development). A total dataset of 884 chemicals was compiled to derive the fragment probability values that are applied in this MITI Biodegradability method. The dataset consists of 385 chemical that were critically evaluated as "readily degradable" and 499 chemicals that were critically evaluated as "not readily biodegradable".

Biowin 7, the anaerobic biodegradation model, is the most recent. As for the other Biowin models, multiple (linear) regression against molecular fragments was used to develop the model, which predicts probability of rapid degradation in the "serum bottle" anaerobic biodegradation screening test. This endpoint is assumed to be predictive of degradation in a typical anaerobic digester. Biowin7 estimates the probability of fast biodegradation under methanogenic anaerobic conditions; specifically, under the conditions of the "serum bottle" anaerobic biodegradation screening test (Meylan et al. 2007). A total of 169 compounds with serum bottle test data were identified for use in model development.

Out of seven different Biowin models, Biowin model 3 and 4 will help in estimating biodgeradability of the test chemical which was described as below-

Ultimate Biodegradation Timeframe and Primary Biodegradation Timeframe (Biowin 3 and 4)
These two models estimate the time required for "complete" ultimate and primary biodegradation.  Primary biodegradation is the transformation of a parent compound to an initial metabolite.  Ultimate biodegradation is the transformation of a parent compound to carbon dioxide and water, mineral oxides of any other elements present in the test compound, and new cell material. Then the rating was given to each model, which indicates the time required to achieve ultimate and primary biodegradation in a typical or "evaluative" aquatic environment. The ratings for each compound were averaged to obtain a single value for modeling.  The ultimate or primary rating of a compound is calculated by summing, for all the fragments present in that compound.

Key result

Parameter:

other: Half-life

Value:

50

Sampling time:

2.76 wk

Remarks on result:

other: readily biodegradable as estimated by BIOWIN model

Details on results:

Biowin1 (Linear Model Prediction) : 0.6864: Biodegrades Fast
Biowin2 (Non-Linear Model Prediction): 0.9782: Biodegrades Fast
Biowin3 (Ultimate Biodegradation Timeframe): 2.7601: Weeks
Biowin4 (Primary Biodegradation Timeframe): 3.6512: Days-Weeks
Biowin5 (MITI Linear Model Prediction) : 0.6005: Biodegrades Fast
Biowin6 (MITI Non-Linear Model Prediction): 0.2484: Does Not Biodegrade Fast
Biowin7 (Anaerobic Model Prediction): 0.6936: Biodegrades Fast
Ready Biodegradability Prediction: YES

BIOWIN (v4.10) Program Results:

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

SMILES : O=C(OC)c(cc(N(=O)(=O))cc1C(=O)O)c1

CHEM : 1,3-Benzenedicarboxylic acid, 5-nitro-, monomethyl ester

MOL FOR: C9 H7 N1 O6

MOL WT : 225.16

--------------------------- 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): Does Not Biodegrade Fast

Biowin7 (Anaerobic Model Prediction): Biodegrades Fast

Ready Biodegradability Prediction: YES

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

TYPE | NUM | Biowin1 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 1 | Aromatic acid [-C(=O)-OH] | 0.1769 | 0.1769

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

Frag | 1 | Aromatic nitro [-NO2] | -0.3050 | -0.3050

MolWt| * | Molecular Weight Parameter | | -0.1072

Const| * | Equation Constant | | 0.7475

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

RESULT | Biowin1 (Linear Biodeg Probability) | | 0.6864

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

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

TYPE | NUM | Biowin2 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 1 | Aromatic acid [-C(=O)-OH] | 2.4224 | 2.4224

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

Frag | 1 | Aromatic nitro [-NO2] | -2.5086 | -2.5086

MolWt| * | Molecular Weight Parameter | | -3.1973

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

RESULT | Biowin2 (Non-Linear Biodeg Probability) | | 0.9782

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

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 | Aromatic acid [-C(=O)-OH] | 0.0879 | 0.0879

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

Frag | 1 | Aromatic nitro [-NO2] | -0.1696 | -0.1696

MolWt| * | Molecular Weight Parameter | | -0.4976

Const| * | Equation Constant | | 3.1992

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

RESULT | Biowin3 (Survey Model - Ultimate Biodeg) | | 2.7601

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

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

TYPE | NUM | Biowin4 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 1 | Aromatic acid [-C(=O)-OH] | 0.0077 | 0.0077

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

Frag | 1 | Aromatic nitro [-NO2] | -0.1084 | -0.1084

MolWt| * | Molecular Weight Parameter | | -0.3248

Const| * | Equation Constant | | 3.8477

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

RESULT | Biowin4 (Survey Model - Primary Biodeg) | | 3.6512

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

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 | Aromatic acid [-C(=O)-OH] | 0.3770 | 0.3770

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

Frag | 1 | Aromatic nitro [-NO2] | -0.1876 | -0.1876

Frag | 3 | Aromatic-H | 0.0082 | 0.0247

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

MolWt| * | Molecular Weight Parameter | | -0.6698

Const| * | Equation Constant | | 0.7121

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

RESULT | Biowin5 (MITI Linear Biodeg Probability) | | 0.6005

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

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

TYPE | NUM | Biowin6 FRAGMENT DESCRIPTION | COEFF | VALUE

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

Frag | 1 | Aromatic acid [-C(=O)-OH] | 2.4449 | 2.4449

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

Frag | 1 | Aromatic nitro [-NO2] | -2.4035 | -2.4035

Frag | 3 | Aromatic-H | 0.1201 | 0.3604

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

MolWt| * | Molecular Weight Parameter | | -6.5001

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

RESULT |Biowin6 (MITI Non-Linear Biodeg Probability)| | 0.2484

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

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 | Aromatic acid [-C(=O)-OH] | 0.2656 | 0.2656

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

Frag | 1 | Aromatic nitro [-NO2] | -0.2141 | -0.2141

Frag | 3 | Aromatic-H | -0.0954 | -0.2863

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

Const| * | Equation Constant | | 0.8361

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

RESULT | Biowin7 (Anaerobic Linear Biodeg Prob) | | 0.6936

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

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 the test chemical is expected to be readily biodegradable.

Executive summary:

Estimation Programs Interface Suite (2018) 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 (2018) 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

Predicted data for the test chemical and various supporting weight of evidence studies for its structurally similar read across chemical were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction using the Estimation Programs Interface Suite (2018), the biodegradation potential of the test chemical 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 test chemical is expected to be not readily biodegradable.

 

In a supporting weight of evidence study from study report (2018) for the test chemical,28-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. 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 (reference item) was also calculated using BOD & ThOD and was determined to be 75.3%. Degradation of Sodium Benzoate exceeds 46.38% on 7 days & 61.44% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 0.77 mgO2/mg. ThOD was calculated as 1.05 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 73.33%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

 

Another biodegradation study using a batch test in an open system was conducted for 20 days for evaluating the biodegradability of test chemical (from peer reviewed journal, handbook authoritative databases and secondary source, 2017). Adapted activated sludge was used as a test inoculum obtained from a sewage plant is cultivated in a1000ml volumetric cylinder. The mixture is aerated with pressure air. Every day 200 ml of the mixture is driven off so that the sludge age is 5 days. After driving off the 200ml of the mixture aeration is interrupted, and after sedimentation ca.600ml of the liquid phase is driven off. The residue (200 ml of the thickened activated sludge) is diluted with tap water to the volume ofca.800 ml and 600 mg/l of starch or glucose, 600 mg/l of peptone, 25 ml of a phosphate buffer pH 7.2, and the solution of the tested compound are added. Then the mixture in the cylinder is made up to 1000ml with tap water and aerated for 23 h (the recirculation ratio is 0-25). After this period the procedure is repeated. Test chemical conc. used for the study was 200 mg/l based on COD. To 1000-1500ml of the biological medium such amount of the solution of the substance tested is added that the initial COD is 200 mg/l. Then such an amount of the adapted activated sludge, washed and thickened by sedimentation, is dosed to the medium that the concentration of the dry matter is 100 mg/l. Simultaneously, a blank test is prepared. The beaker is placed in a dark room with a roughly 3 constant temperature of 20±3°C on an electromagnetic stirrer and a pH of 7.2 for 120 hrs. The initial value of COD or organic carbon of the liquid phase are determined. Samples filtered or centrifuged before analysis, are taken at suitable intervals. The decrease of the tested substance in the liquid phase is evaluated by determining COD or organic carbon. The results are compared with those of a blank test and standard compound decomposition. With the degree of degradation also the average specific rate of degradation is determined, expressed in terms of mg COD (or organic carbon) removed by a gram of dry matter of the activated sludge per hour. The percentage degradation of test chemical was determined to be 93.4% by using COD removal parameter in < 20 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in nature.

 

For the test chemical from authoritative databases and secondary source, biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of test chemical. The study was performed according toOECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I) under aerobic conditions. Activated sludge was used as a test inoculums for the study. 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 test chemical was determined to be 99, 96 and 100% by BOD, TOC removal and HPLC parameter in 14 days. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

On the basis of above results of the test chemical, it can be concluded that the test chemical can be expected to be readily biodegradable in nature.