Tetramethyl 2,2'-[1,4-phenylenebis[imino(1-acetyl-2-oxoethane-1,2-diyl)azo]]bisterephthalate

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil: simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
see attached justification

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Principles of method if other than guideline:

Estimation of results of OECD screening tests on ready biodegradation in water: CATALOGIC (v5.11.5) BOD 28 days MITI (OECD 301C) v06.07

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Parameter:

% degradation (O2 consumption)

Value:

ca. 32.35

Sampling time:

28 d

Details on results:

Model domain similarity:
- Parametric domain: 100%
- Structural domain: 61.54% (38.46% unknown)
- Mechanistic domain: 100%

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance is not readily biodegradable (according to OECD criteria)

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

Please refer to QMRF and QPRF in the section "Overall remarks" and "Executive summary", respectively.

Principles of method if other than guideline:

Prediction of ready biodegradability based on six QSAR models

GLP compliance:

no

Key result

Remarks on result:

other: Ready biodegradability prediction: Substance is not readily biodegradable.

Remarks on result:

other: Biowin1: Biodegrades Fast; Biowin2: Does Not Biodegrade Fast; Biowin3: Recalcitrant; Biowin4: Days; Biowin5: Does Not Biodegrade Fast; BIOWIN6: Does Not Biodegrade Fast

BIOWIN (v4.10) Program Results:

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

SMILES : CC(=O)C(N=Nc1c(ccc(c1)C(=O)OC)C(=O)OC)C(=O)Nc2ccc(cc2)NC(=O)C(N=Nc3c(

ccc(c3)C(=O)OC)C(=O)OC)C(=O)C

MOL FOR: C34 H32 N6 O12

MOL WT : 716.67

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

Biowin1 (Linear Model Prediction)   : Biodegrades Fast

Biowin2 (Non-Linear Model Prediction): Does Not Biodegrade Fast

Biowin3 (Ultimate Biodegradation Timeframe): Recalcitrant

Biowin4 (Primary Biodegradation Timeframe): Days

Biowin5 (MITI Linear Model Prediction)   : Does Not Biodegrade Fast

Biowin6 (MITI Non-Linear Model Prediction): Does Not Biodegrade Fast

Biowin7 (Anaerobic Model Prediction): Does Not Biodegrade Fast

Ready Biodegradability Prediction: NO

 

 

Type	Num	Biowin1 Fragment description	Coeff	Value
Frag	4	Ester  [-C(=O)-O-C]	0.1742	0.6967
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	0.2102	0.4203
Frag	2	Ketone  [-C-C(=O)-C-]	0.0068	0.0137
Frag	2	Azo group  [-N=N-]	-0.2418	-0.4837
MolWt	*	Molecular Weight Parameter		-0.3412
Const	*	Equation Constant		0.7475
Result	Biowin1 (Linear Biodeg Probability)			1.0534

Type	Num	Biowin2 Fragment description	Coeff	Value
Frag	4	Ester  [-C(=O)-O-C]	4.0795	16.3180
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	2.6913	5.3826
Frag	2	Ketone  [-C-C(=O)-C-]	-0.4530	-0.9060
Frag	2	Azo group  [-N=N-]	-8.2194	-16.4388
MolWt	*	Molecular Weight Parameter		-10.1767
Result	Biowin2 (Non-Linear Biodeg Probability)			0.0567

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	4	Ester  [-C(=O)-O-C]	0.1402	0.5608
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	-0.0542	-0.1084
Frag	2	Ketone  [-C-C(=O)-C-]	-0.0225	-0.0450
Frag	2	Azo group  [-N=N-]	-0.3004	-0.6007
MolWt	*	Molecular Weight Parameter		-1.5837
Const	*	Equation Constant		3.1992
Result	Biowin3 (Survey Model - Ultimate Biodeg)			1.4222

 

Type	Num	Biowin4 Fragment description	Coeff	Value
Frag	4	Ester  [-C(=O)-O-C]	0.2290	0.9158
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	0.2054	0.4109
Frag	2	Ketone  [-C-C(=O)-C-]	-0.0222	-0.0444
Frag	2	Azo group  [-N=N-]	-0.0528	-0.1056
MolWt	*	Molecular Weight Parameter		-1.0340
Const	*	Equation Constant		3.8477
Result	Biowin4 (Survey Model - Primary Biodeg)			3.9904

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	4	Ester  [-C(=O)-O-C]	0.3437	1.3749
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	0.1266	0.2533
Frag	2	Ketone  [-C-C(=O)-C-]	0.1177	0.2355
Frag	2	Azo group  [-N=N-]	-0.0459	-0.0917
Frag	10	Aromatic-H	0.0082	0.0822
Frag	6	Methyl [-CH3]	0.0004	0.0025
Frag	2	-CH- [linear]	-0.0507	-0.1013
MolWt	*	Molecular Weight Parameter		-2.1321
Const	*	Equation Constant		0.7121
Result	Biowin5 (MITI Linear Biodeg Probability)			0.3353

 

Type	Num	Biowin6 Fragment description	Coeff	Value
Frag	4	Ester  [-C(=O)-O-C]	2.4462	9.7846
Frag	2	Amide  [-C(=O)-N or -C(=S)-N]	0.8859	1.7717
Frag	2	Ketone  [-C-C(=O)-C-]	0.8334	1.6669
Frag	2	Azo group  [-N=N-]	-10.6129	-21.2258
Frag	10	Aromatic-H	0.1201	1.2014
Frag	6	Methyl [-CH3]	0.0194	0.1166
Frag	2	-CH- [linear]	-0.0998	-0.1995
MolWt	*	Molecular Weight Parameter		-20.6893
Result	Biowin6 (MITI Non-Linear Biodeg Probability)			0.0000

A probability greater than or equal to 0.5 indicates --> readily degradable

A probability less than 0.5 indicates --> not readily degradable

 

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Executive summary:

QPRF: BIOWIN v4.10

 

1.	Substance	See “Test material identity”
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint				Biodegradability
		Dependent variable				Biodegradability
3.2	Algorithm (OECD Principle 2)	Model or submodel name				BIOWIN
		Model version				v. 4.10
		Reference to QMRF				QMRF: Estimation of Aerobic Biodegradability using BIOWIN v4.10 (EPI Suite v4.11): BIOWIN1 to BIOWIN6 and Ready Biodegradability Prediction
		Predicted value (model result)				See “Results and discussion”
		Input for prediction				- Chemical structure via CAS number or SMILES
		Descriptor values				- Structure fragments - Molecular weight
3.3	Applicability domain (OECD principle 3)	Domains (Appendix D, On-Line BIOWIN User’s Guide):
		1) Molecular weight				See below (Assessment of estimation domain)
		2) Fragments:				See below (Assessment of estimation domain)
3.4	The uncertainty of the prediction (OECD principle 4)	Parameter	BIOWIN model
			1	2	3		4	5	6
		Total correct	264 / 295	275 / 295	167 / 200		165 / 200	485 / 589	488 / 589
		% correct, total	89.5	93.2	83.5		82.5	82.3	82.9
		% correct, fast	97.3 (181 / 186)	97.3 (181 / 186)	93.5 (101 / 108)		84.9 (101 / 119)	79.1 (201 / 254)	80.3 (204 / 254)
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	The chemical structure influences the biodegradability of the substance. Therefore, chemical fragments were selected having a potential effect on biodegradability. In order to be able to predict the biodegradability probability of substances without these specific fragments, the molecular weight was integrated into the models.

 

References

- US EPA (2012). On-Line BIOWIN User’s Guide.

 

 

Assessment of estimation domain (molecular weight, fragments):

 

Model:	BIOWIN v4.10
Substance:	tetramethyl 2,2'-{1,4-phenylenebis[imino(1,3-dioxobutane-2,1-diyl)diazene-2,1-diyl]}diterephthalate
CAS-#:	68516-73-4
SMILES:	CC(=O)C(N=Nc1c(ccc(c1)C(=O)OC)C(=O)OC)C(=O)Nc2ccc(cc2)NC(=O)C(N=Nc3c( ccc(c3)C(=O)OC)C(=O)OC)C(=O)C
Molecular weight (g/mol):	716.67

 

AppendixD - Fragment Coefficients for Biodegradation Models

 

BIOWIN1 and BIOWIN2: Linear / Non-Linear Biodegradability
Fragment description	Coefficient		Training set fragment count			No. of instances of each bond found for the current substance
	Linear	Non-linear	Min	Max	No. of compounds in training set containing the fragment
Ester [-C(=O)-O-C]	0.17418	4.0795	-	3	23	4
Amide [-C(=O)-N or -C(=S)-N]	0.21015	2.6913	-	1	12	2
Ketone [-C-C(=O)-C-]	0.00683	-0.453	-	2	12	2
Azo group [-N=N-]	-0.24183	-8.2194	-	1	2	2
Molecular Weight	---	---	31.06	697.7		out of range

 

BIOWIN3 and BIOWIN4: Ultimate / Primary biodegradability
Fragment description	Coefficient		Training set fragment count			No. of instances of each bond found for the current substance
	Ultimate	Primary	Min	Max	No. of compounds in training set containing the fragment
Ester [-C(=O)-O-C]	0.14021	0.22896	-	4	25	4
Amide [-C(=O)-N or -C(=S)-N]	-0.05421	0.20543	-	1	13	2
Ketone [-C-C(=O)-C-]	-0.02248	-0.02222	-	4	10	2
Azo group [-N=N-]	-0.30036	-0.05279	-	1	3	2
Molecular Weight	---	---	53.06	697.65	-	out of range

 

BIOWIN5 and BIOWIN6: MITI Biodegradability Coefficients (Linear / Non-Linear)
Fragment description	Coefficient		Training set fragment count			No. of instances of each bond found for the current substance
	Linear	Non-Linear	Min	Max	No. of compounds in training set containing the fragment
Ester [-C(=O)-O-C]	0.343735	2.44616254	-	3	46	4
Amide [-C(=O)-N or -C(=S)-N]	0.126629	0.88586757	-	2	24	2
Ketone [-C-C(=O)-C-]	0.117739	0.83343688	-	2	25	2
Azo group [-N=N-]	-0.045873	-10.6129184	-	1	2	2
Aromatic-H	0.008218	0.12014128	-	15	302	10
Methyl [-CH3]	0.000411	0.01942827	-	9	295	6
-CH- [linear]	-0.050672	-0.09977022	-	4	63	2
Molecular Weight	---	---	30.02	959.2	-	in range

 

Fragment description	Coefficient		Min	Max	No. of compounds in training set containing the fragment	No. of instances of each bond found for the current substance
Molecular Weight	---	---	46.07	885.46		in range

 

Cross-reference 3

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD 318

At any of the time points mentioned in the TG-318, the influence of Ca is critical. Regardless of pH, the pigment is unstable in 10 mM Ca, representing high water hardness.

After 6h, the samples showed high dispersion stability in 0 mM Ca and on a lower level intermediate stability in 1 mM and 10 mM Ca.

After 24 hours the stability in 0 mM Ca became intermediate. For the samples in 1 and 10 mM Ca the stability was low.

Full results of the dispersion stability in the presence of NOM
	Ca(NO3)2	Stability after 6h	Standard deviation	Stability after 15h	Standard deviation	Stability after 24h	Standard deviation
	[mM]	[%]	[%]	[%]	[%]	[%]	[%]
pH 4	0	91.2	2.7	78.4	4.5	64.7	4.5
pH 4	1	16.2	1.5	5.8	0.3	2.9	0.4
pH 4	10	11.5	0.7	4.1	0.6	2.9	0.8
.
pH 7	0	89.4	0.9	73.5	1.2	60.1	1.3
pH 7	1	13.6	0.5	4.6	0.4	2.8	0.4
pH 7	10	12.7	1.3	4.9	0.4	2.9	0.4
.
pH 9	0	94	0.2	84.5	0.7	71.5	1
pH 9	1	13.9	0.9	5.3	0.5	3.8	0.4
pH 9	10	11.5	0.8	5.7	0.2	4.6	0.1

 

 

To rationalize the observed dispersion stability, we finally checked the particle size distribution directly in the environmental medium. We applied the NanoDefine method of Analytical Ultracentrifugation. The centrifugation parameters are given in the methods section.

As required by TG318, paragraph 31, the tested nanomaterial was pre-wetted in ultrapure water and left in the form of wet-paste for 24 h. The TG318 requires this step “to insure the proper interaction of nanomaterial surface with ultrapure water.” We visually observed incomplete wetting, and so any ensuing measurement would have been incorrect. In accord with the NanoGenoTox dispersion protocol, a drop of ethanol was added, successfully transferred the powder into a paste, which was then further diluted as specified in the TG318

The observed size distributions confirm the moderate agglomeration at 1 mM Ca, pH7, with NOM. If the particles would have been significantly dissolved, no size distribution would be observable at all by this method, which relies on the detection of the movement of particles during centrifugal separation.

Additionally, the centrifugation methods include a determination of the remaining absorption after centrifugation, fully consistent with the conventional determination of the dissolved fraction after centrifugation as recommended by the TG-318. The remaining absorption was measured at ca. 0.02. This is a fraction of 1% of the initial absorption, but actually is close to the LOD of the built-in UV/Vis detector. Considering the LOD, between 0% and 2% of the sample may have been dissolved.

All evidence combined, the results after centrifugation confirm that at least 98% of the observed dispersion stability has to be attributed to the particles, not to dissolution.

Executive summary:

At any of the time points mentioned in the TG-318, the influence of Ca is critical. Regardless of pH, the pigment is unstable in 10 mM Ca, representing high water hardness.

After 6h, the samples showed high dispersion stability in 0 mM Ca and on a lower level intermediate stability in 1 mM an 10 mM Ca.

After 24 hours the stability in 0 mM Ca became intermediate. For the samples in 1 and 10 mM Ca the stability was low.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Tetramethyl 2,2'-[1,4-phenylenebis[imino(1-acetyl-2-oxoethane-1,2-diyl)azo]]bisterephthalate

EC Number:

271-176-6

EC Name:

Tetramethyl 2,2'-[1,4-phenylenebis[imino(1-acetyl-2-oxoethane-1,2-diyl)azo]]bisterephthalate

Cas Number:

68516-73-4

Molecular formula:

C34H32N6O12

IUPAC Name:

tetramethyl 2,2'-{1,4-phenylenebis[imino(1,3-dioxobutane-2,1-diyl)diazene-2,1-diyl]}diterephthalate

Test material form:

solid: nanoform, no surface treatment

Details on test material:

- State of aggregation:
- Particle size distribution:

- Shape of particles:
- Surface area of particles: BET = 46.3 m2/g
- Crystal structure: crystalline
- Coating: none
- Batch: 13007010
- solid yellow

Results and discussion

Transformation products:

not specified