[μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening tests

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 and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

The supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

The data is predicted using the OECD QSAR toolbox version 3.3 with logKow as the primary descriptor.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt
- Molecular weight : 1101.8036 g/mol
- Smiles notation : [Na+].[Na+].[Na+].[Na+].O=N(=Nc1ccc2N=Nc3c4O[Cu-2]5(Oc2c1)OS(=O)(=O)c6ccc4c(c6)cc3S(=O)(=O)O5)c7ccc8N=Nc9c%10O[Cu-2]%11(Oc8c7)OS(=O)(=O)c%12ccc%10c(c%12)cc9S(=O)(=O)O%11
- InChl : 1S/C32H22N6O17S4.2Cu.4Na/c39-25-13-17(1-7-23(25)33-35-29-27(58(50,51)52)11-15-9-19(56(44,45)46)3-5-21(15)31(29)41)37-38(43)18-2-8-24(26(40)14-18)34-36-30-28(59(53,54)55)12-16-10-20(57(47,48)49)4-6-22(16)32(30)42;;;;;;/h1-14,39-42H,(H,44,45,46)(H,47,48,49)(H,50,51,52)(H,53,54,55);;;;;;/q;2*+2;4*+1/p-8/b35-33+,36-34+,38-37+;;;;;;
- Substance type : Organic
- Physical state : Liquid

Oxygen conditions:

aerobic

Inoculum or test system:

other: Microorganisms

Duration of test (contact time):

28 d

Based on:

not specified

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: BOD

Value:

0.8

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

Test substance undergoes 0.8% degradation by BOD in 28 days.

The prediction was based on dataset comprised from the following descriptors: BOD
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" or "b" or "c" or "d" )  and "e" )  and "f" )  and "g" )  and ("h" and ( not "i") )  )  and ("j" and "k" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Anion OR Aromatic compound OR Azo compound OR Cation OR Hydroxy compound OR Phenol OR Sulfonic acid derivative by Organic functional groups, Norbert Haider (checkmol) ONLY

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Alcohol, olefinic attach [-OH] OR Aliphatic Nitrogen, one aromatic attach [-N] OR Aromatic Carbon [C] OR Azo [-N=N-] OR Hydroxy, aromatic attach [-OH] OR Miscellaneous sulfide (=S) or oxide (=O) OR Olefinic carbon [=CH- or =C<] OR Oxygen, one aromatic attach [-O-] OR Suflur {v+4} or {v+6} OR Sulfonate, aromatic attach [-SO2-O] by Organic functional groups (US EPA) ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Aryl OR Azo OR Azoxy OR Fused carbocyclic aromatic OR Overlapping groups OR Phenol OR Sulfonic acid by Organic Functional groups (nested) ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Aryl OR Azo OR Azoxy OR Fused carbocyclic aromatic OR Naphtalene OR Phenol OR Sulfonic acid by Organic Functional groups ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Not calculated by Biodeg BioHC half-life (Biowin) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 1) ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 2) ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Non binder, MW>500 by Estrogen Receptor Binding

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Moderate binder, NH2 group OR Non binder, impaired OH or NH2 group OR Non binder, without OH or NH2 group OR Strong binder, NH2 group OR Strong binder, OH group OR Weak binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 604 Da

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 1.35E003 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test chemical [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt was estimated to be not readily biodegradable in water.

Executive summary:

Biodegradability of [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt (CAS no. 75173 -68 -1) is predicted using QSAR toolbox version 3.3 with logKow as the primary descriptor. Test substance undergoes 0.8% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt was estimated to be not readily biodegradable in water.

Description of key information

Biodegradability of [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt (CAS no. 75173 -68 -1) is predicted using QSAR toolbox version 3.3 (2018) with logKow as the primary descriptor. Test substance undergoes 0.8% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt was estimated to be not readily biodegradable in water.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Predicted data for the target compound [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt (CAS No. 75173-68-1) and various supporting weight of evidence studies for its structurally and functionally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done by SSS (2018) using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical[μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt(CAS No. 75173-68-1) was estimated.Test substance undergoes 0.8% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical[μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium saltwas estimated to be not readily biodegradable in water.

 

In a supporting weight of evidence study from experimental study report (Sustainability Support Services (Europe) AB, report no. 2519-30-4/01/2016/RBD, 2016) for the read across chemical Tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo))naphthalene-4,6-disulphonate (CAS no. 2519-30-4),28-days Manometric respirometry test following the OECD guideline 301F to determine the ready biodegradability of the read across item tetrasodium 1 -acetamido-2 -hydroxy-3 -(4 -((4 -sulphonato phenylazo)-7 -sulphonato-1 -naphthylazo))naphthalene-4,6 -disulphonate, CAS No. 2519 -30 -4. 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 30 mg/L, while that of inoculum was 10 ml/l. 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 BOD28 value of tetrasodium 1 -acetamido-2 -hydroxy-3 -(4 -((4 -sulphonatophenylazo)-7 -sulphonato-1 -naphthylazo))naphthalene-4,6 -disulphonate, CAS No. 2519 -30-4 was observed to be 0.050mgO2sup>/mg. ThOD was calculated as 1.088 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 4.596%.Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable at 20 ± 1°C over a period of 28 days.

 

For the read across chemical Disodium 3-[(2,4-dimethyl-5-sulphonatophenyl)azo]-4-hydroxynaphthalene-1-sulphonate (CAS no. 4548-53-2), 28-days Manometric respirometry testfollowing the OECD guideline 301Fto determine the ready biodegradability of the test item disodium 3- [(2,4 -dimethyl-5 -sulphonatophenyl)azo]-4 -hydroxynaphthalene-1 -sulphonate, CAS No. 4548 -53 -2 (Sustainability Support Services (Europe) AB, report no. 4548-53-2/01/2016/RBD, 2016). 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 30 mg/L, while that of inoculum was 10 ml/l. 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 BOD28 value of disodium 3-[(2,4-dimethyl-5-sulphonatophenyl)azo]-4-hydroxynaphthalene-1-sulphonate, CAS No. 4548-53-2 was observed to be 0.188 mgO2sup>/mg. ThOD was calculated as 1.464 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 12.807 %.Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable at 20± 1°C over a period of 28 days.

 

On the basis of above results for target chemical [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt (from OECD QSAR toolbox version 3.3, 2018) and for its read across substance (from UERL study report), it can be concluded that the test substance [μ-[[3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicopper, tetrasodium salt can be expected to be not readily biodegradable in nature.