2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium 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 : 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt
- Molecular formula : C42H26MgN7NaO13S4
- Molecular weight : 1012.2624 g/mol
- Smiles notation : C1=CC=C(C=C1)NC2=CC3=C(C=C2)C(=O)C(=NNC4=CC=C(C5=CC=CC=C54)N=NC6=C7C=C(C=CC7=C(C=C6)N=NC8=C(C=CC(=C8)S(=O)(=O)[O-])S(=O)(=O)[O-])S(=O)(=O)[O-])C(=C3)S(=O)(=O)O.[Na+].[Mg+2]
- InChl : 1S/C42H29N7O13S4.Mg.Na/c50-42-29-13-10-26(43-25-6-2-1-3-7-25)20-24(29)21-40(66(60,61)62)41(42)49-47-35-16-15-34(30-8-4-5-9-31(30)35)44-46-37-18-17-36(32-14-11-27(22-33(32)37)63(51,52)53)45-48-38-23-28(64(54,55)56)12-19-39(38)65(57,58)59;;/h1-23,43,50H,(H,51,52,53)(H,54,55,56)(H,57,58,59)(H,60,61,62);;/q;+2;+1/p-3/b46-44+,48-45+,49-47+;;
- Substance type : Organic
- Physical state : Solid

Oxygen conditions:

aerobic

Inoculum or test system:

other: Micro-organisms

Duration of test (contact time):

28 d

Based on:

not specified

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: BOD

Value:

6.714

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

Test substance undergoes 6.7% 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 7 nearest neighbours
Domain  logical expression:Result: In Domain

(((((((("a" or "b" or "c" or "d" )  and "e" )  and "f" )  and ("g" and ( not "h") )  )  and ("i" and ( not "j") )  )  and ("k" and ( not "l") )  )  and ("m" and ( not "n") )  )  and ("o" and "p" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Amine OR Aromatic compound OR Azo compound OR Hydroxy compound OR Phenol OR Secondary amine OR Secondary aromatic amine OR Sulfonic acid 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 Aliphatic Nitrogen, two aromatic attach [-N-] OR Aromatic Carbon [C] OR Azo [-N=N-] OR Hydroxy, aromatic attach [-OH] OR Hydroxy, sulfur attach [-OH] OR Magnesium [Mg] OR Miscellaneous sulfide (=S) or oxide (=O) OR Nitrogen, two or tree olefinic attach [>N-] OR No functional group found OR Olefinic carbon [=CH- or =C<] OR Oxygen, one aromatic attach [-O-] OR Suflur {v+4} or {v+6} OR Sulfinic acid [-S(=O)OH] 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 Aromatic amine OR Aryl OR Azo OR Fused carbocyclic aromatic OR No functional group found 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 Aromatic amine OR Aryl OR Azo 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 days - weeks AND weeks - months by Biodeg primary (Biowin 4) ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OASIS v.1.3

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >>  Michael-type addition, quinoid structures OR AN2 >>  Michael-type addition, quinoid structures >> Quinoneimines OR AN2 >>  Michael-type addition, quinoid structures >> Quinones OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> Fused-Ring Primary Aromatic Amines OR Non-covalent interaction >> DNA intercalation >> Quinones OR Radical OR Radical >> Generation of reactive oxygen species OR Radical >> Generation of reactive oxygen species >> Thiols OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Primary Aromatic Amines OR Radical >> Radical mechanism via ROS formation (indirect) >> Quinones OR Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines OR Radical >> ROS formation after GSH depletion (indirect) OR Radical >> ROS formation after GSH depletion (indirect) >> Quinoneimines OR SN1 OR SN1 >> Nucleophilic attack after carbenium ion formation OR SN1 >> Nucleophilic attack after carbenium ion formation >> N-Nitroso Compounds OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Fused-Ring Primary Aromatic Amines OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines OR SN1 >> Nucleophilic attack after nitrenium and/or carbenium ion formation OR SN1 >> Nucleophilic attack after nitrenium and/or carbenium ion formation >> N-Nitroso Compounds OR SN2 OR SN2 >> Alkylation, direct acting epoxides and related OR SN2 >> Alkylation, direct acting epoxides and related >> Epoxides and Aziridines OR SN2 >> Direct acting epoxides formed after metabolic activation OR SN2 >> Direct acting epoxides formed after metabolic activation >> Quinoline Derivatives OR SN2 >> SN2 at an activated carbon atom OR SN2 >> SN2 at an activated carbon atom >> Quinoline Derivatives by DNA binding by OASIS v.1.3

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OECD

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> P450 Mediated Activation to Isocyanates or Isothiocyanates OR Acylation >> P450 Mediated Activation to Isocyanates or Isothiocyanates >> Formamides OR Michael addition OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Arenes OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Hydroquinones OR SN1 OR SN1 >> Carbenium Ion Formation OR SN1 >> Carbenium Ion Formation >> Allyl benzenes OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic azo OR SN1 >> Nitrenium Ion formation >> Primary aromatic amine OR SN1 >> Nitrenium Ion formation >> Secondary aromatic amine OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine by DNA binding by OECD

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Acidic [90,100] AND Basic [20,30) AND No pKa value AND No pKb value by Ionization at pH = 1

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Acidic [0,10) OR Acidic [70,80) OR Basic [0,10) OR Basic [10,20) OR Basic [30,40) OR Basic [40,50) OR Basic [70,80) OR Basic [90,100] by Ionization at pH = 1

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Acid moiety AND Inorganic Compound AND Phenols AND Salt AND SHOULD NOT BE PROFILED by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Surfactants-Anionic by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "o"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 219 Da

Domain logical expression index: "p"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 427 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The test chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt was estimated to be not readily biodegradable in water.

Executive summary:

Biodegradability of 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (CAS no. 93941 -74 -3) is predicted using QSAR toolbox version 3.3 with logKow as the primary descriptor. Test substance undergoes 6.7% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt was estimated to be not readily biodegradable in water.

Description of key information

Biodegradability of 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (CAS no. 93941 -74 -3) is predicted using QSAR toolbox version 3.3 (2018) with logKow as the primary descriptor. Test substance undergoes 6.7% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium 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 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (CAS No. 93941-47-3) and various supporting weight of evidence studies for its structurally and functionally 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 chemical2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt(CAS No. 93941-47-3) was estimated.Test substance undergoes 6.7% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium saltwas estimated to be not readily biodegradable in water.

 

In a supporting weight of evidence study from study report (Sustainability Support Services (Europe) AB, Report no. 4548-53-2/01/2016/RBD, 2016) 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 301F to determine the ready biodegradability of the read across item disodium 3- [(2,4 -dimethyl-5 -sulphonatophenyl)azo]-4 -hydroxynaphthalene-1 -sulphonate. 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 mgO2sup>/mg. ThOD was calculated as mgO2/mg. Accordingly, the % degradation of the read across item Disodium 3-[(2,4-dimethyl-5-sulphonatophenyl)azo]-4-hydroxynaphthalene-1-sulphonate 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.

 

For the read across chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt (CAS no. 2611-82-7) from peer reviewed journal (U. Pagga and O. Brown, 1986), biodegradation study was carried out for 48 days for evaluating the percentage biodegradation of the read across chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt using modified OECD Guideline 302B. Activated sludge was used as a test inoculum. The sources of the activated sludge were treatment plants conveniently located to the laboratories carrying out the test. These treatment plants received communal and/or industrial wastewater. Concentration of inoculum i.e, activated sludge used was 0.5 g/l and initial test substance conc. used in the study was 100 mg/l. Analytical methods involve the measurement of extinction at absorption maximum 412 nm and DOC (dissolved organic carbon).The percentage degradation of substance 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt was determined to be 5% by DOC removal. Based on the limit values for classification of Static Test – the test chemical was classified in CATEGORY ‘D’. Thus, the substance 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt is considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for evaluating the percentage biodegradability of read across substance 1,3 -Naphthalenedisulfonic acid, 7 -hydroxy-8 -((4 -sulfo-1 -naphthalenyl)azo)-, trisodium salt (CAS no. 2611 -82 -7) (Toshihide Saito et. al, 1984). Activated sludge was used as a test inoculum obtained from municipal sewage. Test substance of conc. 500 mg/l was prepared and diluted as needed. The COD measurement was performed by the potassium dichromate reflux method based on Japanese Industrial Standards. In the BOD measurement, a sample solution was taken into a container. Then JIS-BOD testing solutions, i.e. 3 ml of A solution and 1 ml of B, C, D solutions were added to the sample solution, respectively. Then 5 ml of the supernatant of the municipal sewage activated sludge was added to the sample solution and diluted to 300 ml with water. Immediately, the BOD-time curve was recorded at 20~ using an Ohkura OM-200I type coulometer. The TOC measurement was carried out by a Yanagimoto TOC-ILW.BOD5, COD, ThOD and TOC value of the test chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt was determined to be 0.021, 0.65, 1.23 and 0.20 g/g, respectively. The BOD5/TOC ratio of chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt was determined to be 0.11 (i.e. ranges in between 0.08-0.89), indicating that the chemical is highly resistant to aerobic biodegradation. Thus, based on this value BOD5/TOC value, it can be concluded that the chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt is not readily biodegradable in nature.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for read across substancedisodium (5E)-6-oxo-5-[(4-sulfonatophenyl)hydrazinylidene]naphthalene-2-sulfonate (CAS no. 2783-94-0), biodegradation experiment was conducted for 5 days for evaluating the percentage biodegradability of read across substance disodium (5E)-6 -oxo-5 -[(4 -sulfonatophenyl)hydrazinylidene]naphthalene-2 -sulfonate under aerobic conditions. Sewage was used as a test inoculum for the study. The percentage degradation of substance disodium (5E)-6-oxo-5-[(4-sulfonatophenyl)hydrazinylidene]naphthalene-2-sulfonate was determined to be 0% by using BOD parameter in 5 days. Thus, based on percentage degradation, disodium (5E)-6-oxo-5-[(4-sulfonatophenyl)hydrazinylidene]naphthalene-2-sulfonate is considered to be not readily biodegradable in water.

 

On the basis of above results for target chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt(from OECD QSAR toolbox version 3.3, 2017) and for its read across substance (from UERL study report, peer reviewed journals and authoritative database HSDB), it can be concluded that the test substance 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt can be expected to be not readily biodegradable in nature.