4,4'-dihydroxy-7,7'-iminodi(naphthalene-2-sulphonic acid)

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 3.4 with logKow as the primary descriptor.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid
- Molecular formula: C20H15NO8S2
- Molecular weight: 461.47 g/mol
- Smiles notation: O=S(=O)(O)c1cc(O)c2c(cc(Nc3ccc4c(cc(S(=O)(=O)O)cc4O)c3)cc2)c1
- InChl: 1S/C20H15NO8S2/c22-19-9-15(30(24,25)26)7-11-5-13(1-3-17(11)19)21-14-2-4-18-12(6-14)8-16(10-20(18)23)31(27,28)29/h1-10,21-23H,(H,24,25,26)(H,27,28,29)
- Substance type: Organic
- Physical state: Solid

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:

0.5

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

Test substance undergoes 0.5% 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 6 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" or "b" or "c" or "d" )  and "e" )  and "f" )  and "g" )  and "h" )  and ("i" and "j" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Very strong binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> N-Substituted Aromatic Amines AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Class 2 (less inert compounds) by Acute aquatic toxicity classification by Verhaar (Modified)

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Acid moiety AND Phenols, Poly by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as days - weeks by Biodeg primary (Biowin 4) 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 Not calculated by Hydrolysis half-life (pH 6.5-7.4) ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Reactive unspecified by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "i"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 171 Da

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 549 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test chemical 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid was estimated to be not readily biodegradable in water.

Executive summary:

Biodegradability of 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid (CAS no. 87 -03 -6) is predicted using OECD QSAR toolbox version 3.4 with logKow as the primary descriptor. Test substance undergoes 0.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphthalen-2 -yl)amino]naphthalene-2-sulfonic acid was estimated to be not readily biodegradable in water.

Description of key information

Biodegradability of 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid (CAS no. 87 -03 -6) is predicted using OECD QSAR toolbox version 3.4 (2017) with logKow as the primary descriptor. Test substance undergoes 0.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphthalen-2 -yl)amino]naphthalene-2-sulfonic acid 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

Various predicted data for the target compound 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid(CAS No. 87-03-6) and supporting weight of evidence studies for its read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a predicted data done by SSS (2017) using OECD QSAR toolbox version 3.4 with logKow as the primary descriptor, percentage biodegradability of test chemical 4-hydroxy-7-[(5- hydroxy-7 -sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid(CAS No. 87-03-6) was estimated.Test substance undergoes 0.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphthalen-2 -yl)amino]naphthalene-2-sulfonic acid was estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphtha len-2 -yl)amino]naphthalene-2 -sulfonic acid(CAS No. 87-03-6) 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 chemical 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphthalen-2 -yl)amino]naphthalene-2 -sulfonic acid is expected to be not readily biodegradable.

 

In a supporting weight of evidence study from peer reviewed journal (U. Pagga and O. Brown; 1986) for the read across chemical Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl] -4,4'-diyl)bis(azo)]bis[4,5-dihydroxynaphthalene-2,7-disulphonate] (CAS no. 4198-19-0), biodegradation experiment was carried out for 42 days for evaluating the percentage biodegradation of the read across chemical Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl]-4,4'-diyl)bis(azo) ]bis[4,5 -dihydroxynaphthalene-2,7 -disulphonate] 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 the test substance Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl] -4,4'-diyl)bis(azo)]bis[4,5 -dihydroxynaphthalene-2,7 -disulphonate] was determined to be -17% by using DOC removal parameter in 42 days. Thus, based on percentage degradation, the chemical Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[4,5-dihydroxy naphthalene-2,7-disulphonate] was considered to be not readily biodegradable in nature.

 

For the read across chemical disodium 7-amino-4-hydroxy-3-[(E)-2-(4-{4-[(E)-2-(1-hydroxy-4-sulfonatonaphthalen-2-yl)diazen-1-yl]-3-methoxyphenyl}-2-methoxyphenyl)diazen-1 -yl]naphthalene-2-sulfonate (CAS no. 6449-35-0), biodegradation study was carried out for 42 days for evaluating the percentage biodegradation of the read across chemical disodium 7 -amino-4 -hydroxy-3 -[(E)-2 -(4 -{4 -[(E)-2 -(1 -hydroxy-4 -sulfonatonaphthalen-2 -yl)diazen-1 -yl]-3 -methoxyphenyl}-2 -methoxyphenyl)diazen-1 -yl]naphthalene-2-sulfonate using modified OECD Guideline 302B (U. Pagga and O. Brown; 1986). 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 the test substance disodium 7 -amino-4 -hydroxy-3 -[(E)-2 -(4 -{4 -[(E)-2 -(1 -hydroxy-4 -sulfonatonaphthalen-2 -yl)diazen-1 -yl]-3 -methoxyphenyl}-2 -methoxyphenyl)diazen-1 -yl]naphthalene-2 -sulfonate was determined to be 44% by using DOC removal parameter in 42 days. Thus, based on percentage degradation, the chemical disodium 7 -amino-4 -hydroxy-3 -[(E)-2 -(4 -{4 -[(E)-2 -(1 -hydroxy-4 -sulfonatonaphthalen-2 -yl)diazen-1 -yl]-3 -methoxyphenyl}-2 -methoxyphenyl)diazen-1 -yl]naphthalene-2 -sulfonate was considered to be not readily biodegradable in nature.

In a supporting weight of evidence study from authoritative database (J-CHECK, 2017) for the read across chemical disodium 4-hydroxy-7-{[(5-hydroxy-7-sulfonato-2-naphthyl)carba moyl]amino}naphthalene-2-sulfonate (CAS no. 20324-87-2), biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of read across substance disodium 4 -hydroxy-7 -{[(5 -hydroxy-7 -sulfonato-2 -naphthyl)carbamoyl]amino}naphthalene-2 -sulfonate. 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 substance disodium 4 -hydroxy-7 -{[(5 -hydroxy-7 -sulfonato-2 -naphthyl) carbamoyl]amino}naphthalene-2 -sulfonate was determined to be 0 and 1.3% by BOD and TOC removal parameter in 14 days. Thus, based on percentage degradation, disodium 4 -hydroxy-7 -{[(5 -hydroxy-7 -sulfonato-2 -naphthyl)carbamoyl]amino}naphthalene-2 -sulfonate is considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl] -4,4'-diyl)bis(azo) ]bis[5 -amino-4 -hydroxynaphthalene-2,7 -disulphonate] (CAS no. 2429 -74 -5) (J-CHECK and HSDB, 2017). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) under aerobic conditions. 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 substance Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[5-amino-4-hydroxy naphthalene-2,7-disulphonate] was determined to be 4, 1 and 2% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, Tetrasodium 3,3'-[(3,3'-dimethoxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)] bis[5-amino-4-hydroxynaphthalene-2,7-disulphonate] is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical 4-hydroxy-7-[(5-hydroxy-7-sulfonaphthalen-2-yl)amino]naphthalene-2-sulfonic acid(from OECD QSAR toolbox version 3.4 and EPI suite, 2017) and for its read across substance (from peer reviewed journal and authoritative databases J-CHECK & HSDB), it can be concluded that the test substance 4 -hydroxy-7 -[(5 -hydroxy-7 -sulfonaphthalen-2 -yl)amino]naphthalene-2 -sulfonic acid can be expected to be not readily biodegradable in nature.