Disodium 4-hydroxynaphthalene-2,7-disulphonate

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 prediction was done by using OECD QSAR tool box v3.4

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: Disodium 4-hydroxynaphthalene-2,7-disulphonate
- Common name: 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)
- Molecular formula: C10H6Na2O7S2
- Molecular weight: 348.2624 g/mol
- Smiles notation: c1cc2c(cc1S(=O)(=O)[O-])cc(cc2O)S(=O)(=O)[O-].[Na+].[Na+]
- InChl: 1S/C10H8O7S2.2Na/c11-10-5-8(19(15,16)17)4-6-3-7(18(12,13)14)1-2-9(6)10;;/h1-5,11H,(H,12,13,14)(H,15,16,17);;/q;2*+1/p-2
- Substance type: Organic

Oxygen conditions:

aerobic

Inoculum or test system:

other: Microorganisms

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: % biodegradability (BOD)

Value:

0.629

Sampling time:

28 d

Remarks on result:

other: other details not available

Details on results:

The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter.

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" )  and ("c" and ( not "d") )  )  and ("e" and ( not "f") )  )  and "g" )  and ("h" and ( not "i") )  )  and ("j" and ( not "k") )  )  and ("l" and "m" )  )

Domain logical expression index: "a"

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

Domain logical expression index: "b"

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

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as No alert found by DNA binding by OASIS v.1.4

Domain logical expression index: "d"

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 and Trihydroxybenzenes OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> Amino Anthraquinones OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide and Aminoalkylamine Side Chain OR Non-covalent interaction >> DNA intercalation >> Fused-Ring Primary Aromatic Amines OR Non-covalent interaction >> DNA intercalation >> Quinones and Trihydroxybenzenes OR Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Amino Anthraquinones OR Radical >> Radical mechanism via ROS formation (indirect) >> Fused-Ring Primary Aromatic Amines OR Radical >> Radical mechanism via ROS formation (indirect) >> Quinones and Trihydroxybenzenes OR Radical >> ROS formation after GSH depletion (indirect) OR Radical >> ROS formation after GSH depletion (indirect) >> Quinoneimines OR SN1 OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Amino Anthraquinones OR SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Fused-Ring Primary Aromatic Amines by DNA binding by OASIS v.1.4

Domain logical expression index: "e"

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

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as 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 >> Arenes OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Hydroquinones OR SN1 OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic azo OR SN1 >> Nitrenium Ion formation >> Aromatic nitro OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine by DNA binding by OECD

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 AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols by Protein binding by OASIS v1.4

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.4

Domain logical expression index: "j"

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

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as SNAr OR SNAr >> Nucleophilic aromatic substitution OR SNAr >> Nucleophilic aromatic substitution >> Activated halo-benzenes by Protein binding by OECD

Domain logical expression index: "l"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 206 Da

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 379 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum.

Executive summary:

Biodegradability of target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349 -39 -7) was determined by using OECD QSAR tool box v3.4 with log Kow as primary descriptor. The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)  undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum. On the basis of percent biodegradability value it is concluded that target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

Description of key information

Biodegradability of target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349 -39 -7) was determined by using OECD QSAR tool box v3.4 with log Kow as primary descriptor. The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)  undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum. On the basis of percent biodegradability value it is concluded that target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Predicted data for the target compound2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349-39-7)and supporting weight of evidence studies for its read across substance were reviewed for the biodegradation end point which are summarized as below:

Biodegradability of target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS no. 20349-39-7) was determined by using OECD QSAR tool box v3.4 with log Kow as primary descriptor. The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)  undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum. On the basis of percent biodegradability value it is concluded that target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

Another prediction done by using Estimation Programs Interface Suite (EPI suite, 2017) to estimate the biodegradation potential of the test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349 -39 -7) 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 chemical  2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

In a supporting weight of evidence study done from authoritative database ( J check, 20170 the read across chemical dipotassium 7-hydroxynaphthalene-1, 3-disulfonate (CAS no. 842-18-2) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analysed by using BOD parameter. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 4 weeks of incubation the read across chemical showed 0% biodegradation by BOD parameter so it is concluded that it is not readily biodegradable.

Similarly, in another supporting weight of evidence study done from authoritative database ( J check, 2017) the read across chemical Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate (CAS no. 5460-09-3) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using O2 consumption (BOD), TOC removal and test material analysis by UV vis parameter. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 2 weeks (14 days) read across chemical Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate showed 0% biodegradation by O2 consumption (BOD) parameter, 5 % biodegradation by TOC removal parameter and less than 0 % biodegradation by test material analysis by UV Vis parameter in 14 days. So it is concluded that this read across chemical is not readily biodegradable.

On the basis of results of above mentioned studies for target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349 -39 -7) (from OECD QSAR tool box v3.4 and EPI suite) and supporting weight of evidence study ( from J Check, 2017). It is concluded that the test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) can be expected to be not readily biodegradable.