Disodium 4-hydroxynaphthalene-2,7-disulphonate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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:

Data is from OECD QSAR toolbox version.3.3 and QMRF report has been attached.

Qualifier:

according to guideline

Guideline:

other: Predicted data

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.3 with log kow as the primary discriptors.

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

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

163.785 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

other: Intoxication

Remarks on result:

other: not toxic

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((("a" or "b" )  and ("c" and ( not "d") )  )  and "e" )  and ("f" and "g" )  )

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 Not possible to classify according to these rules by DPRA Cysteine peptide depletion

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as High reactive OR High reactive >> Activated haloarenes OR Low reactive OR Low reactive >> N-substituted aromatic amides by DPRA Cysteine peptide depletion

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Class 5 (Not possible to classify according to these rules) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "f"

Parametric boundary:The target chemical should have a value of Koc (Log Kow) which is >= 0.0664 L/kg

Domain logical expression index: "g"

Parametric boundary:The target chemical should have a value of Koc (Log Kow) which is <= 3.66 L/kg

Conclusions:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity to invertebrate was predicted 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7). Intoxication value was estimated to be 163.785 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) was likely to be not toxic to aquatic invertebrate.

Executive summary:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity to invertebrate was predicted 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7). Intoxication value was estimated to be 163.785 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) was likely to be not toxic to aquatic invertebrate.

 

Description of key information

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary

descriptor and considering the closest read across substances, the toxicity to invertebrate was predicted 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7). Intoxication value was estimated to be 163.785 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) was likely to be not toxic to aquatic invertebrate.

 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

163.785 mg/L

Additional information

Following studies include the predicted data and experimental study for the target chemical and structurally similar read across to conclude the toxicity extent of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) towards aquatic invertebrate is summarized as follows:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary

descriptor and considering the closest read across substances, the toxicity to invertebrate was predicted 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7). Intoxication value was estimated to be 163.785 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) was likely to be not toxic to aquatic invertebrate.

The predicted for the target chemical is supported by the experimental study of structurally similar read across disodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate (CAS: 2783 -94 -0) from the standard experimental report ABITEC 2016, suggests that the

Determination of the inhibition of the mobility of daphnids was carried out with the substance disodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate according to OECD Guideline 202 for 48 hr under static condition.

The test substance was tested at the concentration 100 mg/L. 0% Daphnia were immobilised at the end of the test.

The median effective concentration (EC50) for the test substance,disodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate, in Daphnia magna was determined to be > 100 mg/L for immobilisation effects.This value indicates that the substance is not likely to be hazardous to aquatic invertebrates as per the CLP criteria and is "not classified" .

Further it is supported by the another structurally similar read across disodium 5-acetamido-4-hydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonate (CAS: 3734-67-6) study from ABITEC 2016, also suggests that An acute immobilisation test was used to test how a range of concentrations of CAS 3734-67-6 exerts different degrees of toxic effects on the swimming capability of Daphnia magna under otherwise identical test conditions. The test was performed in close resemblance to OECD guideline 202 by ABITEC in Prague. The standardized protocol used to obtain the herein described results was by the testing laboratory referred to as“CSN EN ISO 6341”. The testing aim was to determine a EC50 after 48 hours of exposure to D. magna. Daphnids were exposed to CAS 3734-67-6 in 50 ml beakers in a volume of 25 ml of liquid solution containing both the chemical and media as specified in OECD 202. The beakers were placed in a temperature controlled room at 20±1 degrees Celsius. TheD. magna(age≤24) used for the test had been breed at ABITEC. The breeding stock ofD. magnaoriginated from University of Technology in Prague. The animals were exposed to medium (i.e.a beaker containing only medium) and/or the tested chemical during 48 hours (±1 hour). None of the exposed animal’s immobilization were affected by exposure to only medium. The nominal concentrations used were: 100 mg/L (limit test). There were 5 Daphnia per test vessels and 4 replicates per concentration. The pH in test vessels were 7.7-7.8 mg/L. The positive control/reference substance used in the tested showed an expected result and gave an EC50 that corresponded to previous exposures with this chemical in D. magna. The EC50 was defined as a concentration that immobilizes 50% of the exposed D. magna. Eight percent of immobilization in D. magna after 48 hours of exposure to 100 mg/L of CAS 3734-67-6 was observed. The EC8 was therefore estimated to be 100 mg/L.

Thus based on the effect concentrations which is in the range 100 mg/L to 163.785 mg/l give the conclusion that test substance 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS: 20349-39-7) was likely to be not toxic to aquatic invertebrate at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be“not classified”as per the CLP classification criteria.