7-acetamido-4-hydroxy-3-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2-sulphonic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

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 the test material: 7-acetamido-4-hydroxy-3-[(E)-2-{4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]naphthalene-2-sulfonic acid
- IUPAC name: 7-acetamido-4-hydroxy-3-[(E)-2-{4-[2-(sulfooxy)ethanesulfonyl]phenyl}diazen-1-yl]naphthalene-2-sulfonic acid
- Molecular formula: C20H19N3O11S3
- Molecular weight: 573.578 g/mol
- Smiles: c1c(c(c(c2ccc(cc12)NC(=O)C)O)\N=N\c1ccc(cc1)S(=O)(=O)CCOS(=O)(=O)O)S(=O)(=O)O
-InChI:1S/C20H19N3O11S3/c1-12(24)21-15-4-7-17-13(10-15)11-18(36(28,29)30)19(20(17)25)23-22-14-2-5-16(6-3-14)35(26,27)9-8-34-37(31,32)33/h2-7,10-11,25H,8-9H2,1H3,(H,21,24)(H,28,29,30)(H,31,32,33)/b23-22+
- Substance type: Organic
- Physical state: Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

300.026 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

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

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Vinyl Sulfones by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Ester aminolysis AND Acylation >> Ester aminolysis >> Amides by Protein binding by OASIS v1.3

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Direct Acylation Involving a Leaving group AND Acylation >> Direct Acylation Involving a Leaving group >> Acetates by Protein binding by OECD

Domain logical expression index: "d"

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

Domain logical expression index: "e"

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

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as AN2 OR AN2 >> Michael-type addition on alpha, beta-unsaturated carbonyl compounds OR AN2 >> Michael-type addition on alpha, beta-unsaturated carbonyl compounds >> Four- and Five-Membered Lactones OR AN2 >> Shiff base formation after aldehyde release OR AN2 >> Shiff base formation after aldehyde release >> Specific Acetate Esters OR Non-covalent interaction OR Non-covalent interaction >> DNA intercalation OR Non-covalent interaction >> DNA intercalation >> DNA Intercalators with Carboxamide Side Chain OR Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitroarenes with Other Active Groups OR SN1 OR SN1 >> Alkylation after metabolically formed carbenium ion species OR SN1 >> Alkylation after metabolically formed carbenium ion species >> Polycyclic Aromatic Hydrocarbon Derivatives OR SN1 >> Nucleophilic attack after carbenium ion formation OR SN1 >> Nucleophilic attack after carbenium ion formation >> Specific Acetate Esters OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation OR SN1 >> Nucleophilic attack after diazonium or carbenium ion formation >> Nitroarenes with Other Active Groups OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroarenes with Other Active Groups OR SN2 OR SN2 >> Acylation OR SN2 >> Acylation >> Specific Acetate Esters OR SN2 >> Alkylation, direct acting epoxides and related OR SN2 >> Alkylation, direct acting epoxides and related >> Epoxides and Aziridines OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation OR SN2 >> Alkylation, direct acting epoxides and related after P450-mediated metabolic activation >> Polycyclic Aromatic Hydrocarbon Derivatives OR SN2 >> Alkylation, ring opening SN2 reaction OR SN2 >> Alkylation, ring opening SN2 reaction >> Four- and Five-Membered Lactones OR SN2 >> Nucleophilic substitution at sp3 Carbon atom OR SN2 >> Nucleophilic substitution at sp3 Carbon atom >> Specific Acetate Esters OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 OR SN2 >> SN2 attack on activated carbon Csp3 or Csp2 >> Nitroarenes with Other Active Groups by DNA binding by OASIS v.1.3

Domain logical expression index: "g"

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

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Direct Acylation Involving a Leaving group AND Acylation >> Direct Acylation Involving a Leaving group >> Acetates by Protein binding by OECD

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Acylation >> Direct Acylation Involving a Leaving group >> Azlactone OR Michael addition OR Michael addition >> Acid imides OR Michael addition >> Acid imides >> Acid imides-MA OR No alert found by Protein binding by OECD

Domain logical expression index: "j"

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: "k"

Referential boundary: The target chemical should be classified as Aromatic compound AND Azo compound AND Carbonic acid derivative AND Carboxylic acid amide AND Carboxylic acid derivative AND Carboxylic acid sec. amide AND Hydroxy compound AND Phenol AND Sulfonic acid AND Sulfonic acid derivative AND Sulfuric acid derivative AND Sulfuric acid monoester by Organic functional groups, Norbert Haider (checkmol) ONLY

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Aromatic compound AND Azo compound AND Carbonic acid derivative AND Carboxylic acid amide AND Carboxylic acid derivative AND Carboxylic acid sec. amide AND Hydroxy compound AND Phenol AND Sulfonic acid AND Sulfonic acid derivative AND Sulfuric acid derivative AND Sulfuric acid monoester by Organic functional groups, Norbert Haider (checkmol) ONLY

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of log Kow which is >= -7.06

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of log Kow which is <= 0.307

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 algae was predicted 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9). Growth rate value was estimated to be 300.026 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) was likely to be not toxic to aquatic algae.

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 algae was predicted 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9). Growth rate value was estimated to be 300.026  mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) was likely to be not toxic to aquatic algae.

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 algae was predicted 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9). Growth rate value was estimated to be 300.026  mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) was likely to be not toxic to aquatic algae.

Key value for chemical safety assessment

EC50 for freshwater algae:

300.026 mg/L

Additional information

Following studies include predicted data and the experimental studies for the structurally similar read across to conclude the toxicity extent of 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) 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 algae was predicted 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9). Growth rate value was estimated to be 300.026  mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 7-acetamido-4-hydroxy-3-[(4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) was likely to be not toxic to aquatic algae.

The predicted data for the target chemical is supported by the experimental study of structurally similar read across disodium 5-acetamido-4-hydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonate (CAS: 3734 -67 -6) from ABITEC reports suggests that A freshwater algal growth inhibition exposure assessment was used to test how a range of concentrations of CAS 3734-67-6 exerts different degrees of toxic effects on the growth of Desmodesmus subspicatusunder otherwise identical test conditions. The test was performed in close resemblance to OECD guideline 201 by ABITEC in Prague, Crez Republic. The standardized protocol used to obtain the herein described results was by the testing laboratory referred to as “CSN EN ISO 8692”. The 72 hours EC50 was by the testing laboratory defined as the concentration estimated to inhibit 50 per cent of the algae cell growth compared to unexposed cells after 27 hours of exposure. The nominal concentrations used for the exposure assessment were as follows:0, 20, 30, 45, 67 and 100 mg/L. The positive control/reference substance used in the tested showed an expected result and gave a EC50 that corresponded to previous exposures with this chemical in Desmodesmus subspicatus.In conclusion, the EC50 for CAS 3734-67-6 was 285.8 mg/L (95% C.I.: 173.5-470.8 mg/L) after 72 hours of exposure.It can be concluded fom the value that the disodium 5-acetamido-4-hydroxy-3-(phenyldiazenyl)naphthalene-2,7-disulfonate is not toxic to aquatic algae and can be considered as "not classified" as per the classification criteria for aquatic environment.

Another exeprimental study of structurally similar read across 1,2-dihydropyridazine-3,6-dione, monopotassium salt (CAS: 28382 -15 -2) from U.S. Environmental Protection Agency 1992, also suggests that the Toxicity to aquatic algae and cyanobacteria test as carried out for 1,2-dihydropyridazine-3,6-dione, monopotassium salt for 5 days to study the effects on aquatic algae. Population (Abundance) was measured during the test. The study was carried out with 309 Skeletonema costatum

(Diatom) in saltwater under static condition. The Effective concentration EC50 to 50% of Skeletonema costatum for 1,2-dihydropyridazine-3,6-dione, monopotassium salt in 5 days is 102 mg/L. It can be concluded from the value that the 1,2-dihydropyridazine-3,6-dione, monopotassium salt is not toxic to the aquatic algae and can be considered as “not classified” as per the classification criteria for aquatic environment.

Thus based on the effect concentrations which is in range of 102 mg/l to 300.026 mg/L gives the conclusion that test substance 7-acetamido-4-hydroxy-3-[(4-{[2 (sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2-sulfonic acid (CAS: 68189-39-9) was likely to be not toxic to algae at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be“not classified”as per the CLP classification criteria for aquatic environment.