4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic 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:

QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using the OECD QSAR toolbox version 3.3.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid
- Molecular formula : C18H16N4O12S3
- Molecular weight : 576.538 g/mol
- Smiles notation : O=C(O)C1=NN(C(=O)[C@@H]1\N=N\c1ccc(S(=O)(=O)CCOS(=O)(=O)O)cc1)c1ccc(S(=O)(=O)O)cc1
- InChl : 1S/C18H16N4O12S3/c23-17-15(16(18(24)25)21-22(17)12-3-7-14(8-4-12)36(28,29)30)20-19-11-1-5-13(6-2-11)35(26,27)10-9-34-37(31,32)33/h1-8,15H,9-10H2,(H,24,25)(H,28,29,30)(H,31,32,33)/b20-19+
- Substance type: Organic
- Physical state:

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

Total exposure duration:

72 h

Hardness:

32.1mg/L as Ca CO3

Test temperature:

24.8°C and 28°C

pH:

6.95 and 11.14

Nominal and measured concentrations:

Estimated data

Reference substance (positive control):

not specified

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

24.269 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The EC50 was 24.268 mg/l

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

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

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 Acid moiety OR Amides OR Hydrazines by Aquatic toxicity classification by ECOSAR ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR SN2 OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Alkyl diazo by Protein binding by OECD ONLY

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Schiff base formation OR Schiff base formation >> Pyrazolones and Pyrazolidinones derivatives OR Schiff base formation >> Pyrazolones and Pyrazolidinones derivatives >> Pyrazolones and Pyrazolidinones  by Protein binding by OASIS v1.3 ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as SN1 OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic azo OR SN1 >> Nitrenium Ion formation >> Unsaturated heterocyclic azo by DNA binding by OECD ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Not possible to classify according to these rules (GSH) by Protein binding potency

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Moderately reactive (GSH) OR Moderately reactive (GSH) >> Substituted 1-Alken-3-ones (MA) by Protein binding potency

Domain logical expression index: "h"

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: "i"

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

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Acid moiety AND Amides AND Hydrazines by Aquatic toxicity classification by ECOSAR ONLY

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of log Kow which is >= -5.49

Domain logical expression index: "l"

Parametric boundary:The target chemical should have a value of log Kow which is <= 0.446

Validity criteria fulfilled:

not specified

Conclusions:

Based on the growth rate inhibition of green algae due to the chemical 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid, the EC50 was 24.268 mg/l

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 five closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl] azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid (10149-98-1). Based on the growth rate inhibition of algae, the EC50 value was estimated to be 24.268 mg/l when 4,5-dihydro-5-oxo-4- [[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid exposed toPseudokirchneriella subcapitatafor 72hrs. Based on this value it can be concluded that the substance 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy) ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid is considered to be toxic to aquatic environment and can be classified as aquatic chronic 3 category per the criteria mentioned in CLP regulation. 

    

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 five closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 4,5-dihydro-5-oxo-4- [[4-[[2-(sulphooxy)ethyl] sulphonyl] phenyl] azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid (10149-98-1). Based on the growth rate inhibition of algae, the EC50 value was estimated to be 24.268 mg/l when 4,5-dihydro-5-oxo-4- [[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid exposed to Pseudokirchneriella subcapitata for 72hrs. Based on this value it can be concluded that the substance 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy) ethyl]sulphonyl]phenyl]azo]- 1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid is considered to be toxic to aquatic environment and can be classified as aquatic chronic 3 category per the criteria mentioned in CLP regulation. 

Key value for chemical safety assessment

EC50 for freshwater algae:

24.26 mg/L

Additional information

Various predicted data for the target compound 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl] phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid (10149-98-1) and experimental data for supporting weight of evidence studies for its closest read across substance with log Kow as the primary descriptor and on the basis of structural and functional similarity study were reviewed for the toxicity on the aquatic algae end point which are summarized as below: 

In a prediction done by SSS (2017), based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 4,5-dihydro-5-oxo-4- [[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl] azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid (10149-98-1). Based on the growth rate inhibition of algae, the EC50 value was estimated to be 24.268 mg/l when 4,5-dihydro-5-oxo-4- [[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid exposed to Pseudokirchneriella subcapitata for 72hrs. Based on this value it can be concluded that the substance 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy) ethyl]sulphonyl]phenyl]azo]- 1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid is considered to be toxic to aquatic environment and can be classified as aquatic chronic 3 category per the criteria mentioned in CLP regulation. 

 

First predicted study was supported by the structurally similar read across chemical (12225-21-7) from ABITEC report. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro -1H-pyrazol-4-yl]diazenyl}benzenesulfonate). Test was performed according to OECD Guideline 201. The stock solution 130 mg/l was prepared by dissolving dark yellow powder in OECD growth medium. The test solution was kept for 30 min in ultrasonic bath. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Tested conducted at the concentrations 0, 2.6, 5.6, 12, 27, 59, 130 mg/l. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro -1H-pyrazol-4-yl]diazenyl} benzenesulfonate), in Desmodesmus subspicatus was determined to be 74.2 mg/L on the basis of growth rate inhibition. This value indicates that the substance is likely to be hazardous to aquatic algae and can be classified as aquatic chronic 3 category as per the CLP criteria.

 

Similarly by considering another functional similar RA chemical N,N,N-trimethyl-3-[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl)diazenyl]anilinium chloride (Basic yellow 57) (68391-31-1) from ABITEC report 2016 toxicity was measured. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance N,N,N-trimethyl-3-[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H- pyrazol-4-yl) diazenyl]anilinium chloride (Basic yellow 57) according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 10, 17, 29, 50 and 85 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, N,N,N-trimethyl-3-[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl)diazenyl]anilinium chloride (Basic yellow 57), in Desmodesmus subspicatus was determined to be 67.9 mg/L and also the substance was not rapidly degradable. Thus considering the CLP criteria for aquatic classification of the substance, it is concluded that N,N,N-trimethyl-3-[(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H- pyrazol-4-yl)diazenyl] anilinium chloride (Basic yellow 57) exhibits toxicity to aquatic algae (Desmodesmus subspicatus) in the chronic 3 classification category.

 

In the fourth weight of evidence study from ABITEC report for the read across chemical (2519-30-4) it can be consider that the chemical was toxic to aquatic algae. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo) -7- sulphonato-1 -naphthylazo))naphthalene-4,6-disulphonate. Test was performed according to OECD Guideline 201. The stock solution 100 mg/l was prepared by dissolving black powder in OECD growth medium. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Tested conducted at the nominal concentrations 0, 12, 20, 35, 60, 100 mg/l. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo) -7-sulphonato-1-naphthylazo)) naphthalene- 4,6-disulphonate (2519-30-4) in Desmodesmus subspicatus was determined to be 74.2 mg/L on the basis of growth rate inhibition. This value indicates that the substance is likely to be hazardous to aquatic algae and can be classified as aquatic chronic 3 category as per the CLP classification criteria.

On the basis of above results for target chemical 4,5-dihydro-5-oxo-4-[[4-[[2-(sulphooxy)ethyl]sulphonyl] phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid (10149-98-1) (from OECD QSAR toolbox version 3.3) and for its read across substance from ABITEC reports 2016, it can be concluded that the test substance chemical 4,5-dihydro-5-oxo-4-[[4-[[2- (sulphooxy)ethyl] sulphonyl] phenyl]azo]-1-(4-sulphophenyl)-1H-pyrazole-3-carboxylic acid is toxic to aquatic environment and can classified as aquatic chronic 3 category per the criteria mentioned in CLP regulation.