Sodium 4-(4-(2-hydroxynaphthalenylazo)phenylazo)benzenesulphonate

Endpoint summary

Description of key information

Short-term toxicity to aquatic invertebrates

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 aquatic invertebrate was predicted sodium 4-({4-[(2-hydroxy-1-naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0). EC50 Intoxication value value was estimated to be 135.5442 mg/l for Daphnia magna for 48 hrs duration. It was concluded that sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic invertebrate.

Toxicity to aquatic algae and cyanobacteria

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 aquatic algae was predicted sodium 4-({4-[(2-hydroxy-1-naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0). EC50 growth rate value value was estimated to be 116.059 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic algae.

Additional information

Short-term toxicity to aquatic invertebrates

Following three studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) 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 aquatic invertebrate was predicted sodium 4-({4-[(2-hydroxy-1-naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0). EC50 Intoxication value value was estimated to be 135.5442 mg/l for Daphnia magna for 48 hrs duration. It was concluded that sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic invertebrate.

The above predicted data of 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 ABITEC Lab report 2016, suggests that theDetermination of the inhibition of the mobility of daphnids was carried out with the substancedisodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonateaccording to OECD Guideline 202.

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.

Another supporting experimental study for the structurally similar read across Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate (CAS: 3567-66-6 from the ABITEC Lab report 2016, also suggests that the Determination of the inhibition of the mobility of daphnids was carried out with the substance Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonateaccording to OECD Guideline 202.e.Effects on immobilisation were observed for 48 hours.

The median effective concentration (EC50) for the test substance,Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate, in Daphnia magna was determined to be 100 mg/L on the basis of mobiity inhibition effects in a 48 hour study.

This value indicates that the substance is likely to be non-hazardous to aquatic invertebrates and can be classified as "not classifed" as per the CLP criteria.

Thus based on the effect concentrations which is in the range 100 mg/l to 135.5442 mg/l give the conclusion that test substance sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic inverbrate at environmentally relevant concentrations and can be considered to be “not classified” as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

Following three studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) towards aquatic algae 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 aquatic algae was predicted sodium 4-({4-[(2-hydroxy-1-naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0). EC50 growth rate value value was estimated to be 116.059 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic algae.

The above predicted data of 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 ABITEC Lab report 2016, suggests that the

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substancedisodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonateaccording to OECD Guideline 201.

The test substance was dissolved in DMSO and tested at the concentrations 0, 17, 30, 55, 100 and 185 mg/L. Effects on the growth rate of the organism were studied.

The median effective concentration (EC50) for the test substance,disodium 6-hydroxy-5-[(4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate, in Desmodesmus subspicatus was determined to be 113.2 mg/L.

This value indicates that the substance is not likely to be hazardous to aquatic algae as per the CLP criteria.

Another supporting experimental study for the structurally similar read across Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate (CAS: 3567-66-6 from the ABITEC Lab report 2016, also suggests that the Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substanceDisodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonateaccording to OECD Guideline 201.

The test substance was dissolved in OECD growth medium and tested at the concentrations12.5, 25.0, 50.0, 100.0, 200.0 mg/L. Effects on the growth rate of the organism were studied.

The median effective concentration (EC50) for the test substance, Disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate, in Desmodesmus subspicatus was determined to be 330.2 mg/L on the basis of effects on growth rate in a 72 hour study.

This value indicates that the substance is likely to be non-hazardous to aquatic algae and can be classified as "not classified" as per the CLP criteria.

Thus based on the effect concentrations which is in the range 113.2 mg/l to 330.2 mg/l give the conclusion that test substance sodium 4-({4-[(2-hydroxy-1 naphthyl)diazenyl]phenyl}diazenyl)benzenesulfonate (CAS: 6406-56-0) was likely to be not toxic to aquatic algae at environmentally relevant concentrations and can be considered to be “not classified” as per the CLP classification criteria.