p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonic acid

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 invertebrate was predicted 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0). EC50 Intoxication value was estimated to be 390.289 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) was likely to be not toxic to 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 algae was predicted 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0). EC50 growth rate value was estimated to be 398.494 mg/l for Desmodesmus subspicatus for 72 hrs duration. It was concluded that 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) was likely to be not toxic to algae.

Additional information

Short-term toxicity to aquatic invertebrates

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) towards 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 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0). EC50 Intoxication value was estimated to be 390.289 mg/l for Daphnia magna for 48 hrs duration. It was concluded that 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) was likely to be not toxic to invertebrate.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across Aluminium,6-hydroxy-5- [(2-methoxy-5-methyl-4-sul fophenyl)azo ]-2-naphthalenesulfonic acid complex (CAS: 68583-95-9) from the ABITEC lab 2016, suggests that theDetermination of the inhibition of the mobility of daphnids was carried out with the substance Aluminium,6-hydroxy-5- [(2-methoxy-5-methyl-4-sul fophenyl)azo ]-2-naphthalenesulfonic acid complex according to OECD Guideline 202.

A limit test at sample concentration of 100 mg/L was performed. Effects on immobilisation were observed for 48 hours. At 100 mg/l only 8% inhibition was observed, thus it can be concluded that the EC50 was >100 mg/l.

The median effective concentration (EC50) for the test substance, Aluminium, 6-hydroxy-5- [(2-methoxy-5-methyl-4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex, in Daphnia magna was determined to be >100 mg/L for immobilisation effects. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance, Aluminium, 6-hydroxy-5- [(2-methoxy-5-methyl-4-sulfophenyl)azo ]-2-naphthalenesulfonic acid complex does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna).

Another supporting experimental study for the structurally similar read across 2,7-Naphthalenedisulfonic acid, 3-hydroxy-4-[(4-sulfo-1-naphthalenyl), sodium salt; Amaranth dye; trisodium 3-hydroxy-4-[(4-sulfonato-1-naphthyl)diazenyl]naphthalene-2,7-disulfonate (CAS: 915-67-3) from the ABITEC lab 2016, also suggests that theDetermination of the inhibition of the mobility of daphnids was carried out with the substance 2,7-Naphthalenedisulfonic acid, 3-hydroxy- 4-[(4-sulfo-1-naphthalenyl), sodium salt; Amaranth dye according to OECD Guideline 202.

The limit test wasperformed at 100 mg/l. Effects on immobilisation were observed for 48 hours.

The effective concentration (EC8) for the test substance, 2,7-Naphthalenedisulfonic acid, 3-hydroxy-4- [(4-sulfo-1 -naphthalenyl), sodium salt (Amaranth dye), 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 not be classified as toxic as per the CLP criteria.

Thus based on the effect concentrations which is in the range > 100 mg/l to 390.289 mg/l give the conclusion that test substance 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) was likely to be not toxic to aquatic invertebrate 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 studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) towards 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 algae was predicted 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0). EC50 growth rate value was estimated to be 398.494 mg/l for Desmodesmus subspicatus for 72 hrs duration. It was concluded that 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) was likely to be not toxic to algae.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across Aluminium,6-hydroxy-5- [(2-methoxy-5-methyl-4-sul fophenyl)azo ]-2-naphthalenesulfonic acid complex (CAS: 68583-95-9) from the UERL lab 2016, suggests that theeffect of test item aluminium, 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex, CAS No. 68583-95-9 was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 6.25mg/L, 12.5mg/L, 25mg/L, 50mg/L, 100mg/L, 200mg/L. The test solution was prepared in aseptic condition. The test item aluminium, 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)azo]- 2-naphthalenesulfonic acid complex was prepared by adding 50 mg of test item in 250 ml of BBM to get the final concentration of 200 mg/L. This stock solution was kept for stirring for 24 hours and filter it to obtain a homogenous solution for the experiment. The test concentrations were chosen according to the available data of the test item. The concentrations chosen were set up to the water solubility limit. The remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial of the culture was kept 1 X 104cells/ml.

The microscopic observations were noted down in each of the control vessel. All the cells appeared healthy, round and green throughout the study duration in the control. Also, the drift in pH in the control vessels did not increase by >1.5 units when observed on 72 hours as compared to 0 hours. The average pH drift observed in the control vessels was 0.1 units.The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 136.57 mg/L.

Based on the EC50, it can be concluded that the chemical was nontoxic and can be consider to be not classified as toxic as per the CLP classification criteria.

Another supporting experimental study for the structurally similar read across 2,7-Naphthalenedisulfonic acid, 3-hydroxy-4-[(4-sulfo-1-naphthalenyl), sodium salt; Amaranth dye; trisodium 3-hydroxy-4-[(4-sulfonato-1-naphthyl)diazenyl]naphthalene-2,7-disulfonate (CAS: 915-67-3) from the ABITEC lab 2016, also suggests that theFreshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 2,7-Naphthalenedi- sulfonic acid, 3-hydroxy-4-[(4-sulfo- 1-naphthal - enyl), sodium salt (Amaranth dye) according to OECD Guideline 201.

The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 12.5, 25, 50, 100, 200 mg/L. Effects on the growth rate of the organism were studied.

The median effective concentration (ErC50) for the test substance, 2,7-Naphthalenedisulfonic acid, 3-hydroxy-4-[(4-sulfo-1- -naphthalenyl), sodium salt, in Desmodesmus subspicatus was determined to be 356.2 mg/L.

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

Thus based on the effect concentrations which is in the range 136.57 mg/l to 398.494 mg/l give the conclusion that test substance 4-{4-[(2-methoxy-5-methyl-4-{[2-(sulfooxy)ethyl]sulfonyl}phenyl)diazenyl]-3-methyl-5-oxo-4,5-dihydro... (CAS: 60958-41-0) 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.