2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt

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 five closest read across substances, toxicity on daphnia magna was predicted for 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]- 6-sulpho-1-naphthyl]azo]benzene -1,4-disulphonic acid, magnesium sodium salt. Based on the immobility of test organism the EC50 value was estimated to be 686.0 mg/l when 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2- naphthyl]azo]-1-naphthyl] azo]-6-sulpho- 1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1- naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation.  

Toxicity to aquatic algae:

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 2-[[4-[[4-[[6-anilino- 1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]- 6-sulpho-1- naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt. Based on the growth rate inhibition of test organism the EC50 value was estimated to be 863.5 mg/l when 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1 -naphthyl] azo]-6-sulpho- 1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt exposed to Pseudokirchneriella subcapitata for 72 hrs. Based on this value it can be concluded that the substance 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl] azo]-6- sulpho-1-naphthyl]azo]benzene-1,4- disulphonic acid, magnesium sodium salt is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation. 

Additional information

Summarized result of toxicity of 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl] azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) on the mobility, growth and other activity of aquatic invertebrates, algae and cyanobacteria by considering the data for target as well as structurally and functionally similar read across (RA chemical) chemicals studies has been reviewed which are as follows:   

 

Short term toxicity to aquatic invertebrates:

Based on the various prediction data for the target chemical and experimental data for the read across chemical study have been reviewed to determine the toxic nature of 2-[[4-[[4-[[6-anilino-1- hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) on the mobility of aquatic invertebrates. The studies are as mentioned below:  

In the first predicted study for the target chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) from QSAR toolbox 2017, study was carried out. 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 daphnia magna was predicted for 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]- 6-sulpho-1-naphthyl]azo]benzene -1,4-disulphonic acid, magnesium sodium salt. Based on the immobility of test organism the EC50 value was estimated to be 686.0 mg/l when 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2- naphthyl]azo]-1-naphthyl] azo]-6-sulpho- 1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation.  

 

First predicted study was supported by the other experimental study for the read across chemical Brilliant black 1 (2519-30-4) from ABITEC lab report 2016. Aim of the study was to assess the effect of chemical tetrasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo))naphthalene-4,6-disulphonate (Brilliant black 1) on the mobility of daphnia magna. Test was conducted according to OECD Guideline 202. The stock solution 100 mg/l was prepared by dissolving red powder in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. The test substance was tested at the 0, 5, 10, 20, 40, 80, 160 mg/l nominal concentration. Potassium dichromate (K2Cr2O7) were used as a reference positive control. Effects on immobilisation were observed for 48 hours by using nonlinear regression by the software Prism 4.0. After the exposure of chemical for 48 hrs, 50 % immobility was observed. Based on the immobility of daphnia magna, the median effective concentration (EC50) for the test substance, tetrasodium 1-acetamido- 2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo)) naphthalene-4,6-disulphonate (Brilliant black 1), in Daphnia magna was determined to be > 900 mg/L for immobilisation effects. This value indicates that  the substance is likely to be non-hazardous to aquatic invertebrates and cannot be classified as toxic as per the CLP classification criteria.

 

Similarly in the third weight of evidence study for the read across chemical disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate (3567-69-9) from ABITEC report 2016, toxicity study was carried out. Aim of the study was to assess the effect of chemical disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate on the mobility of daphnia magna. Test was conducted according to OECD Guideline 202. The stock solution 150 mg/l was prepared by dissolving dark red powder in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. The test substance was tested at the 0, 0, 10, 45, 67.5, 100, 150 mg/l nominal concentration. Potassium dichromate (K2Cr2O7) were used as a reference positive control. Effects on immobilisation were observed for 48 hours by using nonlinear regression by the software Prism 4.0. After the exposure of chemical for 48 hrs 50 % immobility was observed. Based on the immobility of daphnia magna, the median effective concentration (EC50) for the test substance, disodium 4-hydroxy-3- [(4-sulphonatonaphthyl)azo]naphthalenesulphonate, in Daphnia magna was determined to be 203.2 mg/L for immobilisation effects. This value indicates that the substance is likely to be non-hazardous to aquatic invertebrates and cannot be classified as toxic as per the CLP criteria.

 

Thus based on the predicted data for the target chemical and experimental studies for the read across chemical obtain from various ABITEC lab reports 2016, it was concluded that the chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) was consider as nontoxic and can be consider to be not classified as toxic to aquatic invertebrates as per CLP classification criteria.   

 

Toxicity to aquatic algae:

 

Based on the various prediction data for the target chemical and experimental data for the structurally and functionally similar read across chemical study have been reviewed to determine the toxic nature of 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo] benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) on the growth of aquatic algae and cyanobacteria. The studies are as mentioned below:  

In the first predicted study for the target chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) from QSAR toolbox 2017, study was carried out. 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 2-[[4-[[4-[[6-anilino- 1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]- 6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt. Based on the growth rate inhibition of test organism the EC50 value was estimated to be 863.5 mg/l when 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1 -naphthyl] azo]-6-sulpho- 1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt exposed to Pseudokirchneriella subcapitata for 72 hrs. Based on this value it can be concluded that the substance 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl] azo]-6- sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt is considered to be nontoxic to aquatic environment and cannot classified as per the criteria mentioned in CLP regulation. 

 

First predicted study was supported by the other experimental study for the read across chemical Brilliant black 1 (2519-30-4) from ABITEC lab report 2016. Short term toxicity study of Terasodium 1-acetamido-2-hydroxy-3-(4-((4-sulphonatophenylazo)-7-sulphonato-1-naphthylazo))naphthalene-4,6-disulphonate (Brilliant black 1) to aquatic algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) was conducted for 72 hrs. Test was performed according to the 201 OECD guideline in a static system. 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 and tested at the 0, 12, 20, 35, 60, 100 mg/l nominal concentrations. Effects on the growth rate of the organism were studied. Potassium dichromate (K2Cr2O7) were used as a reference positive control. Effects on growth rate were observed for 72 hours by using nonlinear regression by the software Prism 4.0. Based on the growth rate inhibition of test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the chemical Tetrasodium 1-acetamido-2-hydroxy- 3-(4-((4-sulphonatophenylazo)- 7-sulphonato-1-naphthylazo))naphthalene -4,6-disulphonate (Brilliant black 1), the effect concentration ErC50 was 76.8 mg/l. This value indicates that the substance is likely to be hazardous to aquatic algae and can be classified as aquatic chronic 3 as per the CLP criteria. But as the chemical was readily biodegradable in water so on that basis chemical was consider as nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Similarly in the third weight of evidence study for the read across chemical disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate (3567-69-9) from ABITEC report 2016, toxicity study was carried out. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Disodium 4-hydroxy- 3-[(4-sulphonatonaphthyl)azo] naphthalenesulphonate according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 2.6, 5.6, 12.0, 27.0, 59.0 and 130 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl)azo]naphthalene- sulphonate, in Desmodesmus subspicatus was determined to be 265.1 mg/L. Based on this ErC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance Disodium 4-hydroxy-3-[(4-sulphonatonaphthyl) azo] naphthalenesulphonate does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

 

By considering the another read across chemical (15790-07-5) from UERL lab 2016 which was similar to the target chemical as supports the non-toxic classification of chemical study are as follows. The effect of test item aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex (15790-07-5) 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-[(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/sonication for 30 minutes 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. Care was taken to have a homogeneous solution for the experiment. Test was performed in static manner at proper requirement of pH and temperature. 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 units. After 72 hours of exposure to aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex (15790-07-5) to various nominal test concentration, EC50 calculated from equation through probit analysis was determine to be > 200 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.

 

Thus based on the predicted data for the target chemical and experimental studies for the read across chemical obtain from various ABITEC lab reports 2016 and UERL report, it was concluded that the chemical 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3) was consider as nontoxic and can be consider to be not classified as toxic to aquatic invertebrates as per CLP classification criteria.   

 

On the basis of both studies including invertebrates and algae for the 2-[[4-[[4-[[6-anilino-1-hydroxy-3-sulpho-2-naphthyl]azo]-1-naphthyl]azo]-6-sulpho-1-naphthyl]azo]benzene-1,4-disulphonic acid, magnesium sodium salt (93941-74-3), it was concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.