Disodium 8-hydroxynaphthalene-1,6-disulphonate

Endpoint summary

Description of key information

Short term toxicity to aquatic invertebrates:

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on daphnia magna was predicted for disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3). Based on the intoxication of test organism the EC50 value was estimated to be 168.64 mg/l when disodium 8-hydroxy naphthalene-1,6-disulfonate exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance disodium 8-hydroxynaphthalene-1,6-disulfonate is considered to be not toxic to aquatic environment and not classified as per the criteria mentioned in CLP regulation.    

 

Toxicity to aquatic algae and cyanobacteria:

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for disodium 8-hydroxy- naphthalene-1,6-disulfonate (83732-80-3). Based on the growth rate inhibition of algae,the EC50 value was estimated to be 234.47 mg/l when disodium 8-hydroxynaphthalene -1,6-disulfonate exposed to Pseudokirchneriella subcapitata for 72hrs. Based on this value it can be concluded that the substance disodium 8-hydroxynaphthalene-1,6-disulfonate is considered to be not toxic to aquatic environment as per the criteria mentioned in CLP regulation.   

 

Additional information

Summarized result of toxicity of disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) on the growth and other activity of aquatic invertebrates, algae and cyanobacteria by considering the data for target as well as RA chemical which was selected on the basis of structural, functional similarities and log Kow as the primary descriptor are as follows:  

Short term toxicity to aquatic invertebrates:

Various predicted data for the target compound disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) and experimental data for supporting weight of evidence studies for its closest read across substance with log Kow as the primary descriptor and structural, functional similarities were reviewed for the toxicity on the invertebrates 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 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on daphnia magna was predicted for disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3). Based on the intoxication of test organism the EC50 value was estimated to be 168.64 mg/l when disodium 8-hydroxy naphthalene-1,6-disulfonate exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance disodium 8-hydroxynaphthalene-1,6-disulfonate is considered to be not toxic to aquatic environment and not classified as per the criteria mentioned in CLP regulation.    

 

Similarly in a second supporting weight of evidence study from ABITEC report 2016 for read across chemical 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate (3567-66-6), Determination of the inhibition of the mobility of daphnids was carried out with the substance 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate according to OECD Guideline 202. The test substance was tested at the limit concentrations of 100 mg/l for test chemical. Effects on immobilisation were observed for 48 hours. The NOEC 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 mobility inhibition effects in a 48 hour study. This value indicates that the substance 5-amino-4-hydroxy-3-(phenylazo) naphthalene-2,7-disulphonate is likely to be non-hazardous to aquatic invertebrates and cannot be classified as toxic as per the CLP criteria.

 

 

Further first predicted study was supported by the another weight of evidence studies for the structurally similar read across chemical Disodium 3-[(2,4-dimethyl- 5-sulpho- natophenyl) azo]-4-hydroxy naphthalene-1-sulphonate (4548-53-2) from ABITEC report. Determination of the inhibition of the mobility of daphnids was carried out with the substance Disodium 3-[(2,4-dimethyl- 5-sulpho- natophenyl) azo]-4-hydroxy naphthalene-1-sulphonate 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. The median effective concentration (EC50) for the test substance, Disodium 3-[(2,4-dimethyl-5-sulphonatophenyl)azo]- 4-hydroxynaphthalene -1-sulphonate, 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, Disodium 3-[(2,4-dimethyl -5-sulphonatophenyl)azo]- 4-hydroxynaphthalene-1-sulphonate does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna).

 

Similarly in a fourth supporting weight of evidence study from ABITEC report 2016 for read across chemical 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid (130-23-4) toxicity experiment was conducted for evaluating the effect of read across substance on daphnia magna. Determination of the inhibition of the mobility of daphnids was carried out with the substance 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid according to OECD Guideline 202. The test substance was tested at the concentrations of 0 for 3 controls and 5, 10, 25, 100, 200 mg/L for test chemical. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance, 4-amino-5-hydroxynaphthalene -1,7-disulphonic acid, in Daphnia magna was determined to be 500 mg/L for immobilisation effects. This value indicates that the substance 4-amino-5-hydroxynaphthalene -1,7- disulphonic acid 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 from QSAR toolbox version 3.4 for target chemical disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) and also considering experimental K1 data for structurally similar read across chemical from ABITEC lab and UERL lab, it can be concluded that the chemical disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) was nontoxic to the aquatic invertebrates and can be consider to be not classified as toxic as per the CLP classification criteria.

 

Toxicity to aquatic algae and cyanobacteria:

Various predicted data for the target compound disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) and experimental data for supporting weight of evidence studies for its closest read across substance with log Kow as the primary descriptor and structural, functional similarities were reviewed for the toxicity on the aquatic algae and cyanobacteria 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 3.4 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for disodium 8-hydroxy- naphthalene-1,6-disulfonate (83732-80-3). Based on the growth rate inhibition of algae,the EC50 value was estimated to be 234.47 mg/l when disodium 8-hydroxynaphthalene -1,6-disulfonate exposed to Pseudokirchneriella subcapitata for 72hrs. Based on this value it can be concluded that the substance disodium 8-hydroxynaphthalene-1,6-disulfonate is considered to be not toxic to aquatic environment as per the criteria mentioned in CLP regulation.   

 

Similarly in a second supporting weight of evidence study from ABITEC report 2016 for read across chemical 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate (3567-66-6), Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene -2,7-disulphonate according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 0, 12.5, 25, 100, 200 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) 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. Based on this ErC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance disodium 5-amino-4-hydroxy-3-(phenylazo) naphthalene- 2,7-disulphonate does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus) and not classified as toxic as per the CLP classification criteria. 

 

Further first predicted study was supported by the another weight of evidence studies for the structurally similar read across chemical Disodium 3-[(2,4-dimethyl- 5-sulpho- natophenyl) azo]-4-hydroxy naphthalene-1-sulphonate (4548-53-2) from ABITEC report. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Disodium 3-[(2,4-dimethyl -5-sulphonatophenyl) azo]-4-hydroxynaphthalene -1-sulphonate according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 0, 12.5, 25, 50, 100 and 200 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, Disodium 3-[(2,4-dimethyl-5-sulphonatophenyl)azo]- 4-hydro xynaphthalene-1-sulphonate, in Desmodesmus subspicatus was determined to be 276.1 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 3-[(2,4-dimethyl-5-sulphonatophenyl) azo]-4-hydroxynaphthalene-1-sulphonate does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

 

Similarly by considering data for supporting weight of evidence study from ABITEC report 2016 for read across chemical 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid (130-23-4) toxicity experiment was conducted for evaluating the effect of read across substance. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 2.2, 11, 25, 55 and 120 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, 4-amino- 5-hydroxynaphthalene-1,7-disulphonic acid, in Desmodesmus subspicatus was determined to be 129.4 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 4-amino-5-hydroxynaphthalene-1,7-disulphonic acid does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus) and not classified as toxic as per the CLP classification criteria.

 

Similarly for the same read across chemical, toxicity study was conducted on algae and reported from UERL lab, 2016, The effect of test item 4-amino-5-hydroxynaphthalene-1,7- disulphonic acid, CAS No. 130-23-4 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 and 200mg/l. The test concentrations were prepared using stock solution of the test item using mineral media. 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 >200mg/l. Thus, based on the EC50 value, test substance 4-amino-5-hydroxynaphthalene -1,7-disulphonic acid can be classified as not hazardous and nontoxic as per the criteria of CLP regulation.

 

Thus based on the predicted data from QSAR toolbox version 3.4 for target chemical disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) and also considering experimental K1 data for structurally and functionally similar read across chemical from ABITEC lab and UERL lab, it can be concluded that the chemical disodium 8-hydroxynaphthalene-1,6-disulfonate (83732-80-3) was nontoxic to the aquatic algae and cyanobacteria and can be consider to be not classified as toxic as per the CLP classification criteria.

 

Thus based on the toxicity results for both invertebrates and algae chemical was consider as nontoxic and can be consider to be not classified as per the CLP classification criteria.