Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate

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 Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6). Based on the intoxication of test organism the EC50 value was estimated to be 170 mg/l when Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate exposed to daphnia magna for 48 hrs.        

Based on this value it can be concluded that the substance Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonateis 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 seven closest read across substances, toxicity on Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) predicted for Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6). The EC50 value was estimated to be 144.5 mg/l when Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate exposed to Desmodesmus subspicatus for 72 hrs. Based on this value it can be concluded that the substance Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl) phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) is considered to be not toxic to aquatic environment and not classified as per the criteria mentioned in CLP regulation.   

 

Additional information

Summarized result of toxicity of Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) on the 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) 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 Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) on the growth of invertebrates. The studies are as mentioned below: 

In the first predicted study for the target chemical Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl) phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) 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 Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6). Based on the intoxication of test organism the EC50 value was estimated to be 170 mg/l when Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate exposed to daphnia magna for 48 hrs.        

Based on this value it can be concluded that the substance Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonateis 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 (3734-67-6) from ABITEC lab report. An acute immobilisation test was used to test how a range of concentrations of Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate exerts different degrees of toxic effects on the swimming capability of Daphnia magna under otherwise identical test conditions. The test was performed in close resemblance to OECD guideline 202 by ABITEC in Prague. The testing aim was to determine a EC50 after 48 hours of exposure to D. magna. Daphnids were exposed to Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate in 50 ml beakers in a volume of 25 ml of liquid solution containing both the chemical and media as specified in OECD 202. The beakers were placed in a temperature controlled room at 20±1 degrees Celsius. The D. magna (age ≤24) used for the test had been breed at ABITEC. The breeding stock of D. Magna originated from University of Technology in Prague. The animals were exposed to medium (i.e. a beaker containing only medium) and/or the tested chemical during 48 hours (±1 hour). None of the exposed animal’s immobilization were affected by exposure to only medium. The nominal concentrations used were: 100 mg/L (limit test). There were 5 Daphnia per test vessels and 5 replicates per concentration. The pH in test vessels were 7.7-7.8 mg/L. The positive control/reference substance used in the tested showed an expected result and gave an EC50 that corresponded to previous exposures with this chemical in D. magna. The IC50 was defined as a concentration that immobilizes 50% of the exposed D. magna. Eight percent immobilization in D. magna was observed after 48 hours of exposure to 100 mg/L of Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate. The IC8 was therefore estimated to be 100 mg/L. Based on the IC8, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per CLP classification criteria.

 

Similarly in the third weight of evidence study for the read across chemical Amaranth dye (915-67-3) from ABITEC report, toxicity study was carried out. Determination 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 was performed 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 mobility inhibition effects in a 48 hour study. 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.

 

 

Based on the predicted data for the target chemical and experimental studies for the read across chemical obtain from various sources (Chemosphere, j-check, 2017) toxicity on invertebrates was studied due to the exposure of Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6), it was concluded that the chemical Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate 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 read across chemical study have been reviewed to determine the toxic nature of Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) on the growth of aquatic algae. The studies are as mentioned below: 

In the first predicted study for the target chemical Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl) phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) 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 seven closest read across substances, toxicity on Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) predicted for Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6). The EC50 value was estimated to be 144.5 mg/l when Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate exposed to Desmodesmus subspicatus for 72 hrs. Based on this value it can be concluded that the substance Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl) phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) is considered to be not toxic to aquatic environment and not classified as per the criteria mentioned in CLP regulation.   

 

First predicted study was supported by the other experimental study for the read across chemical (3734-67-6) from ABITEC lab report. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7- disulphonate according to OECD Guideline 201. The stock solution 100 mg/l was prepared by dissolving red powder in OECD growth medium. The solution was kept 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. 5x10(3) cells /ml algal culture were use in the study for total exposure period of 72hrs. Test conducted in 50 ml glass vessel filled with 50 ml of sample volume and tested at the concentrations 0, 0, 20, 30, 45, 67, 100 mg/l. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate, in Desmodesmus subspicatus was determined to be 285.8 mg/L. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as toxic as per the CLP criteria.

 

Similarly in the third weight of evidence study for the same read across chemical from UERL lab report 2016 study has been carried. Aim of this study was to determine the effect of test substance disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate (3734 -67 -6) 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,12.5 mg/L,25 mg/L,50 mg/L,100 mg/L,200 mg/L. The test substance 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 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 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 test substance. The microscopic observations were also noted in each of the experimental flasks. All the cells appeared healthy, round and green throughout the test duration in the control and in the experimental flask also, no significant changes were observed. The EC50 calculated from equation through probit analysis on the basis of growth rate inhibition was observed to be 160.76 mg/L. Thus 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.

 

The fourth study from ABITEC lab consider for the read across chemical (915-67-3) as it is similar to the target chemical and also supports the nature of chemical. Freshwater 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 stock solution (200 g/L) was prepared by dissolving brown 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. 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 cannot be classified as toxic as per the CLP criteria.

 

 

Based on the predicted data for the target chemical and experimental studies for the read across chemical obtain from various sources (ABITEC and UERL lab report) toxicity on algae was studied and it was concluded that the chemical Sodium 6-amino-5-[[4-chloro-2-(trifluoromethyl)phenyl]azo]-4-hydroxynaphthalene-2-sulphonate (57741-47-6) was consider as nontoxic and can be consider to be not classified as toxic to aquatic invertebrates as per CLP classification criteria.