Trisodium 4-[[1-hydroxy-6-[[[[5-hydroxy-6-(phenylazo)-7-sulphonato-2-naphthyl]amino]carbonyl]amino]-3-sulphonato-2-naphthyl]azo]benzoate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

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, gene mutation was predicted for Trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen -2-yl}carbamoyl)amino]-3- sulfonatonaphthalen-2-yl} diazen-1-yl] benzoate. The study assumed the use of Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 with S9 metabolic activation system. Trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl] -7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3- sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate was predicted to not induce gene mutation in Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 in the presence of S9 metabolic activation system and hence, according to the prediction made, it is not likely to classify as a gene mutant in vitro.

Based on the predicted result it can be concluded that the substance is considered to be not toxic as per the criteria mentioned in CLP regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Gene mutation in vitro:

Prediction model based estimation and data from read across chemicals have been reviewed to determine the mutagenic nature of 4-[(E)-2 -{1-hydroxy-6-

[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3-sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate. The smmary is as mentioned below:

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, gene mutation was predicted for Trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen -2-yl}carbamoyl)amino]-3- sulfonatonaphthalen-2-yl} diazen-1-yl] benzoate. The study assumed the use of Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 with and without S9 metabolic activation system. Trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl] -7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3- sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate was predicted to not induce gene mutation in Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 in the presence and absence of S9 metabolic activation system and hence, according to the prediction made, it is not likely to classify as a gene mutant in vitro.

The ability of trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3-sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate to induce chromosomal aberration was predicted using Chinese hamster ovary (CHO) cells using Danish QSAR database (2017). The end point for chromosome aberrations has been modeled in the Danish QSAR using the three software systems Leadscope, CASE Ultra and SciQSAR. Based on predictions from these three systems, a fourth and overall battery prediction is made. The battery prediction is made using the so called Battery algorithm. With the battery approach it is in many cases possible to reduce “noise” from the individual model estimates and thereby improve accuracy and/or broaden the applicability domain. Trisodium 4-[(E)-2-{1-hydroxy-6-[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3-sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate does notinduce chromosome aberrations in Chinese hamster ovary (CHO) cells and hence is predicted to not classify as a gene mutant in vitro.

Muzall and Cook (Mutation Research, 1979) peformed gene mutation toxicity for structurally and functionally similar read across chemical FD and C Red no. 2 (RA CAS no 915 -67 -3; IUPAC name: trisodium (4E)-3-oxo-4-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-3,4-dihydronaphthalene-2,7-disulfonate). Spot test was performed at dose levels from 10-250 mg using Salmonella typhimurium strain TA98, TA1537, TA100, TA1535 with and without S9 metabolic activation system. Captan was used as positive control chemical and the solvent control used was DMSO. Mutagenicity was indicated by a clustering of revertant colonies directly around the test material or at the edge of the inhibitory zone. FD&C Red No. 2 did not induce clustering of revertant colonies directly around the test material or at the edge of the inhibitory zone using Salmonella typhimurium strain TA98, TA1537, TA100, TA1535 in the presence and absence of S9 metabolic activation system and hence is not likely to classify as a gene mutant in vitro.

In the same study by Muzall and Cook, Gene mutation toxicity study was performed to determine the mutagenic nature of structurally and functionally similar read across chemical FD&C Red No. 2 (RA CAS no 915 -67 -3; IUPAC name: trisodium (4E)-3-oxo-4-[2-(4-sulfonatonaphthalen-1-yl)hydrazin-1-ylidene]-3,4-dihydronaphthalene-2,7-disulfonate). The study was performed as per the plate incorporation assay using Salmonella typhimurium strain TA98, TA1537, TA100, TA1535 with and without S9 metabolic activation system. The 2 ml of liquid top agar was cooled to 45°C and 0.1 ml of a broth cultureof microorganism and test substance in volumes of≤0.4 ml of DMSO was added prior to placing on minimal agar plates. The plates were incubated for 48 h at 37°C and the colonies which reverted to the prototroph were counted and compared to counts on the control plate (containing no test substance) to demonstrate mutagenicity or toxicity. Materials which caused a 2-fold increase of revertants, as compared to the number of spontaneous revertants on the control plates, were denoted as mutagens. Those which reduced the number of revertants were considered inhibitory. FD&C Red No. 2 did not result in a 2-fold increase in the number of revertants as compared to the number of spontaneous revertants on the control plates in Salmonella typhimurium strain TA98, TA1537, TA100, TA1535 in the presence and absence of S9 metabolic activation system and hence is not likely to classify as a gene mutant in vitro.

In another study by Zeiger et al (Environmental Mutagenesis, 1986), Gene mutation toxicity study was performed for structurally and functionally similar read across chemical direct blue 25 (RA CAS no 2150 -54 -1; IUPAC name: Tetrasodium 3,3'-[(3,3'-dimethyl[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[4,5-dihydroxynaphthalene-2,7-disulphonate]) to evaluate its mutagenic nature. The study was performed as per the preincubation protocol using Salmonella typhimurium strain TA100, TA1535, TA1537, TA98 both in the presence and absence of S9 metabolic activation system at doses of 0, 100.0, 333.0, 1000.0, 3333.0 or 10000.0 µg/plate. Water was used as the vehicle. The plates were incubated for 48 hrs after 20 mins preincubation before the evaluation of the revertant colonies could be made. Direct blue 25 did not induce mutation in the Salmonella typhimurium strain TA100, TA1535, TA1537, TA98 both in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Based on the data available for the target chemical and its read across, 4-[(E)-2 -{1-hydroxy-6 -[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3-sulfonatonaphthalen-2-yl}diazen-1-yl]benzoate does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.

Justification for classification or non-classification

Based on the data available for the target chemical and its read across, 4-[(E)-2 -{1-hydroxy-6 -[({5-hydroxy-6-[(E)-2-phenyldiazen-1-yl]-7-sulfonatonaphthalen-2-yl}carbamoyl)amino]-3-sulfonatonaphthalen-2-yl}diazen-1-yl] benzoate does not exhibit gene mutation in vitro. Hence the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.