7-benzamido-4-hydroxynaphthalene-2-sulphonic acid

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 7-(benzoylamino)-4-hydroxynaphthalene-2-sulfonic acid. The study assumed the use of Salmonella typhimurium strainsTA 1535, TA 1537, TA 98, TA 100 and TA 102 with S9 metabolic activation system. 7-(benzoylamino)-4-hydroxynaphthalene- 2-sulfonic acid 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 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 was reviewed to determine the mutagenic nature of

7-benzamido-4-hydroxy-naphthalene-2-sulphonic acid. The summary 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 7-(benzoylamino)-4-hydroxynaphthalene-2-sulfonic acid. 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. 7-(benzoylamino)-4-hydroxynaphthalene- 2-sulfonic acid 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.

Gene mutation toxicity was predicted for 7-benzamido-4-hydroxy-naphthalene-2-sulphonic acid using the battery approach from Danish QSAR database (2017). The study assumed the use of Salmonella typhimurium bacteria in the Ames test. The end point for gene mutation 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. Gene mutation toxicity study as predicted by Danish QSAR for 7-benzamido-4-hydroxy-naphthalene-2-sulphonic acid is negative and hence the chemical is predicted to not classify as a gene mutant in vitro.

The ability of 7-(benzoylamino)-4-hydroxynaphthalene-2-sulfonic acid to induce chromosomal aberration was predicted using Chinese hamster ovary (CHO) cells using the battery approach from Danish QSAR database. 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. The chemical 7-(benzoylamino)-4-hydroxynaphthalene-2-sulfonic acid does not induce chromosome aberrations in Chinese hamster ovary (CHO) cells and hence is predicted to not classify as a gene mutant in vitro.

In a study by Zeiger et al (Environmental Mutagenesis, 1987) for structurally and functionally similar read across chemical, Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters was performed to evaluate the mutagenic nature of the test compound 1(2H)Phthalazinone (RA CAS no 119 -39 -1) using S. typhimurium tester strains TA1535, TA97, TA98 and TA100. The study was performed as per the preincubation assay and the preincubation time was 20 mins and the plates were incubated for 48 hrs. The test compound was dissolved in DMSO and was used at a dosage level of 0, 100, 333, 1000, 3333 or 10000 µg/plate in the preincubation assay of 48 hrs. Concurrent solvent and positive control chemicals were included in the study. 1(2H)Phthalazinone did not induce a reproducible, dose-related increase in his⁺revertants over the corresponding solventin the S. typhimurium tester strains TA1535, TA1537, TA98 and TA100 in the presence and absence of S9 metabolic activation system and hence is negative for mutation in vitro.

Another structurally and functionally similar read across chemical N-methylbenzamide (RA CAS no 613 -93 -4) was studied for its ability to induce mutations in strains of Salmonella typhimurium by Zeiger et al (Environmental and molecular mutagenesis, 1988). The test compound was dissolved in DMSO and was tested at concentration of 0, 100, 333, 1000, 3333 or 10000 µg/plate using Salmonella typhimurium TA100, TA1535, TA97 and TA98 in the presence and absence of 10 % and 30 % rat and hamster liver S9 metabolic activation system. Preincubation assay was performed with a preicubation for 20 mins. The plates were observed for histidine independence after 2 days incubation period. Concurrent solvent and positive controls were included in the study. N-methylbenzamide is not mutagenic to the Salmonella typhimurium TA100, TA1535, TA97 and TA98 in the presence and absence of rat and hamster liver S9 metabolic activation system.

Based on the data available for the target chemical and its read across, 7-benzamido-4-hydroxy-naphthalene-2-sulphonic acid does not exhibit gene mutation in vitro. Hence it is not likely to classify as a gene mutant in vitro.

Justification for classification or non-classification

Based on the data available for the target chemical and its read across, 7-benzamido-4-hydroxy-naphthalene-2-sulphonic acid (CAS no 132 -87 -6) does not exhibit gene mutation in vitro. Hence it is not likely to classify as a gene mutant in vitro.