1H-Benzimidazole-5,7-disulfonic acid, 2,2'-(1,4-phenylene)bis-, sodium salt (1:2)

Endpoint summary

Additional information

Ames test:

The bacterial reverse mutation assay / Ames test (King_1996) performed according to OECD 471 (outdated version, adopted May 26, 1983) was rated with RL=2 (reliable with restrictions) because it does not totally comply with the requirements of the current version of the testing guideline. It is used as a key study. There are no significant deviations to the guideline version of 1983, however acc. to the current guideline version the 5th strain TA102 or E.coli WP2 should be used for detection of cross-linking mutagens. In the described study TA1538 was used instead. However, according to ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7a (may 2008), R.7.7.6.3 "Testing strategy for mutagenicity","For substances with significant toxicity to bacteria, not taken up by bacteria, or for which the gene mutation test in bacteria cannot be performed adequately, an in vitro mammalian cell gene mutation test may be used as an alternative test." Thus, in combination with the results of the available mammalian chromosome aberration test, the result of the bacterial reverse mutation test is considered as reliable.The results indicate that Neo Heliopan® AP under the experimental conditions described (concentration range in the main test: experiment I and II: 0, 50, 150, 500, 1500, 5000 µg/plate) is not mutagenic to Salmonella typhimurium strains TA1535, TA1537, TA98, TA100, and TA 1538 in the presence and absence of a metabolizing system.

Chromosome aberration test:

The in-vitro mammalian chromosome aberration test (King_1996) performed according to OECD 473 was rated with RL=2 (reliable with restrictions) and used as a key study. The test item Neo Heliopan® AP did not induce structural chromosomal aberrations in human lymphocytes. Therefore, Neo Heliopan® AP is considered to be non-clastogenic in the chromosome aberration test when tested up to the highest concentration of 5000 µg/mL with and without metabolic activation (S9 mix).

HPRT test:

The mammalian cell gene mutation assay (Herbold_1998) performed according to OECD 476 was rated with RL=1 (reliable without restrictions) and used as a key study. The results indicate that Neo Heliopan® AP under the experimental conditions described did not induce mutation at the hprt locus in Chinese hamster lung fibroblasts (V79). These conditions included treatments up to a maximum concentration of 5000 µg/mL in two independent experiments in the absence and presence of a rat liver metabolic activation system (S9 mix).

Short description of key information:
In-vitro studies:
Bacterial reverse mutation assay / Ames test (OECD 471): negative
Mammalian chromosome aberration test (OECD 473): negative
Mammalian cell gene mutation assay / hprt test (OECD 476): negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

All available reliable studies showed no genetic toxicity for the substance. Thus, no classification is required for the time being according to Regulation (EC) 1272/2008 and subsequent regulations.