Reaction mass of 3,3'-(1E,1'E)-(4,4'-(6-(bis(2-hydroxyethyl)amino)-1,3,5-triazine-2,4-diyl)bis(azanediyl)bis(3-methoxy-4,1-phenylene))bis(diazene-2,1-diyl)dibenzenesulfonic acid and disodium 3,3'-[[6-[bis(2-hydroxyethyl)amino]-1,3,5-triazine-2,4-diyl]bis[imino(3-methoxy-4,1-phenylene)azo]]bis[benzenesulphonate]

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Non mutagenic in bacteria reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

As no data on target substance was available, a read across approach was followed, as detailed in section 13. In particular, available data on Similar Substance 02 was used.

A study on the potential of Similar Substance 02 to induce gene mutations in Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 was available. The study was run in 2 independent experiments using the pre-incubation mehod for azo dyes. Similar Substance 02 was tested at concentrations of 10.0, 100.0, 333.3, 1000.0 and 5000.0 µg/plate.

Only weak toxic effects, as reduction in the number of spontaneous revertants, occurred at the highest dose in TA 1537 with metabolic activation (exp. I) and in TA 98 at 10.0 and 5000.0 µg/plate without metabolic activation and at 5000.0 µg/plate with metabolic activation (exp. I). Plates incubated with test substance showed normal back-ground growth up to 5000.0 µg/plate with and without S9 mix in all strains used. Test substance induced a slight increase in the number of revertants in strain TA 1535 at 10.0 and 1000.0 µg/plate without metabolic activation (exp. I), in TA 98 at 10.0 µg/plate (exp. I) and in TA 1537 at 333.3 µg/plate (exp. II) both with metabolic activation.

Up to the highest dose, no significant and reproducible dose-dependent increase in revertant colony numbers was obtained in any of the strains used with or without metabolic activation.

A second test was tun using the same Salmonella typhimurium strains, i.e. TA 1535, TA 1537, TA 98 and TA 100. Selection of a dose-range was based on a preliminary toxicity test with strain TA100, both with and without S9-mix.

In the toxicity test, no effect on TA 100 strain both with and without metabolic activation was seen up to 5000 µg/plate. In the main experiment, 5 doses were tested: 100, 333, 1000, 3330 and 5000 µg/plate.

No dose-related increase in the number of revertant (his+) colonies in any strain was seen. These results were confirmed in an independently repeated experiment.

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), a mutation means a permanent change in the amount or structure of the genetic material in a cell. The term ‘mutation’ applies both to heritable genetic changes that may be manifested at the phenotypic level and to the underlying DNA modifications when known.

The more general terms ‘genotoxic’ and ‘genotoxicity’ apply to agents or processes which alter the structure, information content, or segregation of DNA, including those which cause DNA damage by interfering with normal replication processes, or which in a non- physiological manner (temporarily) alter its replication.

For the purpose of classification for germ cell mutagenicity, substances are allocated to one of two categories:

 

Category 1: substances known to induce heritable mutations or to be regarded as if they induce heritable mutations in the germ cells of humans.

Category 1A: based on positive evidence from human epidemiological studies.

Category 1B: based on:

- positive result(s) from in vivo heritable germ cell mutagenicity tests in mammals; or

- positive result(s) from in vivo somatic cell mutagenicity tests in mammals, in combination with some evidence that the substance has potential to cause mutations to germ cells.

- positive results from tests showing mutagenic effects in the germ cells of humans, without demonstration of transmission to progeny; for example, an increase in the frequency of aneuploidy in sperm cells of exposed people.

 

Category 2: substances which cause concern for humans owing to the possibility that they may induce heritable mutations in the germ cells of humans, based on positive evidence obtained from experiments in mammals and/or in some cases from in vitro experiments, obtained from:

- somatic cell mutagenicity tests in vivo, in mammals; or

- other in vivo somatic cell genotoxicity tests which are supported by positive results from in vitro mutagenicity assays

 

Based on negative results in available experimental studies, a mutagenic potential for target substance was excluded.

Accordingly, the substance was not classified under the CLP Regulation (EC 1272/2008).