Reaction mass of disodium 3-[(5-chloro-2-phenoxyphenyl)azo]-4-hydroxy-5-[[(p-tolyl)sulphonyl]amino]naphthalene-2,7-disulphonate and 3-[(5-chloro-2-phenoxyphenyl)azo]-4-hydroxy-5-[[(ptolyl)sulphonyl]amino]naphthalene-2,7-disulphonic acid

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

no gene mutations in the strains of Salmonella typhimurium tested

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

The evaluation of the genetic toxicity has been based on the Read Across approach:

Acid Red 249:1 is a multiconstituent substance composed by the acidic and the sodium salt forms of the same structure (72.7 % and 14.95 % of the substances respectively).

The tests was performed on the Similar Substance 01 which is the major component of the multiconstituent substance. Considering the high similarity between the structures and the composition of the substance the Read Across approach is considered as acceptable. See section 13.

Similar Substance 01 has been tested for mutagenic effects in vitro in histidine-requiring strains of Salmonella typhimurium. The following strains of Salmonella typhimunum were used: TA 98, TA 100, TA 1535 and TA 1537. No E. Coli stain was used.

The test was performed with and without the addition of rat-liver post mitochondrial supernatant (S9 fraction) as an extrinsic metabolic activation system. The compound was dissolved in DMSO and tested at five concentrations in the range of 61.7 to 5000.0 ug/plate in the presence and absence of a metabolic activation system. In order to confirm the results, the experiments were repeated with and without metabolic activation at five concentrations in the range of 61.7 to 5000.0 ug/plate. Each strain was additionally tested in the presence and in the absence of a metabolic activation system with a suitable, known mutagen as positive control.

In both experiments, performed with and without metabolic activation, none of the tested concentrations led to an increase in the incidence of histidine-prototrophic mutants by comparison with the negative control.

Based on the results of these experiments and on standard evaluation criteria, it is concluded that the substance and its metabolites did not induce gene mutations in the strains of Salmonella typhimurium used.

Based on the test conducted on Similar Substance 01, even the Acid Red 249:1 is expected to not induce gene mutations in the strains of Salmonella typhimurium used.

Justification for selection of genetic toxicity endpoint

The test was performed on the major component of the multiconstituent substance

Justification for classification or non-classification

GERM CELL MUTAGENICITY

This hazard class is primarily concerned with substances that may cause mutations in the germ cells of humans that can be transmitted to the progeny. However, the results from mutagenicity or genotoxicity tests in vitro and in mammalian somatic and germ cells in vivo are also considered in classifying substances and mixtures within this hazard class.

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

Categoty 2: Substances which cause concern for humans owing to the possibility that they may induce heritable mutations in the germ cells of humans.

Classification for heritable effects in human germ cells is made on the basis of well conducted, sufficiently validated tests as In vitro mutagenicity tests such as these indicated in 3.5.2.3.8:

- in vitro mammalian chromosome aberration test;

- in vitro mammalian cell gene mutation test;

- bacterial reverse mutation tests

The substance to be registered shows negative results on the strains of Salmonella typhimurium under the performed test, therefore data available are conclusive but not sufficient for the classification, according to the 3.5. of the CLP Regulation n.1272/2008.