Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

The test item was assessed for its potential to induce gene mutations in the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100, and the Escherichia coli strain WP2 uvrA, according to the OECD guideline 471.

The assay was performed in two independent experiments both with and without microsomal activation. Each concentration and the controls were tested in triplicate. The test item was tested at the following concentrations:

Pre-Experiment/Experiment I: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate

Experiment II: 33, 100, 333, 1000, 2500 and 5000 µg/plate

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without S9 mix in both experiments.

No toxic effects, evident as a reduction in the number of revertants occurred in the test groups with and without metabolic activation.

No substantial increase in revertant colony numbers of any of the five tester strains was observed at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

It can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frame shifts in the genome of the strains used.

The substance is a member of the Stilbene Fluoorescent Whitening Agent category, group 2. Within the whole category ten over fourteen registered substances covering at least one member per group/subgroup (see data matrix in the Category Justification Report attached to the section 13 of the dossier) was tested for bacteria reverse mutation and chromosomal aberration and none of the existing tests arisen any concern for mutagenicity or genotoxicity .

Furthermore, all substances of the category were modelled with OECD Toolbox and the provisional results about mutagenicity alerts were calculated for all members and their metabolites. The same alert was reported based on the H-acceptor-path3-H-acceptor. This alert explores the possibility that a chemical interacts with DNA and/or proteins via non-covalent binding, such as DNA intercalation or groove-binding (Snyder et al. 2006). Among the descriptors potentially accounting for non-covalent interactions, the present molecular framework representing two bonded atoms connecting two H bond acceptors (calculated with software Leadscope Enteprise 2.4.15-6) resulted in an increased sensitivity/specificity for what concerns the Micronucleus training set. Experimental tests both in vivo and in vitro demonstrate that this alert is not expressed in none of the substances of the group. Based on all those considerations the available studies on the analogous substances are representative for the substance under registration also that can then be considered as not genotoxic

Read across within the same group is well justified in this case also taking into account the impurities of the considered substances, since the identified organic impurities can have different substitution on the molecule, but the functional reactive groups are potentially the same and Read Across is justified.

Short description of key information:
Ames test (according to OECD Guideline 471 (Bacterial Reverse Mutation Assay): negative with and without metabolic activation

Endpoint Conclusion:

Justification for classification or non-classification

The available experimental data are adequate for classification and labelling and the substance is not classified for genetic toxicity according to CLP Regulation (EC 1272/2008).