Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

In vitro:

Ames-Test:

The testsubstance was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i .e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay according to OECD 471 guideline and GLP (BASF, 2000).

STRAINS : TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA

DOSE RANGE: 20 ug - 5000 ug/plate (SPT; all tester strains); 4 ug - 5000 ug/plate (PIT ; Salmonella strains); 4 ug - 1000 ug/plate (PIT ; E. coli WP2 uvrA )

TEST CONDITIONS: Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (Aroclor-induced rat liver S-9 mix).

SOLUBILITY: No precipitation of the test substance was found.

TOXICITY: A bacteriotoxic effect was observed only in the PIT depending on the strain and test conditions from about 500 - 2500 ug/

plate onward.

MUTAGENICITY:

An increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S-9 mix or after the addition of a metabolizing system.

CONCLUSION:

According to the results of the present study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay under the experimental conditions chosen here.

HPRT-Test:

The study was performed to investigate the potential of Korantin MAT to induce gene mutations at the HPRT locus in V79 cells of the Chinese hamster according to OECD 476 guideline and GLP (Harlan CCR, 2013).

The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 hours.The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation.

The highest concentration (5000 µg/mL) used in the range finding pre-experiment was chosen with respect to the current OECD guideline 476.

The concentration range of the main experiments was limited by cytotoxic effects of the test item. The test item was dissolved in deionised water.

No substantial and reproducible dose dependent increase of the mutation frequency was observed up to the maximum concentration with and without metabolic activation.

Appropriate reference mutagens (and DMBA), used as positive controls, induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test system and the activity of the metabolic activation system.

In conclusion it can be stated that under the experimental conditions reported the test item did not induce gene mutations at the HPRT locus in V79 cells. Therefore, Korantin MAT is considered to be non-mutagenic in this HPRT assay.

in vitro Chromosome Aberration Test:

The test item Korantin MAT, dissolved in deionised water, was assessed for its potential to induce structural chromosome aberrations inV79cells of the Chinese hamsterin vitro in four independent experiments according to OECD 473 guideline and GLP (Harland CCR, 2013).

In each experimental group two parallel cultures were set up. 100 metaphases per culture were evaluated for structural chromosome aberrations, except for the positive control in Experiment IIA after 18 hours continuous treatment without metabolic activation, where only 50 metaphases were evaluated.

The highest applied concentration (5000 µg/mL) was chosen with respect to the current OECD Guideline 473.

Dose selection for the cytogenetic experiments was performed considering the toxicity data and the occurrence of test item precipitation.

In Experiment IA and IB in the absence and presence of S9 mix and Experiment IIA in the presence of S9 mix concentrations showing clear cytotoxicity were not evaluable for cytogenetic damage. However, in Experiment IB in the presence of S9 mix the cell numbers were markedly reduced to 54.6 % of control.In Experiment IIA in the absence of S9 mix and IIB in the presence of S9 mix cytotoxicity was observed at the highest evaluated concentration indicated as reduced mitotic index and/or reduced cell number.

No clastogenicity was observed at the concentrations evaluated either with or without metabolic activation. However, statistically significant increases were observed in Experiment IB after treatment with 400.0 and 500.0 µg/mL in the absence of S9 mix (2.5 and 3.5 % aberrant cells, excluding gaps), in Experiment IIA after treatment with 1250.0 µg/mL in the presence of S9 mix and in Experiment IIB after treatment with 1250.0 and 1750.0 µg/mL in the presence of S9 mix (3.5, 2.5 and 2.0 % aberrant cells, excluding gaps, respectively). The values are clearly within the range of the historical control data (0.0 - 4.0 % aberrant cells, excluding gaps) and therefore regarded as biologically irrelevant.

No relevant increase in polyploid or endomitotic metaphases was found after treatment with the test item as compared to the frequencies of the control cultures.

Appropriate mutagens (and CPA) were used as positive controls. They induced statistically significant increases in cells with structural chromosome aberrations.

In conclusion, it can be stated that under the experimental conditions reported, the test item did not induce structural chromosome aberrations in V79cells (Chinese hamster cell line) in vitro.

Therefore, Korantin MAT is considered to be non-clastogenic in this chromosome aberration test in the absence and presence of metabolic activation, when tested up to cytotoxic or the highest evaluable concentration.


Short description of key information:
Ames-Test (BASF, 2000): negative
HPRT-test (Harlan CCR, 2013): negative
In Vitro Chromosome Aberration Test (Harlan CCR, 2013): negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Negative results were obtained with all three mutagenicity tests. Threfore no classification for mutagenicity is required according to EU directive 67/548/EEC and EU classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.