5-(C11-C12 alkyl, branched)-2-hydroxy-benzaldehyde oxime

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames-Test (BASF, 2013):negative
HPRT-Test (Harlan CCR, 2013): negative
in vitro Chr. Abbr. (BASF, 2014): negative

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Ames-Test

The test substance 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. The test was conducted according to OECD 471 guideline and GLP (BASF, 2013).

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

DOSE RANGE: 33 μg - 5 000 μg/plate (SPT); 33 μg - 5 000 μg/plate (PIT)

TEST CONDITIONS: Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (liver S9 mix from induced rats).

SOLUBILITY: Precipitation of the test substance was found from about 2 500 μg/plate onward with and without S9 mix.

TOXICITY: A weak bacteriotoxic effect was occasionally observed depending on the strain and test conditions from about

1 000 μg/plate onward.

MUTAGENICITY:

A biologically relevant increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system.

CONCLUSION:

Thus, under the experimental conditions of this study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the

absence and the presence of metabolic activation.

HPRT-Test:

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

The assay was performed in two independent experiments, using two parallel cultures each. The main experiments were performed with and without liver microsomal activation and a treatment period of 4 hours.

The highest concentration of 3060 μg/mL in the pre-experiment was equal to approximately 10 mM. The concentration range of the main experiments was limited by cytotoxic effects. The test item was dissolved in acetone.

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 (EMS 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.

Conclusion

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, the test substance is considered to be non-mutagenic in this HPRT assay.

In vitro Chr. Abr. Test

The substance was assessed for its potential to induce structural chromosome aberrations (clastogenic activity) and/or changes in the number of chromosomes (aneugenic

activity) in V79 cells in vitro in a study according to OECD 473 guideline and GLP (BASF, 2014). Four independent experiments were carried out, both with and/or without the addition of liver S9 mix from induced rats (exogenous metabolic activation).

According to an initial range-finding cytotoxicity test for the determination of the experimental doses, the following doses were tested. The test groups printed in bold type were evaluated.

1st Experiment

4-hour exposure, 18-hour sampling time, without S9 mix

0; 0.78; 1.56; 3.13; 6.25; 12.5; 25; 50; 100 μg/mL

4-hour exposure, 18-hour sampling time, with S9 mix

0; 0.78; 1.56; 3.13; 6.25; 12.5; 25; 50; 100 μg/mL

2nd Experiment (confirmatory experiment)

4-hour exposure, 18-hour sampling time, without S9 mix

0; 0.39; 0.78; 1.56; 3.13; 6.25; 12.5 μg/mL

4-hour exposure, 18-hour sampling time, with S9 mix

0; 1.56; 3.13; 6.25; 12.5; 25; 50 μg/mL

3rd Experiment

18-hour exposure, 18-hour sampling time, without S9 mix

0; 0.39; 0.78; 1.56; 3.13; 6.25; 12.5; 25 μg/mL

18-hour exposure, 28-hour sampling time, without S9 mix

0; 0.78; 1.56; 3.13; 6.25; 12.5; 25 μg/mL

4-hour exposure, 28-hour sampling time, with S9 mix (unscorable due to poor slide quality)

0; 1.56; 3.13; 6.25; 12.5; 25; 50 μg/mL

4th Experiment

4-hour exposure, 28-hour sampling time, with S9 mix

0; 1.56; 3.13; 6.25; 12.5; 25; 50 μg/mL

A sample of 100 metaphases for each culture was analyzed for chromosomal aberrations, except for the positive control cultures where only 50 metaphases were scored due to clearly increased aberration rates.

The vehicle controls gave frequencies of aberrations within the range expected for the V79 cell line. Both positive control substances, EMS and cyclophosphamide, led to the expected increase in the number of cells containing structural chromosome aberrations.

Cytotoxicity indicated by clearly reduced cell numbers or mitotic rates was observed at least at the highest applied test substance concentration in all experimental parts of this study.

In the 1st Experiment in the absence and presence of metabolic activation aberration rates slightly exceeding either the concurrent vehicle control values or our laboratory’s historical negative control data range were obtained. But, the values showed neither statistical significance compared with the concurrent vehicle control values nor dose-dependancy. In the 2nd Experiment these observations were not confirmed. Thus, the findings in the 1st Experiment have to be regarded as biologically irrelevant.

Finally, on the basis of the results of the present study, the test substance did not cause a biologically relevant increase in the number of structurally aberrant metaphases incl. and excl. gaps at both sampling times either without S9 mix or after adding a metabolizing

system.

Although there were two single findings concerning the induction of endoreduplicated metaphase cells after treatment in the presence of metabolic activation, no biologically relevant increase in the frequency of cells containing numerical chromosome aberrations was

demonstrated.

Thus, under the experimental conditions described, the substance is considered not to have a chromosome-damaging (clastogenic) effect under in vitro conditions in V79 cells in the absence and the presence of metabolic activation.

There is no indication from the above mentioned tests that the registered substance could have any mutagenic effect or could induce chromosome aberrations.

Justification for classification or non-classification

Based on the available data, the substances does not have to be labelled with regard to genetic toxicity.