N-[3-(dimethylamino)propyl]oleamide

Endpoint summary

Additional information

Trennmittel ZM 121 was tested in three different in vitro genetic toxicity assays: in a bacterial reverse mutation (Ames) assay according to OECD guideline 471, in a chromosome aberration assay according to OECD guideline 473, and in a mammalian gene mutation test according to OECD guideline 476.

In the mammalian gene mutation assay (BASF, 2008), the test substance was tested for its ability to induce gene mutations at the HPRT locus in CHO cells in vitro. Two independent experiments were carried out with and without metabolic activation, using test substance concentrations of 0-20 μg/ml (with and without S9 mix) in experiment 1, as well as 0-6 μg/ml (without S9 mix) and 0-20 μg/ml (with S9 mix) in experiment 2. A pretest for toxicity showed strong cytotoxicity at 20 μg/ml and above.

After a 20-24 hour attachment period, the cells were treated with the test substance for 4 hours, followed by an expression phase of 6 -8 days and a selection period in medium containing 10 μg/ml 6-thioguanine of about 1 week. The colonies of each test group were fixed with methanol, stained with Giemsa and counted.

The vehicle controls gave mutant frequencies within the range expected for the CHO cell line. The positive control substances led to the expected increase in the frequencies of forward mutations. It can be concluded that under the experimental conditions chosen, the test item is not mutagenic in the HPRT locus assay using CHO cells in the absence and the presence of metabolic activation.

In the chromosome aberration test (RCC-CCR, 2008), the test item was tested for its potential to induce structural chromosome aberrations in V79 cells in vitro in three independent experiments: In Experiment I, the exposure period was 4 hours with and without metabolic activation. In Experiment IIA the exposure period was 4 hours with S9 mix and 18 hours and 28 hours without S9 mix. In Experiment IIB the exposure period was 4 hours with S9 mix. The chromosomes were prepared 18 hours (Exp. I and IIA) and 28 hours (Exp. IIA and IIB) after start of treatment with the test item.

In Experiment I in the absence and presence of S9 mix and in Experiment IIA in the presence of S9 mix, concentrations showing clear cytotoxicity were not scorable for cytogenetic damage. In Experiment IIA in the absence of S9 mix and in Experiment IIB in the presence of S9 mix clear cytotoxicity was observed at the highest evaluated concentrations.

In Experiment I, in the absence and the presence of S9 mix and in Experiment IIA, in the absence of S9 mix no clastogenicity was observed up to the highest evaluable concentrations. A slight but statistically significant increase in the number of aberrant cells excluding gaps (5.5%) was observed at the highest evaluated concentration (20 μg/mL). This finding could, however, not be verified in the confirmatory Experiment IIB.

No relevant increase in the frequencies of polyploid metaphases was found after treatment with the test as compared to the frequencies of the controls. Appropriate mutagens were used as positive controls. They induced statistically significant increases (p<0.05) in cells with structural chromosome aberrations. The test substance is considered to be non-clastogenic in this chromosome aberration test with and without S9 mix, when tested up to the highest evaluable concentrations.

In the Ames assay (LAUS, 2008), the mutagenic potential of Trennmittel ZM 121 in Salmonella typhimurium strains TA 97a, Ta 98, TA 100, TA 102 and TA 1535 was evaluated. Five experiments were conducted.

ln the first experiment, the test item showed cytotoxicity towards the bacteria in the highest concentration (5052µg/plate).

ln consideration of this result, the second experiment was performed using 1500µg/plateas maximum concentration. Signs of toxicity towards the bacteria were observed in all three concentrations in the secend experiment. The third experiment was performed as toxicity test with four concentrations in order to determine the Iimit of toxicity. Regarding the result of the third experiment, in the fourth experiment, 50 µg/plate was chosen as highest concentration. The culture of tester strain TA97a did not show growth. Therefore, a fifth experiment was performed in the same fashion using the strain TA 97a. ln both fourth and fifth experiment, no mutagenic effects of the test item could be determined. The confirmation tests of the genetype did not show any irregularities. ln all experiments, the control of the titre was above the demanded value. Tthe number of revertant colonies in the positive controls was in the range of the historical data of the laboratory and were definitely increased in comparison with the negative controls, as well as showing mutagenic potential of the diagnostic mutagenes. It can be concluded that under the test conditions chosen, the test item is not mutagenic in the Bacterial Reverse Mutation Test using when using concentrations just below the limit of toxicity.

Short description of key information:
The test substance was tested for mutagenicity and chromosome aberration in vitro in mammalian cells (according to OECD guidlines 476 and 473, respectively) and bacteria (according to OECD guideline 471). It did not induce chromosome aberration and was not mutagenic in these test systems. Thus, no classification according to Regulation (EC) No 1272/2008 (CLP) is required.

Endpoint Conclusion:

Justification for classification or non-classification

Taking into account the whole of information available from three different in vitro systems to assess genetic toxicity, it can be concluded that the test item Trennmittel ZM 121 is not genotoxic in vitro. A classification according to Regulation (EC) No 1272/2008 (CLP) is therefore not warranted.