N-[3-(dimethylamino)propyl]stearamide

Endpoint summary

Additional information

Stearic acid 3-(dimethylaminopropyl)amide is not mutagenic in the Salmonella typhimurium reverse mutation assay and the mammalian cell gene mutation assay (TK test) using mouse lymphoma L5178Y cells. In an in vitro mammalian cell cytogenetics assay Stearic acid 3-(dimethylaminopropyl)amide did not induce structural chromosomal aberrations in cultured peripheral human lymphocytes. Based on the available data, there was no evidence of genotoxicity for Stearic acid 3-(dimethylaminopropyl)amide. In conclusion, there is no need to carry out in vivo tests for genetic toxicity. There are no data gaps for this endpoint.

No human data are available for genetic toxicity. However, there is no reason to believe that the negative results would not be relevant to humans.

 

Bacterial reverse gene mutation assay

In a reverse gene mutation assay in bacteria equivalent to OECD guideline 471, strains ofS. typhimurium(TA 1535, TA 1537, TA 98 and TA 100) andE. coli(WP2 uvr A) were exposed to Stearic acid 3-(dimethylaminopropyl)amide (a.i. 85 %) forS. typhimuriumat concentrations of 5, 10, 25, 50, and 75 µg/plate in the absence of mammalian metabolic activation, and at concentrations of 25, 50, 75, 100 and 250 µg/plate in the presence of mammalian metabolic activation. Strain E. coli WP2uvrA was tested at concentrations of 10, 25, 50, 75, and 100 µg/plate in the absence and at 50, 75, 100, 250, and 500µg/plate in the presence of metabolic mammalian activation.

Two tests were performed, the first test using the plate incorporation and the second test the preincubation method.

 In the first mutation assay (plate incorporation) Stearic acid 3-(dimethylaminopropyl)amide did not induce a significant dose-related increase in the number of revertant colonies in all five tested strains, both in the absence and presence of mammalian metabolic activation. These results were confirmed in the second mutation assay (preincubation method). No precipitation was observed.

Cytotoxic effects of the test substance were observed in the preincubation assay in allS. typhimuriumstrains, at a concentration of >/= 50 µg/plate in the absence of mammalian metabolic activation. Additionally at range finding test cytotoxic effects were shown at >/= 500 µg/plate in the E. coli. WP2 uvr A strain.

The positive controls induced the appropriate responses in the corresponding strains and metabolic activation was confirmed.

 There was no evidence of induced mutant colonies over background.

 

Mammalian cell gene mutation assay

In a mammalian cell gene mutation assay according to OECD guideline 467, adopted July 21, 1997 (thymidine kinase (TK)),L5178Y mouse lymphoma cells cultured in vitro were exposed to Stearic acid 3-(dimethylaminopropyl)aminde (100% purity) in ethanol in the following concentrations in the presence and absence of mammalian metabolic activation (S9 mix):

First experiment

Without S9-mix, 3 h treatment: 0.003, 0.01, 0.03, 0.1, 0.3, 1, 2.5 and 5 μg/mL

With 8% S9-mix, 3 h treatment: 0.1, 0.6, 1, 5, 10, 20, 30 and 40 μg/mL

Second experiment

Without S9-mix, 3 h treatment: 0.01, 0.03, 0.1, 0.3, 0.6, 1 and 3 μg/mL

With 12% S9-mix, 24 h treatment: 0.1, 1, 3, 10, 30, 40, 50 and 60 μg/mL

Stearic acid 3-(dimethylaminopropyl)aminde was tested up to cyctotoxic concentrations.The positive controls induced the appropriate response.

There was no evidence of induced mutant colonies over background.

 

Mammalian cell cytogenetics assay

In a mammalian cell cytogenetics assay (chromosome aberrations) according to OECD guideline 473, adopted 21 July 1997 and EU Method B.10, May 2008, peripheral human lymphocyte cultures were exposed to Stearic acid 3-(dimethylaminopropyl)amide in Ethanol at the following concentrations:

 First experiment: without and with S9-mix (3 h exposure time, 24 h fixation time): 0, 1, 3 and 10 μg/mL

 Second experiment: without S9-mix (24 h and 48 h exposure time, 24 h and 48 h fixation time): 0, 3, 6, 10, 15, 20 and 25 μg/mL; with S9-mix (3 h exposure time, 48 h fixation time): 0, 1, 3 and 10 μg/mL

The number of cells with chromosome aberrations found in the solvent control cultures was within the laboratory historical control data range. The number of polyploid cells and cells with endoreduplicated chromosomes in the solvent control cultures was within the laboratory historical control data range. The positive control chemicals (MMC-C and CP) both produced statistically significant increases in the frequency of aberrant cells. It was therefore concluded that the test conditions were adequate and that the metabolic activation system (S9-mix) functioned properly.

Stearic acid 3-(dimethylaminopropyl)amide was tested up to precipitating concentrations (10 µg/mL).

Both in the absence and presence of S9-mix Stearic acid 3-(dimethylaminopropyl)amide did not induce a statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in two independent experiments.

No effects of Stearic acid 3-(dimethylaminopropyl)amide on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Therefore it can be concluded that Stearic acid 3-(dimethylaminopropyl)amide does not disturb mitotic processes and cell cycle progression and does not induce numerical chromosome aberrations under the experimental conditions described in this report.

There was no evidence of chromosome aberrations induced over background.

Justification for selection of genetic toxicity endpoint
No single key study has been selected since all available studies were negative.

Short description of key information:
Negative in all tests conducted:

- Ames test with S. typhimurium TA 98, TA 100, TA 1535, TA 1537, E coli WP2 uvrA (met. act.: with and without) (OECD TG 471 and GLP); cytotoxicity was observed at a concentration of >/= 50 µg/plate for the S. typhimurium strains and at >/= 500 µg/plate for E. coli.

- Mammalian cell gene mutation assay with mouse lymphoma L5178Y cells (TK) (met. act.: with andwithout) (OECD Guideline 476 and GLP); cytotoxicity was observed at concentrations of > 4 µg/mL without S9 mix and > 50 µg/mL with S9.

- In vitro mammalian chromosome aberration test with cultured peripheral human lymphocytes (met. act.: with andwithout) (OECD Guideline 473 and GLP); cytotoxicity: no (but tested up to precipitating concentrations)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Stearic acid 3-(dimethylaminopropyl)amide is not mutagenic in the Salmonella typhimurium reverse mutation assay and the mammalian cell gene mutation assay using mouse lymphoma L5178Y cells. In an in vitro chromosomal aberration test, the test item did not induce structural chromosomal aberrations. Therefore, Stearic acid 3-(dimethylaminopropyl)amide is considered to be non-clastogenic.

In conclusion the full set of genotoxicity tests required by the REACH regulation is negative. According to Directive 67/548/EEC as well as GHS Regulation EC No 1272/2008 no classification and labelling for mutagenic toxicity is necessary.