Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated

Endpoint summary

Additional information

Gene mutation in bacteria

The substance Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated was tested for potential induction of gene mutations in bacteria in a study conducted according to OECD guideline 471 and GLP (Bowles, 2004). Salmonella typhimurium strains TA1535, TA1537, TA89 and TA100 and Escherichia coli strain WP2 uvrA- were treated with the test material using the plate incorporation method at five concentrations from 50 to 5000 µg/plate both with and without metabolic activation (S9 mix). Appropriate vehicle (acetone) and positive controls were included. An independent repeat experiment was conducted under the same test conditions.

No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains at any concentration, either with or without metabolic activation. The test material caused no visible reduction in the growth of the bacterial background lawn at any concentration. A clear, oily precipitate was observed at and above 1500 µg/plate. The number of revertant colonies in the vehicle control plates was within the normal range. All positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with or without metabolic activation.

The test material is thus considered to be non-mutagenic under the conditions of this test.

Chromosome aberrations

A study was conducted with Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated to detect the potential induction of structural chromosomal aberrations in cultured mammalian cells according to OECD guideline 473 and in compliance with GLP (Wright, 2004). Duplicate cultures of human lymphocytes, treated with the test material, were evaluated for chromosome aberrations at four concentrations up to 2500 µg/mL, along with vehicle (DMSO) and positive controls, both in the presence and absence of metabolic activation (S9 mix). Two independent experiments were performed. In the first experiment, cells were treated with the test material for 4 h (with and without S9 mix) and harvested after a 20-hour expression period. In the second experiment, the 4 h exposure with metabolic activation and 20-hour expression period was repeated, while in the absence of metabolic activation exposure was increased to 24 h.

The test material was slightly toxic at 2500 µg/mL (precipitating concentration) and did not induce any statistically significant increases in the frequency of cells with aberrations. All vehicle controls had frequencies of cells with aberrations within the range expected for normal human lymphocytes. All positive control materials induced statistically significant increases in the frequency of cells with aberrations.

The test material is thus considered to be non-clastogenic to human lymphocytes in vitro.

Gene mutation in mammalian cells

The potential mutagenicity of Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated on the thymidine kinase, TK +/-, locus of the L5178Y mouse lymphoma cell line was assessed in a GLP-compliant study conducted according to OECD guideline 476 (Flanders, 2012). L5178Y TK +/- 3.7.2c mouse lymphoma cells were treated with the test material at eight concentrations ranging from 9.77 to 1250 µg/mL with and without metabolic activation system (S9 mix). Vehicle (DMSO) and positive controls were included. Two independent experiments were performed. In the first experiment, cells were exposed to the test material for 4 h in the presence and absence of S9 mix. In the second experiment, cells were treated for 4 h with metabolic activation and for 24 h without metabolic activation.

The test material did not induce any toxicologically significant dose-related increases in the mutant frequency at any dose level, either with or without metabolic activation. With no evidence of any marked toxicity in the preliminary toxicity test, the maximum dose level used in the mutagenicity test was limited by the onset of a greasy/oily precipitate effectively reducing exposure of the test item to the cells. Overall, precipitate of test item was observed at and above 78.13 µg/mL. The vehicle controls had mutant frequency values that were considered acceptable for the L5178Y cell line at the TK +/- locus. The positive control items induced marked increases in the mutant frequency.

The test material is thus considered to be non-mutagenic to L5178Y cells under the conditions of the test.

Conclusions for genetic toxicity (in vitro)

The substance Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated has been tested for mutagenicity in bacteria and for cytogenicity and mutagenicity in mammalian cells. All available in vitro studies were negative.

Based on the available data, the substance is considered to be not mutagenic and not clastogenic in vitro.

Justification for selection of genetic toxicity endpoint
No study was selected, since all available in vitro genetic toxicity studies were negative.

Short description of key information:
Gene mutation in bacteria (Ames test): negative in S. typhimurium TA 1535, TA 1537, TA 98 and TA 100 and E. coli WP2 uvr A with and without metabolic activation (OECD 471/EU Method B.13/14, GLP)
Cytogenicity: negative in cultured peripheral human lymphocytes with and without metabolic activation (OECD 473/EU Method B.10, GLP)
Gene mutation in mammalian cells: negative in Mouse lymphoma L5178Y cells without metabolic activation (OECD 476/EU Method B.17, GLP)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available data on the in vitro genetic toxicity of Fatty acids, C18-unsatd., dimers, di-Me esters, hydrogenated do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.