Fatty acids, C18 unsaturated, ethyl & methyl esters

Endpoint summary

Additional information

Genetic toxicity

Justification for read-across

There are no data regarding genetic toxicity available for Fatty acids, C18 unsaturated, ethyl & methyl esters. In order to fulfil the standard data requirements defined in Regulation (EC) No 1907/2006, Annex VIII, 8.4, read-across to appropriate substances is conducted in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5.

According to Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met”. In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across) “to avoid the need to test every substance for every endpoint”.

Fatty acids, C18 unsaturated, ethyl & methyl esters is a multi-constituent substance specified by esters of ethanol and methanol with fatty acids C18 unsaturated (source canola oil) resulting in monoesters which meets the definition of an UVCB substance. Thus, the test substance represents fatty acid esters which undergo to a high extent hydrolysis by ubiquitous expressed gastrointestinal enzymes into the free fatty acid components and the respective alcohol moieties (Lehninger, 1970; Mattson and Volpenhein, 1972). Considering the common metabolism, the read-across approach is based on the presence of a common functional group, common precursors and the likelihood of common breakdown products via biological processes, which result in structurally similar chemicals with similar physico-chemical, toxicological and toxicokinetic behaviour. For further details on the read-across approach, please refer to the analogue justification in section 13 of the technical dossier.

As no data on genetic toxicity are available for Fatty acids, C18 unsaturated, ethyl & methyl esters, read-across to reliable data on the analogue substance Methyl laurate (CAS 111-82-0) was conducted for genetic toxicity. Methyl laurate (CAS 111-82-0) is also a fatty acid ester which is composed of methanol (alcohol moiety) and lauric acid (C12 fatty acid moiety) and is therefore regarded as structurally similar to Fatty acids, C18 unsaturated, ethyl & methyl esters and hence, is considered as suitable analogue substance.

Genetic toxicity in bacteria (Ames)

CAS 111-82-0

An Ames test was performed according to OECD Guideline 471 with Methyl laurate (CAS 111-82-0) dissolved in acetone in Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100 and with E. coli WP2uvr A (National Institute of Health Sciences, 2000). Test substance concentrations of 1.56, 3.13, 6.25, 12.5, 25 and 50 µg/plate (TA 100 and TA 1537); 6.25, 12.5, 25, 50, 100 and 200 µg/plate (TA 1535 and TA 98); 313, 625, 1250, 2500 and 5000 µg/plate (E. coli WP2uvr A) without metabolic activation and 12.5, 25, 50, 100, 200 and 400 µg/plate (TA 1537); 25, 50,100, 200, 400 and 800 (TA 100 and TA 1535); 50, 100, 200, 400, 800 and 1600 (TA 98); 313, 625, 1250, 2500 and 5000 µg/plate (E. coli WP2 uvr A) with metabolic activation were tested in two independent experiments. Cytotoxic effects were observed in the absence of a metabolic activator at 25 µg/plate (TA 100 and TA 1537), 50 µg/plate (TA 1535 and TA 98) and in the presence of a metabolic activator (Phenobarbital- and 5,6-benzoflavone-induced rat liver S9) at concentrations of 150 µg/plate (TA 1537), 400 µg/plate (TA 100), 500 µg/plate (TA 1535) and 800 µg/plate (TA 98). No increase in the frequency of revertant colonies compared to concurrent negative controls were observed in all tested strains, neither in the presence nor in the absence of metabolic activation. Thus, Methyl laurate did not induce gene mutations in all tested strains under the given test conditions.

Genetic toxicity (cytogenicity) in mammalian cells in-vitro

CAS 111-82-0

An in vitro mammalian chromosome aberration test was performed with Methyl laurate (CAS 111-82-0) in primary human lymphocytes according to OECD Guideline 473 (Buskens, 2010). Duplicate cultures of human lymphocytes were evaluated for chromosome aberrations in the presence and absence of metabolic activation (rat liver S9-mix).

In the first experiment test substance concentrations of 33, 100 and 200 µg/mL in ethanol were used for 3 hours of exposure with and without metabolic activation. In the second experiment 100, 120 and 140 µg/mL were used for 24 hours exposure followed by 24 hours expression time and 30, 120 and 140 µg/mL for 48 hours exposure following 48 hours expression time without S9. 200 µg/mL was chosen as maximum dose due to limited solubility. Mitomycin C and cyclophosphamide were used as positive control substances. Evaluation of 100 well-spread metaphase cells from each culture for structural chromosomal aberrations revealed no increase in the frequency of chromosome aberrations and polyploid cells at any dose level in comparison to the negative controls. The test material demonstrated only modest cytotoxicity. All vehicle (solvent) controls had frequencies of cells with aberrations within the range expected for normal human lymphocytes. All the positive control materials induced statistically significant increases in the frequency of cells with aberrations indicating the satisfactory performance of the test and of the activity of the metabolising system. The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations in either the absence or presence of a liver enzyme metabolising system in either of two separate experiments. The test material was therefore considered to be non-clastogenic to human lymphocytes in vitro.

Genetic toxicity (mutagenicity) in mammalian cells in-vitro

CAS 111-82-0

An in vitro mammalian cell gene mutation assay was performed with Methyl laurate (CAS 111-82-0) according to OECD Guideline 476 in L5178Y mouse lymphoma cells (Verspeek-Rip, 2010). In the first experiment, methyl laurate was tested up to concentrations of 95 and 200 μg/mL in the absence and presence of 8% (v/v) S9-mix, respectively. The incubation time was 3 hours. Methyl laurate was tested up to cytotoxic levels of 85 and 91% in the absence and presence of S9-mix, respectively. In the second experiment, methyl laurate was tested up to concentrations of 70 and 220 μg/mL in the absence and presence of 12% (v/v) S9-mix, respectively. The incubation times were 24 hours and 3 hours for incubations in the absence and presence of S9-mix, respectively. Methyl laurate was tested up to a cytotoxic level of 90% in the absence of S9-mix and up to 88% in the presence of S9-mix. The spontaneous mutation frequencies in the solvent-treated control cultures were between the minimum and maximum value of the historical control data range and within the acceptability criteria of this assay. Mutation frequencies in cultures treated with positive control chemicals were increased by 12- and 8.4-fold for MMS in the absence of S9-mix, and by 17- and 15-fold for CP in the presence of S9-mix. In the absence of S9-mix, methyl laurate did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent repeat experiment with modifications in the duration of treatment time. In the presence of S9-mix, methyl laurate did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent repeat experiment with modifications in the concentration of the S9 for metabolic activation. It is concluded that methyl laurate is not mutagenic in the mouse lymphoma L5178Y test system under the experimental conditions described.

 

Conclusion on genetic toxicity

The available data do not provide evidence that the source substance Methyl laurate (CAS 111-82-0) exhibits mutagenic or clastogenic properties in bacteria or mammalian cells. Therefore, based on common functional groups and structural similarities, no properties for genetic toxicity are expected for Fatty acids, C18 unsaturated, ethyl & methyl esters.

 

A detailed reference list can be found in the CSR and in section 13 of the dossier.

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:
Genetic toxicity in vitro:
Ames test (OECD 471): not mutagenic (TA 1535, TA 1537, TA 98, TA 100 and E. coli Wp2 uvr A)
Chromosome aberration (OECD 473): no clastogenic (peripheral human lymphocytes)
Gene mutation (OECD 476): not mutagenic (mouse lymphoma L5178Y)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based data on the analogue read-across approach, the available data on genetic toxicity do not meet the classification criteria according to Regulation (EC) 1272/2008 and are therefore conclusive but not sufficient for classification.