Hexanoic acid, 2-ethyl-, C16-18-alkyl esters

Endpoint summary

Additional information

Justification for grouping of substances and read-across

There are no data available for the genetic toxicity of Hexanoic acid, 2-ethyl, C16-18 alkyl esters (CAS No. 90411-68-0). In order to fulfil the standard information requirements set out in Annex IX in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted.

In accordance with 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, 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).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, 1.5, of Regulation (EC) No 1907/2006, whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

Genetic toxicity

CAS	90411-68-0	95912-86-0	59130-69-7	26399-02-0	111937-03-2
Chemical name	Hexanoic acid, 2-ethyl, C16-18 alkyl esters	Fatty acids, C8-10, C12-18-alkyl esters	Hexadecyl 2-ethylhexanoate	2-Ethylhexyl oleate	Isononanoic acid, C16-18 alkyl esters
MW	368.6-396.7 g/mol	312.53-424.74 g/mol	368.6 g/mol	394.7 g/mol	382.66-410.72 g/mol
Genetic Toxicity in vitro: gene mutation in bacteria	RA: CAS 59130-69-7	Experimental result: negative	Experimental result: negative	-	Experimental result: negative
Genetic Toxicity in vitro: cytogenicity in mammalian cells	RA: 26399-02-0	-	-	Experimental result: negative	-
Genetic Toxicity in vitro: gene mutation in mammalian cells	RA: 26399-02-0	-	-	Experimental result: negative	-

 

The above mentioned substances are considered to be similar on the basis of the structural similarity resulting in similar properties and/or activities. The available endpoint information is used to predict the same endpoints for Hexanoic acid, 2-ethyl, C16-18 alkyl esters (CAS No. 90411-68-0).

A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Discussion

Genetic toxicity in vitro

In vitro gene mutation in bacteria

There are no data available on the in vitro mutagenic potential ofHexanoic acid, 2-ethyl, C16-18 alkyl esters in bacteria.In order to fulfil the standard information requirements set out in Annex IX in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5 read-across from the structurally related analogue substanceshexadecyl 2-ethylhexanoate, Fatty acids, C8-10, C12-18-alkyl esters, and Isononanoic acid, C16-18-alkyl estersis conducted.

Gene mutation in bacteria by hexadecyl 2-ethylhexanoate was analysed in a GLP study performed according to OECD guideline 471 (Haddouk, 2007). Bacteria strains S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102 were treated with the test substance diluted in ethanol at concentrations of 312.5, 625, 1250, 2500, 5000 µg/plate with and without metabolic activation. As no increase in revertant colonies was noted in any strain and concentration, the test substance was considered to be not mutagenic under the conditions applied.

In another Ames test performed to GLP and equivalent to OECD guideline 471, the structural analogue Fatty acids, C8-10, C12-18-alkyl esters was tested in S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 1538 (Banduhn, 1989). No tester strain able to detect cross-linking was used in this test. In the first experiment the bacteria were treated with concentrations of 8, 40, 200, 1000 and 5000 µg/plate diluted in Tween80/aqua bidest without metabolic activation and with concentrations of 16, 80, 400, 1000 and 5000 µg/plate with metabolic activation. Concentrations of 8, 40, 200, 1000 and 5000 µg/plate with and without metabolic activation were used in the second experiment. Although cytotoxicity was observed at the highest dose, no increase in revertant colonies was found. Fatty acids, C8-10, C12-18-alkyl esters was considered to be not mutagenic under the conditions applied.

The same negative result was found in a similar study by the same author in accordance to GLP and OECD guideline 471 with another structural analogue substance, Isononanoic acid, C16-18-alkyl esters (Banduhn, 1988). Bacteria S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100 were treated with diluted test substance (Tween 80/water) at concentration of 8, 40, 200, 1000 and 5000 µg/plate, with and without metabolic activation. Since no increase in revertant colonies was noted, the analogue substance Isononanoic acid,C16-18-alkyl esters was considered to be not mutagenic under the conditions applied.

In vitro cytogenicity

There are no data available on the in vitro cytogenic potential ofHexanoic acid, 2-ethyl, C16-18 alkyl esters in bacteria.In order to fulfil the standard information requirements set out in Annex IX in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5 read-across from the structurally related analogue substanceshexadecyl 2-ethylhexanoateis conducted.

The structural analogue 2-ethylhexyl oleate was tested in an in vitro mammalian chromosome aberration test with cultured peripheral human lymphocytes performed in accordance to OECD guideline 473 (Buskens, 2010). The test substance was applied as a dilution (vehicle: ethanol) at concentration of 3, 10 and 33 µg/mL to the cultured lymphocytes in the presence and absence of metabolic activation. Both in the absence and presence of S9-mix ethylhexyl oleate did not induce a statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in two independent experiments. No effects on the number of polyploid cells and no increase in cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Thus, ethylhexyl oleate did not disturb mitotic processes and cell cycle progression and did not induce numerical chromosome aberrations under the experimental conditions described.

In vitro gene mutation in mammalian cells

There are no data available on the in vitro mutagenic potential ofHexanoic acid, 2-ethyl, C16-18 alkyl esters in mammalian cells.In order to fulfil the standard information requirements set out in Annex IX in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5 read-across from the structurally related analogue substanceshexadecyl 2-ethylhexanoateis conducted.

Gene mutation in mammalian cells is assessed in a study with the structural analogue 2-ethylhexyl oleate, which was tested in a GLP study performed according to OECD guideline 476 (Verspeek-Rip, 2010). Mouse lymphoma L5178Y cells were treated with concentrations of 0.03, 0.1, 0.3, 1, 3, 10, 33, and 100 µg/mL for 3 or 24 h with and without metabolic activation. As result, no significant increase in the mutation frequency in the presence or absence of S9-mix was found, independent of incubation time or composition of the S9 mix. Thus, 2-ethylhexyl oleate did not induce gene mutation in mammalian cells under the condition of the test.

Conclusion

No data are available for assessment of genetic toxicity with Hexanoic acid, 2-ethyl-, C16-18 alkyl esters. Data from the analogue substances Fatty acids, C8-10, C12-18-alkyl esters, Hexadecyl 2-ethylhexanoate,Isononaoic acid, C16-18 alkyl estersand Isononanoic acid, C16-18 alkyl esters indicate no potential for genetic toxicity in vitro.In conclusion, the available data on genetic toxicity in vitro ofHexanoic acid, 2-ethyl-, C16-18 alkyl estersand structural analogue substances indicate thatHexanoic acid, 2-ethyl-, C16-18 alkyl estersis not genotoxic in vitro.

 

Justification for selection of genetic toxicity endpoint
Hazard assessment is conducted by means of read-across from a structural analogue. No study was selected, since all available in vitro genetic toxicity studies were negative. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substance and overall quality assessment (refer to the endpoint discussion for further details).

Short description of key information:
In vitro:
Gene mutation (Ames test): S. typhimurium TA 1535, TA 1537, TA 98, TA 100, and TA 102: negative with and without metabolic activation (according to OECD TG 471)
Mammalian cytogenicity (chromosome aberration): peripheral human lymphocytes: negative (OECD TG 473)
Mammalian mutagenicity (MLA): negative with and without metabolic activation (OECD TG 476)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available data on genetic toxicity of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.