Isononanoic acid, C16-18 (even numbered)-alkyl esters

Endpoint summary

Additional information

Justification for grouping of substances and read-across

There are only limited data available on the genetic toxicity of isononanoic acid, C16-18 alkyl esters (CAS 111937-03-2). In order to fulfil the standard information requirements set out in Annex VII and VIII, 8.4, 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 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).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 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.

Overview of genetic toxicity

CAS	Chemical name	Molecular weight (range)	Genetic toxicity (mutagenicity) in vitro, bacteria	Genetic toxicity (cytogenicity) in vitro, mammalian cells	Genetic toxicity (mutagenicity) in vitro, mammalian cells	Genetic toxicity in vivo
111937-03-2 (a)	Isononanoic acid, C16-18 alkyl esters	382.66; 410.72	WoE: Experimental result: not mutagenic RA: CAS 59130-69-7	RA: CAS 26399-02-0 RA: CAS 3687-45-4	RA: CAS 26399-02-0 RA: CAS 3687-45-4	RA: CAS 135800-37-2
135800-37-2 (b)	Fatty acids, C8-16, 2-ethylhexyl esters	256.42-368.63	Experimental result: not mutagenic	--	--	Experimental result: not clastogenic
26399-02-0	2-ethylhexyl oleate	394.67	--	Experimental result: not clastogenic	Experimental result: not mutagenic	--
59130-69-7	Hexadecyl 2-ethylhexanoate	368.63	Experimental result: not mutagenic	--	--	--
3687-45-4	(Z)-octadec-9-enyl oleate	532.92	--	Experimental result: not clastogenic	Experimental result: not mutagenic	--

(a) Substances subject to the REACh Phase-in registration deadline of 31 May 2013 are indicated in bold font.

(b) Substances that are either already registered under REACh or not subject to the REACh Phase-in registration deadline of 31 May 2013 are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

The above mentioned substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information is used to predict the same endpoints for isononanoic acid, C16-18 alkyl esters (CAS 111937-03-2). A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

 

Discussion

Gene mutation in bacteria in vitro

CAS 111937-03-2

The in-vitro genetic toxicity of isononanoic acid, C16-18 alkyl esters (CAS 111937-03-2) was assessed in a bacterial reverse mutation assay (Ames test) performed similarly to OECD 471 (Banduhn, 1988). The plate incorporation method was applied using S. typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 1538 at concentrations up to 5000 µg/plate. No cytotoxic effects were observed and all positive controls were valid. The test substance did not induce reversions in any of the S. typhimurium strains with or without metabolic activation.

CAS 59130-69-7

The in vitro genetic toxicity of hexadecyl 2-ethylhexanoate (CAS 59130-69-7) was analyzed in abacterial reverse mutation assay (Ames test)performed according to OECD 471 (Haddouk, 2007). The bacteria strains S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102 were treated with concentrations of 312.5, 625, 1250, 2500 and 5000 µg/plate hexadecyl 2-ethylhexanoate with and without metabolic activation (S9-mix).No cytotoxic effects were observed and all positive controls were valid. The test substance did not induce reversions in any of the S. typhimurium strains with or without metabolic activation.

Cytogenicity in vitro

CAS 26399-02-0

The cytogenetic potential of 2-ethylhexyl oleate (CAS 26399-02-0) was assessed in an in vitro mammalian chromosome aberration test in primary human lymphocytes, performed 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, cells were incubated with test substance concentrations of 3, 10 and 33 µg/mL in ethanol for 3 hours with and without metabolic activation. In the second experiment cells were incubated with 3, 10 and 33 µg/mL for 24 hours followed by 24 hours expression time and 48 hours following 48 hours expression time, all without metabolic activation. 33 µg/mL was chosen as maximum concentration due to limited solubility of the test substance. 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. The vehicle (solvent) and positive controls were shown to be valid. The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations with or without metabolic activation. The test substance was therefore considered to be non-clastogenic to human lymphocytes in vitro.

CAS 3687-45-4

The potential of oleyl oleate (CAS 3687-45-4) to induce chromosomal aberrations was assessed using Chinese hamster V79 cells, in a study performed according to OECD 473 (Völkner, 1994). The V79-cells were exposed to oleyl oleate at concentrations up to 100 µg/mL, with and without metabolic activation (S9-mix). One experiment with duplicate replications was performed with short-term treatment (4 h) and fixation time 18 and 28 h, without metabolic activation; and with metabolic activation using 18 h treatment time and 18 h fixation time and 28 h treatment time and 28 h fixation time, respectively. The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations, with or without metabolic activation. The mitotic indices of the treated cultures without metabolic activation were 83.4-119% and with metabolic activation 91-127.1%, compared with the vehicle control. Precipitation was observed at concentrations from 100 µg/mL, while no cytotoxicity was noted at any concentration. The vehicle and positive controls were valid.

Gene mutation in mammalian cells in vitro

CAS 26399-02-0

An in vitro mammalian cell gene mutation assay was performed with 2-ethylhexyl oleate (CAS 26399-02-0) according to OECD 476 (Verspeek-Rip, 2010). Two independent experiments (with 3 or 24 hours of exposure) were performed in mouse lymphoma L5178Y cells in the absence and presence of metabolic activation (S9-mix) with test substance concentrations up to 100 μg/mL dissolved in ethanol. Precipitation was seen at 100 µg/mL and higher. The positive and negative controls were valid and within the range of historical control data. No significant increase in mutation frequency occurred in any of the test conditions.

CAS 3687-45-4

An in vitro mammalian cell gene mutation assay was performed using oleyl oleate (CAS 3687-45-4), according to OECD 476 (Poth, 1994). Chinese hamster lung fibroblasts (V79) were treated with oleyl oleate at concentrations of up to 100 µg/mL for 4 h both with and without metabolic activation. After an expression time of 7 days in growth medium, cells were incubated for 9 or 12 days with 6 -thioguanine as selection agent for forward mutation at the HPRT locus. Both with and without metabolic activation, no increases in mutant frequency were observed in the initial and in the confirmatory gene mutation assay. There was no evidence of excessive cytotoxicity (i.e., < 10 % relative cloning efficiency) at any of the tested concentrations either in the presence or absence of metabolic activation in any of the experiments performed.

Genetic toxicity in vivo

CAS 135800-37-2

The ability ofFatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2)to induce chromosome aberrations in vivo in mouse bone marrow cells was tested according to OECD guideline 474 and GLP (Paika, 1991). Male and female mice were treated with 0, 1075, 2150 and 4300 mg/kg bw test substance by single intraperitoneal injection and sacrificed for examination at 24 h intervals for up to 72 hours. Cyclophosphamide was used as a positive control. The mouse micronucleus test did not reveal increases in the frequency of micronucleated polychromatic erythrocytes in the treated animals and therefore no indications of induced chromosome damage were found.

Conclusions for genetic toxicity

The available data onisononanoic acid, C16-18 alkyl esters (CAS 111937-03-2) and several surrogate substances showed that the results of all in vitro and in vivo genetic toxicity studies performed in bacteria and mammalian cells with and without metabolic activation were negative (Banduhn, 1988; Buskens, 2010;Haddouk, 2007;Paika, 1991; Poth, 1994; Verspeek-Rip, 2010; Völkner, 1994).

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within CSR.

Justification for selection of genetic toxicity endpoint
Hazard assessment is conducted by means of read-across from structural analogues. 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:
Mutagenicity in bacteria (OECD 471): negative (based on substance-specific study and on read-across from CAS 51930-69-7)
Cytogenicity in mammalian cells in a chromosome aberration test (OECD 473): negative (based on read-across from CAS 3687-45-4 and CAS 26399-02-0)
Mutagenicity in mammalian cells in a MLA and HPRT assay (OECD 476): negative (based on read-across from CAS 26399-02-0 and CAS 3687-45-4)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on substance-specific data and read-across from the structurally similar substances, the available data on genetic toxicity 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.