Hexadecyl (R)-12-hydroxyoleate

Endpoint summary

Additional information

Justification for read-across

Data on the genetic toxicity of Hexadecyl (R)-12-hydroxyoleate (CAS 10401-55-5) are not available. The assessment was therefore based on studies conducted with analogue substances as part of a read across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. For each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements of adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

Genetic toxicity (mutagenicity) in bacteria in vitro

CAS 93803-87-3

The in vitro genetic toxicity of 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was assessed in a bacterial reverse mutation assay (Ames test), performed according to OECD 471 and in compliance with GLP (Verspeek-Rip, 1998). S. typhimurium strains TA 1535, TA 1537, TA 98 and TA 100, and E. coli WP2 uvrA were exposed to the test substance at concentrations up to 1000 µg/plate (TA 1535, TA 98 and TA 1537) and 5000 µg/plate (TA 100 and E.coli WP2 uvrA), using the plate incorporation method in two independent experiments. Precipitation was observed in the medium at 1000 µg/plate and above in all strains, with and without metabolic activation. The positive and solvent controls were shown to be valid. The test substance did not induce reversions in the S. typhimurium strains or E. coli strain, with or without metabolic activation.

CAS 3234-85-3

The in vitro genetic toxicity of Tetradecanoic acid, tetradecyl ester (CAS 3234-85-3) was assessed in a bacterial reverse mutation assay (Ames test) performed with a protocol similar to OECD 471 (Marquardt, 1994). The preincubation method was applied using S. typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 1538 in two independent experiments. Precipitation was observed in the range-finding study from 10 µg/plate for TA 98 and TA 100, and more than 50% cytotoxicity was observed in the range-finding study with TA 98 from 10 µg/plate (without metabolic activation) and with TA 100 from 1000 µg/plate (without metabolic activation). Due to the effects noted in the range-finding study, the concentration ranges tested in the main study varied per strain. The concentration ranges in the main study were: 0.1 - 10 µg/plate (TA 100, TA 1535 and TA 1538) and 0.05 – 5 µg/plate (TA 98 and TA 1537) without metabolic activation; and 10 – 1000 µg/plate (TA 100, TA 1535 and TA 1538) and 1 - 640 µg/plate (TA 98 and TA 1537) with metabolic activation. The positive and solvent controls were shown to be valid. The test substance did not induce reversions in any of the S. typhimurium strains with or without metabolic activation.

Genetic toxicity (cytogenicity) in mammalian cells in vitro

CAS 93803-87-3

The cytogenetic potential of 2-Octyldodecyl isooctadecanoate was assessed in an in vitro mammalian chromosome aberration test in primary human lymphocytes, performed according to OECD guideline 473 and under GLP conditions (Bertens, 1998). Duplicate cultures of cultured human peripheral lymphocytes were evaluated for chromosome aberrations in the presence and absence of metabolic activation. In the first experiment, cells were incubated with test substance concentrations of 100, 333 and 1000 µg/mL for 24 h and 24-h harvest time (continuous exposure) and at 1000 µg/mL for 48 h with a 48-h fixation time (continuous exposure), in the absence of a metabolic activation system. The first experiment was also performed with cells exposed to 100, 333 and 1000 µg/mL for 3 h with a 24-h fixation time and at 1000 µg/mL for 3 h with a 48-h fixation time in the presence of metabolic activation. In the second experiment, cells were incubated with 100, 333 and 1000 µg/mL for 24 h with a 24-h harvest time (continuous exposure), without metabolic activation. In the presence of metabolic activation cell were exposed to 100, 333 and 1000 µg/mL for 3 h followed by a 24-h harvest time. No cytotoxicity was observed. At 1000 µg/mL, precipitation was observed in the culture medium. The vehicle (0.9% DMSO) 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.

CAS 3687-45-4

The potential of Oleyl oleate (CAS 3687-45-4) to induce chromosomal aberrations was assessed using Chinese hamster lung fibroblast (V79) cells, in a study performed according to OECD guideline 473 and under GLP conditions (Völkner, 1994). One experiment with duplicate replications was conducted with and without metabolic activation (S9-mix). A 4-h treatment was performed without metabolic activation, using 10, 60 and 100 µg/mL concentration levels with 18-h harvest time and a 100 µg/mL concentration level with a 28-h fixation time. The treatment with metabolic activation was performed at concentrations of 10, 60 and 100 µg/mL with an 18-h treatment time and 18-h harvest time (continuous exposure), and at 100 µg/mL with a 28-h treatment time and 28-h harvest time (continuous exposure), respectively. The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations, with or without metabolic activation. Precipitation was observed at 100 µg/mL, while no cytotoxicity was noted at any concentration. The vehicle and positive controls were valid.

Genetic toxicity (mutagenicity) in mammalian cells in vitro

CAS 3687-45-4

An in vitro mammalian cell gene mutation assay was performed using Oleyl oleate (CAS 3687-45-4), according to OECD guideline 476 and under GLP conditions (Poth, 1994). Two separate experiments were performed. Chinese hamster lung fibroblast (V79) cells were treated with Oleyl oleate at concentrations of 10 - 100 µg/mL for 4 h, 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. Precipitation was seen at concentrations ≥ 100 µg/mL in a range-finsing study, and at 100 µg/mL in the main study. The positive and vehicle (ethanol) controls were valid and the results fell within the range of historical control data. No cytotoxicity was observed. No significant increase in mutation frequency was observed, with and without metabolic activation.

Overall conclusion for genetic toxicity

There are no available studies on the genetic toxicity of Hexadecyl (R)-12-hydroxyoleate in bacterial and mammalian cells. Analogue read-across from 3 source substances was applied from in vitro studies in bacterial cells, and from in vitro studies on cytogenicity and gene mutations in mammalian cells. The results of the available in vitro studies were consistently negative. Based on the available data and following the analogue approach, Hexadecyl (R)-12-hydroxyoleate is not expected to be mutagenic in bacterial and mammalian cells and clastogenic in vitro.

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 the source and target substance and overall quality assessment (refer to endpoint discussion for further details).

Short description of key information:
Ames test (OECD 471): negative with and without metabolic activation in S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 1538, and E. coli WP2 uvr A
Chromosome aberration (OECD 473): negative in cultured human peripheral lymphocytes and Chinese hamster lung fibroblasts (V79) with and without metabolic activation
Gene mutation in mammalian cells (OECD 476): negative in Chinese hamster lung fibroblasts (V79) with and without metabolic activation

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006 "General Requirements for Generation of Information on Intrinsic Properties of substances", information on intrinsic properties of substances may be generated by means other than tests e.g. from information from structurally related substances (grouping or read-across), provided that conditions set out in Annex XI are met. Annex XI, "General rules for adaptation of this standard testing regime set out in Annexes VII to X” states that “substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. This avoids the need to test every substance for every endpoint". Since the analogue concept is applied to Hexadecyl (R)-12-hydroxyoleate (CAS 10401-55-5), data will be generated from data for reference source substance(s) to avoid unnecessary animal testing. Additionally, once the analogue read-across concept is applied, substances will be classified and labelled on this basis.

Therefore, based 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.