Phenol, C14-18-alkyl derivs.

Endpoint summary

Additional information

In vitro

Three key studies are available to address the in vitro genetic toxicity of the test material. All were awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

 

The mutagenic activity of the test material was evaluated in a bacterial reverse mutation assay conducted in accordance with the standardised guidelines OECD 471 and EU Method B.13/14 under GLP conditions.

The test material was tested with four histidine-requiring strains of Salmonella typhimurium (TA1535, TA1537, TA98 and TA100) and with a tryptophan-requiring strain of Escherichia coli (WP2uvrA). The test was performed in two independent experiments in the presence and absence of S9-mix (rat liver S9-mix induced by Aroclor 1254).

The dose levels in the first experiment were 17, 52, 164, 512, 1600 and 5000 µg/plate, and the dose levels in the second experiment were 492, 878, 1568, 2800 and 5000 µg/plate. The test material was dissolved in ethanol.

In a dose range finding test, the test material was tested up to the concentration of 5000 µg/plate in the absence and presence of 5 % (v/v) S9-mix in the strains TA100 and WP2uvrA. The test material precipitated on the plates at dose levels of 1600 and 5000 µg/plate. The bacterial background lawn was not reduced at any of the concentrations tested and no decrease in the number of revertants was observed. Results of this dose range finding test were reported as part of the first mutation assay.

Based on the results of the dose range finding test, the test material was tested in the first mutation assay in the absence and presence of 5 % (v/v) S9-mix in tester strains TA1535, TA1537 and TA98. The test material precipitated (observed as droplets) on the plates at dose levels of 1600 and 5000 µg/plate. The bacterial background lawn was not reduced at any of the concentrations tested and no biologically relevant decrease in the number of revertants was observed.

In a follow-up experiment of the assay with an increased amount of S9-mix, the test material was tested in the absence and presence of 10 % (v/v) S9-mix in tester strains TA1535, TA1537, TA98, TA100 and WP2uvrA. The test material precipitated (observed as droplets) on the plates at dose levels of 2800 and 5000 µg/plate. The bacterial background lawn was not reduced at any of the concentrations tested and no biologically relevant decrease in the number of revertants was observed.

The negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

Under the conditions of this study, the test material was determined to be non-mutagenic in both the presence and absence of metabolic activation.

 

The ability of the test material to induce chromosome aberrations in cultured peripheral human lymphocytes was evaluated in a study conducted in accordance with the standardised guidelines OECD 473 and EU Method B.10 under GLP conditions.

The study investigates the effect of the test material on the number of chromosome aberrations in cultured peripheral human lymphocytes in the presence and absence of a metabolic activation system (phenobarbital and ß-naphthoflavone induced rat liver S9-mix).

Experiments were carried out in duplicate and concurrent solvent (ethanol) and positive controls took place.

The dose levels tested were as follows:

- Range-finding test: 0.54, 1.7, 5.4, 17, 52, 164 and 512 µg/mL (without metabolic activation; 24 hour exposure time, 24 hour fixation time; 48 hour exposure time, 48 hour fixation time)

- First cytogenetic assay: 5.4, 17 and 52 µg/mL (with and without metabolic activation; 3 hour exposure time, 24 hour fixation time)

- Second cytogenetic assay: 10, 30, 40, 50, 60 and 70 µg/mL (without metabolic activation; 24 hour exposure time, 24 hour fixation time; 8 hour exposure time, 48 hour fixation time)

In the first cytogenetic assay, the test material precipitated in the culture medium at 52 µg/mL. In the second cytogenetic assay, appropriate toxicity was reached at the dose levels.

The test material did not induce any statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in the absence and presence of S9-mix, in either of the two independently performed experiments.

No effects of the test material on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Therefore it can be concluded that the test material does not disturb mitotic processes and cell cycle progression and does not induce numerical chromosome aberrations under the experimental conditions used.

The number of cells with chromosome aberrations found in the solvent control cultures was within the laboratory historical control data range. The positive controls both produced a statistically significant increase in the incidence of cells with chromosome aberrations, indicating that the test conditions were adequate and that the metabolic activation system (S9-mix) functioned properly.

Under the conditions of this study the test material is not clastogenic in human lymphocytes with and without metabolic activation.

 

The mutagenic activity of the test material was evaluated in an in vitro mammalian cell gene mutation test with L5178Y mouse lymphoma cells. The study was conducted in accordance with the standardised guidelines OECD 476 and EU Method B.17 under GLP conditions.

The study investigated the effects of the test material on the induction of forward mutations at the thymidine-kinase locus (TK-locus) in L5178Y mouse lymphoma cells. The test was performed in the absence of S9-mix with 3- and 24-hour treatment periods and in the presence of S9-mix with a 3 hour treatment period (rat liver S9-mix induced by a combination of phenobarbital and ß-naphthoflavone). Concurrent solvent (ethanol) and positive controls took place.

In the first experiment, the test material was tested up to concentrations of 500 and 80 µg/mL in the absence and presence S9-mix, respectively. The incubation time was 3 hours. The Relative total growth (RTG) was reduced to 7 % in the presence of S9-mix. No obvious toxicity was observed up to and including dose levels of 500 µg/mL in the absence of S9-mix; however, the test material precipitated in the culture medium at dose levels of 100 µg/mL and above.

In the second experiment, the test material was tested up to concentrations of 60 µg/mL in the absence of S9-mix. The incubation time was 24 hours. The RTG was reduced to 6 %.

In the absence of S9-mix, the test material did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent experiment with modification in the duration of treatment.

In the presence of S9-mix, the test material did not induce a significant increase in the mutation frequency.

The spontaneous mutation frequencies in the solvent-treated control cultures were within 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 10- and 8.7-fold for methyl methanesulfonate in the absence of S9-mix, and by 22-fold for cyclophosphamide in the presence of S9-mix. In addition the observed mutation frequencies of the positive control materials were within the acceptability criteria of this assay. It was therefore concluded that the test conditions, both in the absence and presence of S9-mix, were appropriate and that the metabolic activation system (S9-mix) functioned properly.

Under the conditions of this study the test material is not mutagenic in the presence and absence of metabolic activation.

Justification for selection of genetic toxicity endpoint
No single key study was selected on the basis that the available studies all address different aspects of genetic toxicity and the data should be considered as a whole. All three studies were conducted in accordance with standardised guidelines under GLP conditions.

Short description of key information:
IN VITRO
- Non mutagenic with and without metabolic activation (Ames test); OECD 471 and EU Method B.13/14
- Non clastogenic with and without metabolic activation (chromosome aberration test); OECD 473 and EU Method B.10
- Non mutagenic with and without metabolic activation (mouse lymphoma assay); OECD 476 and EU Method B.17

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No. 1272/2008, the substance does not require classification with respect to genetic toxicity.