Isooctyl acrylate

Endpoint summary

Additional information

Three studies have been conducted: An Ames Assay, a Chromosome Aberration study and a Mouse Lymphoma assay.

In the Chromosome aberration study, MTDID 7819 did not induce a statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in the absence of S9-mix at the 3 hour and 24 hour exposure times and in the presence of S(-mix, in the first and second cytogenetic assays. However, in the second cytogenetic assay in the absence of S9-mix at the 48-hour exposure time, MTDID-7819 induced a statistically significant increase in the number of cells with chromosome aberrations at the highest, cytotoxic concentration, both when gaps were included and excluded. Because this increase was above the historical control data range, observed in both duplicate cultures it was considered biologically relevant and MTDID-7819 was considered clastogenic.

No effects of MTDID-7819 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 MTDID-7819 does not disturb mitotic processes and cell cycle progression and does not induce numerical chromosome aberrations under the experimental conditions described in the report.

In the Mouse Lymphoma study, the test article was tested in the presence and absence of exogenous metabolic activation by Aroclor induced rat liver S-9 in the L5178Y TK+/- Mouse Lymphoma Mutagenesis Assay. Although some of the test cultures exhibited mutant frequencies which were two fold greater than the average mutant frequency of the corresponding solvent control, no dose response was seen and the mutant frequencies were within the range of experimental error (mutant frequencies similar to those for solvent controls for the positive controls). The test article was therefore considered negative in the assay under the test conditions.

In the Ames Salmonella/microsome assay, Compound T-2476ChR was tested initially in a preliminary assay with S. typhimurium strain TA100 over a wide range of concentrations, from 0.01 to 5.0 ul/plate Pinpoint colonies (indicating toxicity) appeared at 5.0 ul/plate, so the concentration range was lowered to 0.0005 to 0.5 ul/plate in subsequent tests using all five strains of S. typhimurium. At 0.5 ul/plate, the test compound was toxic with TA100, but no dose-related increase in the number of revertants per plate was observed in either assay.

In the microbiological assays with S. cerevisiae D3, T-2476ChR was initially tested over a wide range of concentrations, from 0.01 to 5.0%. Toxicity was observed at all concentrations so the range was lowered to 0.00005 to 0.05% for subsequent testing. No dose-related increase in the number of mitotic recombinants above background was observed.

The test material, T-2476ChR was negative in this assay.

Endpoint Conclusion:

Justification for classification or non-classification

The criteria for classification were not met.