Ethyl acetate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Bacterial mutagenicity: negative with and without metabolic activation.
Cytogenicity: negative with and without metabolic activation.
Mammalian cell gene mutation: negative with and without metabolic activation.

Genetic toxicity in vivo

Description of key information

Mouse micronucleus in vivo: negative

Additional information

There is clear evidence to indicate that ethyl acetate is not mutagenic in in vitro bacterial or yeast test systems, with or without metabolic activation. There is no data using ethyl acetate on a strain of bacteria with an AT base pair at the primary reversion site that is capable of detecting certain mutagens and cross-linking agents, such as E.coli WP2 or TA102. There is such a test in ethanol. The rapid in vivo hydrolysis of ethyl acetate to ethanol allows data from the latter to be used as a surrogate to predict the toxicity of ethyl acetate to systemic end point such as fertility. A full justification for such a read across is attached as a report in chapter 13. Ethanol was negative in a DNA repair test using E. coli WP2.

In vitro chromosome aberration assays have yielded mixed results. Negative findings were reported in Chinese Hamster ovary cells in a conventional chromosome abberation study, although the same authors reported equivocal to small increases in sister chromatid exchange with S9 activation and higher doses. Another study reported a marginally positive chromosome abberation assay in Chinese hamster lung fibroblasts at much higher concentrations (up to 9.0 mg/ml). These weak positive results need to be interpreted in the context of the very high concentrations at which they were obtained, which were well above normal recommended maxima. The negative results at lower concentrations are more likely to be indicative of the actual cytotoxicity of this substance under more relevant conditions. However, these should be put into context against the in vivo data; ethyl acetate did not induce micronuclei in three well-conducted in vivo bioassays. In these studies, either hamsters received single doses of ethyl acetate by intraperitoneal injection (473 mg/kg/bw) or gavage (2500 mg/kg/bw) and mice received a single 800 mg/kg/bw dose of ethyl acetate by intraperitoneal injection, or up to four doses of 200 mg/kg/bw each.

There is no mammalian cell mutation study available using ethyl acetate. However, in a study using mouse lymphoma lymphoma cells in the TK forward mutation assay, ethanol was found to be non mutagenic with and without metabolic activation at very high doses up to and including those that cause significant cytotoxicity (typically in the region 0.3 -0.5M.

In a review of the genotoxicity of ethanol, the results from using ethanol as a vehicle in multiple in vitro guideline mammalian gene mutation assay was reported. As a control vehicle, ethanol was used in the guideline tests at a dose of 1%, well in excess of the maximum dose normally recommended for use. The mean, minimum and maximum mutation frequencies for the ethanol vehicle control plates were all comparable to the pooled results from 20 previous vehicle controls used at the laboratory, Since ethanol is the rapid in vivo metabolite of ethyl acetate this result can be used to confidently predict that ethyl acetate will also show a similar negative mutagenic response.

Aneuploidy has been reported in yeast assays by a number of investigators at ethyl acetate concentrations exceeding 2% but negative results have been reported at concentrations up to 1.72%. The relevance of positive findings in this test system for mammals in vivo, however, remains unclear, but is not likely to be of practical significance.

In summary, mixed results were obtained in the in vitroassays for clastogenicity, including some weak positive results but only at very high dose levels. However, negative results were obtained in multiple in vivo bone marrow assays for clastogenicity (micronucleus test) using high dose levels (administered ip). In addition the metabolites ethanol and acetic acid do not have any significant mutagenic potential. Overall, genotoxicity is not considered a significant property of ethyl acetate.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

No classification is proposed based on the most reliable animal data. The data as a whole indicates that genotoxicity is not a significant property of ethyl acetate and that classification according to the criteria is not warranted.