5, 39.1, 78.1, 156, 313, 625, 1250, 2500, and 5000 μg/mL. No cytotoxicity was observed at any concentration under any condition, but precipitation Selleck CH5424802 of the test substance was observed at concentrations of 1250 μg/mL or greater. Therefore, only concentrations of 1250, 2500, and 5000 μg/mL were used in the in vitro chromosomal aberration test. Relative cell growth rate was greater than 68% and no cytotoxicity was detected for all concentrations at all treatment conditions (Table 4). Precipitation of the test substance was detected at all three doses examined. The percentages of cells with structural

aberrations or numerically aberrant cells were below 3% at all concentrations and for all treatment conditions; therefore, the in vitro chromosomal http://www.selleckchem.com/products/Rapamycin.html aberration test was considered negative for both structural and numerical aberrations.The frequencies of cells with structural aberrations in the negative and positive controls, and the frequencies of numerically aberrant cells in the negative control, were all within the historical range for our laboratory (data not shown). There are few reports in the literature presenting evaluations of the genotoxicity of styrene oligomers. Grifoll et al. [12] reported a negative Ames test; however, their study examined only one tester strain (S. typhimurium strain TA98)

under conditions of metabolic activation by the microsomal fraction of the livers of male Sprague Dawley rats induced with Aroclor® 1254. Therefore, the potential for extrapolating those results to Acetophenone determine the genotoxic effects of styrene oligomers on human health is limited. Thus, to contribute to the risk assessment of styrene oligomers migrated from polystyrene food packaging into food, in the present study we carried out the genotoxicity tests required by the FDA and EFSA for the safety evaluation of food packaging by using a concentrated solution of

oligomers extracted from polystyrene intended for use in contact with food. The migration of SDs and STs from polystyrene food packaging to food was investigated by Kawamura et al. [17] and [18] and Nakada et al. [19]. The migration of SDs and STs to foods such as instant noodles under general use conditions has been investigated and compared with the concentrations of SDs and STs extracted with organic solvents [18]. The migration of SDs and STs to food can be as high as approximately 50 ppb [19], whereas the concentrations of SDs and STs extracted with 50% ethanol solution can be as high as 70 ppb (Table 5; [17], [18] and [19]). The FDA recommends using 50% ethanol as a high-fat food simulant when examining the safety of polystyrene [3] and the EFSA recommends as milk products out of high-fat food simulant [11].