Determination of the migration amount and total amount of styrene monomer, dimers and trimers in polystyrene food containers by GC/MS

Abstract

Plastic containers for food must be made in accordance with the Food Sanitation Laws,and there are migration standards for particular components. However, there no standards have been set for the styrene monomer, dimers and trimers. The dimers and trimers have been selected as potential environmental endocrine disrupters by the Environment Agency. We investigated the actual migration amounts of the styrene monomer,dimers (4 substances) and trimers (5 substances) for several solvents on commonly used food containers, such as commercial instant-noodle containers (6 samples), disposable plastic cups (5 samples) and convenience-store lunch containers (2 samples). The experimental results were as follows: with n-heptane, the dimers were found at concentrations of 15.6-745 ppb and the trimers at 208-6110 ppb; when the solvent was 20% ethanol,the styrene monomer was measured at 0.11-1.5 ppb, the dimers at concentrations of 0.353-4.86 ppb, and the trimers at 0.892-9.87 ppb; and when the solvent was water, the styrene monomer was 0.14-2.6 ppb, the dimers were 0.035-1.291 ppb, and the trimers were N.D.-2.666 ppb. We also investigated the total amounts of the dimers and trimers included in the plastic containers. The dimers and trimers were measured at levels from 171 to 426 ppm and from 3260 to 12800 ppm, respectively.