Content of SDs and STs in PS Food Containers

According to our investigations, the contents of SD and STs in disposable lunch boxes differ with each product [8]. The analyzed samples were disposable lunch boxes from the market and boxes containing convenience foods and lunches. Previously, most of these lunch boxes were made of PS only, but recently have gradually changed to polypropylene (PP). Table 31.2 shows the levels of compounds found in various kinds of disposable lunch boxes. 

8 1 a-Phenyl-4a-( 1 -phenylethyl)tetralin (T-3b) 1 e-Phenyl-4a-( 1 -phenylethyl)tetralin 91.207 

There are certain kinds of PS that are used in food containers, such as general-purpose PS (GPPS), high-impact PS (HIPS), EPS and PS paper (PSP). In these studies, the content of SDs and STs did not always depend on the type of PS. However, in other studies investigating various types of PS containers for instant foods, the contents of SDs and STs in EPS, for example, Chinese noodles Nos 1-3 and soup Nos 1-5, showed were very low (Table 31.4). The sum of SDs and STs ranged from 60 to 130 and from 370 to 680 jxg/g, respectively. As polymerization of EPS is a low-temperature reaction, it was expected that only traces of by-products of polymerization would remain [6]. 

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