Migration Potential from Plastic Food Contact Materials Case Study : Stretch Films

Abstract

            Eight samples of stretch films of different brand names widely available in Thailand and one sample from Japan were studied. The thickness of all samples is 0.01 mm. The plastic identification by flame test and by using FTIR has shown that the samples are different in nature : Best Wrap and Clean Wrap are linear low density polyethylene (LLDPE); Fresh Wrap, Fit Wrap, Good Wrap, M Wrap, and Riken Wrap are polyvinyl chloride (PVC); Glad Wrap and Saran Wrap are Polyvinylidene chloride (PVDC). The amounts of potential migrants extracted by the rapid extraction test are different (p<0.01) from those obtained from the ultrasonication extraction. The former method is in principle permitted in the EU Practical Guide Nr.1 and the FDA Recommendations for Chemistry Data, while the latter has just been proposed as an alternative method owing to less effort and expense required. The approval of this method is still under investigation. However, the amounts of potential migrants extracted by both methods from all samples of LLDPE and PVDC do not exceed the EU global migration limit of 10 mg/dm², whereas those of PVC do. Therefore, in this case, it will be necessary to carry out further migration tests.

             The identification of the extracts by using proton nuclear magnetic resonance (H-NMR) has been studied. According to the spectrum of the extracts, it could be suggested that the potential migrants in these
stretch films are as follows: monomer and oligomer in LLDPE samples; adipate, ester of adipic acid, in PVDC and PVC samples, except Fresh Wrap in which phthalate has been found.