STUDIES ON CONTAMINATION OF POST CONSUMER PLASTICS FROM CONTROLLED RESOURCES FOR RECYCLING INTO FOOD-PACKAGING APPLICATIONS

Recycled materials reclaimed from controlled used food packaging mater ial of the polymer types HDPE, PP, PS and PET were investigated with r espect to their constituents. The study was designed as a comparison b etween virgin and recycled material to detect and identify recycling s pecific substances. As a general result, qualitatively and quantitativ ely, only a few contaminants were found. According to the intrinsic di ffusivity of the investigated polymers, the impurification grade incre ased from PET to PS and to PP and HDPE. Most of the detected contamina nts are aroma compounds and can therefore be linked with the foodstuff s contained in the package at the first usage. Furthermore, other cont aminants like phthalates and paraffins were detected which are known a s widespread impurifications. But they can have also entered the mater ial by commingling with other polymers. In the odour test all recyclin g materials were identified because of their slight musty smell. For a dh rct food contact these materials would not be in compliance with t he food laws. For an indirect use, e.g. buried by a virgin layer, the contamination risk of foodstuffs can be excluded applying the availabl e knowledge of migration theory. In order to control the migration out of such materials at threshold-of-regulation concept is desirable, an alogous to the corresponding FDA regulation.