Migration of inorganic contaminants into dry food from packaging made from recycled paper and board.

A radiotracer method was applied to the measurement of inorganic contaminants migrating into food. The method was applied to the study of 10 samples of recycled paper and board. The only elements detected in the static migration test were zinc and iron, at concentrations close to the detection limit. Samples of rice, oats, custard powder, mushrooms and fries showed that traces of these elements had migrated from the packaging. The migration was limited to less than 1%, with the exception of the mushrooms, where the decomposition of the food had resulted in a 12.5% transfer of zinc from the mushroom bag after 8 days, equivalent to migration of 0.022 mg dm(-2). Shaking had no effect on migration, except in one case of custard powder where migration occurred at a level equivalent to 0.002 mg dm(-2). The maximum migration determined in the present study was 4.8 microg zinc and 2.6 microg iron, which is negligible when compared with the recommended daily intakes of 15 and 14 mg, respectively. When Tenax was tested as a food simulant, no zinc was detected (< 0.001 mg dm(-2)), although slight migration (0.001 mg dm(-2)) occurred into food.