Abstract: Provided are metal detectable plastic bags, method of making and methods of using such bags for preventing product contamination when used to collect and retain samples of product. The metal detectable plastic bag includes a flexible body including an opposed front wall and back wall sealed together around the periphery of the walls to form an internal collection space including two side seal areas, a top seal area and a bottom seal area, a bag opening mechanism located proximate a top edge of the flexible body and below the top seal area. The bag opening mechanism includes one or more perforations, scores or cuts in the one or two side seal areas and optionally the front and back wall to form a removable tear strip. At least a portion of the removable tear strip is surface printed with a metallic based ink or surface coated with a metallic based coating.