Overview

Plastics are now being used on a large scale for the packaging of foodstuffs and beverages, both non-alcoholic and alcoholic. This is evident for all to see on the supermarket shelf, e.g., margarine packed in polystyrene (PS) tubs, wine and beer in polyvinyl chloride bottles, and bacon in polyolefin shrunk wrap films. As well as at the point of sale, foods are increasingly shipped in bulk in plastic containers. Additionally there is the area of the increasing use of plastic utensils and containers in both the home and during the bulk preparation of food in restaurants, canteens, and food factories. Contact between plastics and packaged substances also occurs in the products of the pharmaceutical and cosmetics industries.

Where direct contact occurs between the packed commodity and the plastic it is likely that some transfer of polymer additives will occur, adventitious impurities such as monomers, catalyst remnants, and residual polymerisation solvents, and low molecular weight (MW) polymer fractions from the plastic into the packaged material with the consequent risk of a toxic hazard to the consumer. The actual hazard arising to the consumer from any extractable present is a function of two properties, namely the intrinsic toxicity of the neat extracted material as evaluated in animal feeding trials (not dealt with in this book) and the amount of the extracted material from the polymer that enters the packed food under service conditions, i.e., during the packaging operation and during the shelf life of the food to the time of consumption.