Metal packaging and chemical migration into food

Metal packaging and chemical migration into food 

For this reason harmonised EU legislation that includes metal foodstuff packaging is needed. Extension of the existing harmonised legislation on plastics materials and articles is not appropriate without significant 

A common factor of metal foodstuff packaging is that it provides long term ambient stable storage with excellent abuse resistance and protection from environmental contamination ensuring food safety and quality retention with extended shelf life. Flexible packaging which is covered elsewhere in this book may also use thin layers of metal either as discrete foil layers or as metallised plastic or paper layers for improved barrier properties, but the main structural components are non-metallic and so are not covered here. 

The metals used to manufacture cans, ends and closures are either steel (tin plated or chromium passivated) or aluminium. In most cases they are coated on the food contact surface with a resinous or polymeric protective coating to avoid interaction between the foodstuff and the metal. However, there is a well defined sector of the tinplate food packaging market where no protective organic coating is needed or used. 

Cans may either be three piece consisting of a body made up of a welded cylinder with one end seamed in place which is then closed with a second end, or two piece consisting of a body formed from a single piece of metal closed with an end (see Fig. 11.1). Aluminium cans are always two piece whereas steel cans may be either three piece or two piece . The end or ends are seamed onto the can body which involves the forming of a double seam of folded metal (see Fig. 11.2). A hermetic seal (a key element of metal food and beverage packaging) is ensured by the incorporation of a 

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Metal packaging and chemical migration into food 251... 

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