Testing polymeric coatings on metal and paper substrates

The predicted migration test requirements for food and beverage cans with internal lacquer coatings and plastics paperboard composites against future EC legislation, are described. In a project currently in hand at Pira International on behalf of the UK Ministry of Agriculture, Fisheries and Food, some of the problems which arise when migration testing food and beverage cans with the food simulant 3% (w/v) acetic acid solution are being investigated. The 3% (w/v) acetic acid simulant has a tendency to penetrate the lacquer coating resulting in corrosion of the metal substrate. Experiments in hand and planned on this problem, with some of the initial results, are presented. There are also problems with overall migration testing of food packaging consisting of plastics paperboard composites with the fatty food simulant (olive oil). With one particular problem there is at present no obvious answer.