[Antistatic finishing of plastics from food hygiene and toxicological viewpoints]

The authors investigated experimentally the migration behaviour of formed plastics with antistatic finish. The degree of molecular coating on the surface and the rate of diffusion of the antistatics used (ethoxylated amines and alkyl sulphonate) were calculated from the results of washing-off and continuous extraction experiments. The findings are indicative of a good depot effect, i.e. the antistatic action is steadily regenerated by secondary migration. Certain agents such as polyethylene glycol enhance diffusion whereby the values for the migration in normal polystyrene are increased; but this increase is acceptable from the viewpoint of safety. In impact polystyrene, the limiting value for total migration is largely exceeded so that considerable contamination may be expected when it comes in contact with foods. From the viewpoint of food-toxicology, there are concerns about the high specific migration values of alkyl sulphonate. For this reason, its use in the food sector should be limited to such cases where direct contact with foods is excluded.