TABLE OF CONTENTS Various workers [68-72] have carried out extensive studies of the determination of total migration of additives from plastics packaging materials into edible fats using a 14C-labelled fat simulent (HB 307). Methods based on measurement of total extract into volatile solvents such as n-heptone and diethylether were rejected at an early stage [73-86].
Unlike tests for specific migration, determination of the total migrate does not involve any direct toxicological considerations because both toxic substances and physiologically harmless packaging components are included. This test is therefore only used for checking new batches of already approved packaging materials, for which the total migration limits are known to the manufacturers. However, determining the total migrate from new packaging materials awaiting approval could give an important indication of total contamination and thus of the possible adulteration of the packed foodstuffs. Nevertheless, it has generally been considered that the determination of total migration is inadequate for a final physiological assessment of a new packaging material.
Figge and others [70, 71, 86-92] described a radiochemical method in which the total amount of material that has migrated into the fat simulant HB 307 can be estimated indirectly from the decrease in weight of the packaging material being tested. A representative sample of the packaging material is weighed before and after storage in the radioactively-labelled fat simulant (HB 307- 14C) and the amount of HB 307- 14C retained in and on the sample in spite of careful cleaning is determined...
