Migration of DINP and DOP plasticisers from PVC sheets into food

Over the last few decades, the use of plastics as packaging materials has increased due to their properties and processibility. On the other hand, as a result of contact of packed food with plastics, traces of plastic components may migrate into the food medium contaminating it and affecting consumers' health. This work concerns the study of migration of DINP and DOP plasticisers from PVC sheets into foodstuffs. PVC sheets using either type of plasticisers with different concentrations were prepared and then put in contact with different food simulants. Gravimetric analysis was used to determine the loss in plasticised PVC sheets upon immersion in food simulants. Changes in mechanical properties of tested sheets were observed. IR was used in the detection of plastic components in food simulants. A comparison was held between the migration of DINP and DOP plasticisers into food simulants. Experiments were performed to study the effect of temperature on percent loss in weight of PVC resin alone and the resin with thermal stabilizer. Tribasic lead stearate was used as thermal stabilizer. Experiments were also carried out to test the effect of heat on unplasticised PVC at different temperatures and heating duration and on PVC sheets plasticised with DOP and DINP. Samples were weighed before being exposed to heating in the oven (wo). They were then heated in the oven at the required temperature and were weighed every 5 hours (wt). Percent change in weight was obtained by substituting in equation (1): % loss in weight = woÿwt