The effects of microwave heating on the migration of contaminants from plastic into food simulants

Plastic food packaging contains potentially toxic chemicals that are capable of diffusing to the plastic surface through the process of migration, where they can contaminate food (Incarnato et al., 2000). Thus, government regulations require food packaging migration testing to ensure public safety. Standardized migration test methods use conventional ovens to determine the maximum amount of migration that will occur during heating. However, standardized migration tests may not accurately characterize the effects of microwave heating on migration. Studies by Galotto and Guarda (1999, 2004) showed that the amount of chemical migration released from polyvinyl chloride film into aqueous and fatty food simulants during microwave heating was higher than the amount released during oven heating. The objective of this study was to determine if the effects of microwave heating on migration were different from the effects of oven heating. The amount of chemicals migrating from one type of polypropylene plastic container into acetic acid and isopropanol food simulants during microwave and oven heating was measured using GC/MS analysis and compared. The results of this study showed that the effects of microwave and oven heating on migration are not comparable. The amount of chemical migration for most substances identified in acetic acid and isopropanol food simulant was significantly higher (p<0.05) in simulant exposed to microwave heated plastic compared to migration levels measured in simulant exposed to oven heated plastic. The number of migrants found in microwave heated acetic acid and isopropanol simulants (13 and 72, respectively) was greater than what was present in oven heated acetic acid and isopropanol simulants (4 and 70, respectively). The amount of identified chemical migrants in isopropanol simulant was also significantly higher (p