Migration studies of photoinitiators with different volatilities from plastic packaging to milk powder.

The migration of photoinitiators (PIs) from plastic packaging materials, leading to food contamination, has garnered increasing attention. However, discrepancies among previous studies regarding PI migration have been reported, primarily due to the neglect of the impact of PI volatilization on migration. In this study, the migration of PIs with different volatilities from plastic packaging into milk powder was investigated. The migration behavior of more volatile PIs (4-MBP, PI-184, and EDB) and less volatile PIs (EHA and PI-907), were investigated under different conditions, such as migration time, temperature, concentration, humidity, as well as the thickness and type of the migration medium. Concurrently, a model founded on Fick's second law was utilized to simulate the migration behavior of less volatile PIs, successfully deriving diffusion coefficients and partition coefficients with a high degree of fitting accuracy. Furthermore, a Weibull model was applied to forecast the migration behavior of more volatile PIs, providing insights that may inform the selection of PIs for food packaging printing applications. This study provides a mechanistic understanding of how photoinitiator volatility influences migration into milk powder and establishes predictive models to support food packaging safety assessment.