Accumulation in Food from Packaging

General purpose PS and HIPS are used in food packaging applications. In some packaging configurations, with no direct contact of a surface with the polymer the migration of residual styrene monomer via the vapor-phase with subsequent absorption into the food is believed to be a significant mechanism of accumulation. 

Studies of the migration of styrene monomer from HIPS and likewise from PS foams via the gas phase has been determined in a sealed system. The results show that the amount of styrene migrating from the polymers is proportional to the square root of the time of exposure (34-36). 

The issues of styrene exposure to the human have been reviewed (37). Styrene has been found to be metabolized to styrene-7,8-oxide by cytochrome P450-IIE1 (38). 

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