Time dependent styrene migration

One can assume that styrene migration out of PS into food is slowed down or braked by the diffusion of styrene in the plastic material (P). Eq. (14-4) the simplified expression for the estimating the concentration, cF.i (mg kg-1),of the styrene in the food (F) at time t can be used  

Dp is the estimated diffusion coefficient of styrene in the plastic material (cm2 s ) using Eq. (14-5), t is the expected shelf life (s). 

The statement cFt cF t in Eq. (14-4) indicates the tendency of the estimation to overpredict the actual migration due to the estimation of DP and some simplifications made in deriving Eq. (14-4) (see Chapters 7 and 15). 

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