Accumulation model for solutes leaching from polymeric containers.

An accumulation model for predicting the equilibrium solution concentration of leachables migrating from polymeric containers has been applied to the leaching of several solutes from a blend of a styrene-butadiene-styrene block co-polymer and polypropylene. The model considers three accumulation-limiting mechanisms: total available pool, solute solubility and solute partitioning. Equations relating a solute's solvent-water partition coefficients (Po/w and Ph/w) and its polymer partitioning properties have been developed. With these equations, one can predict leachable accumulation from the container weight, solution volume and the solute's partition coefficients. The maximal accumulation of the leachable in solution will be the lowest value predicted via the three accumulation-limiting mechanisms.