Hermetically sealed packages may be made utilizing masterbatches made according to the present invention.A sealant layer preferably comprises a heat sealable polymeric material such as polyolefins including polypropylene homopolymers, polypropylene copolymers, very low density polyethylene (VLDPE), ultra low density polyethylene (ULDPE), linear low density polyethylene (LLDPE) or homogeneous polyo