The present disclosure is directed to compositions and film structures suitable for heat seal production. The heat sealable flexible film structure includes: a layer (A) comprising a blend comprising from 35 to 80 percent by weight of the layer (A) of a propylene based plastomer or elastomer (“PBPE”) and from 20 to 65 percent by weight of the layer (A) of a low density polyethylene having a density in the range of from 0.915 g/cm3 to 0.935 g/cm3, wherein the blend has a melt index (as determined according to ASTM D 1238 (at 190° C./2.16 Kg); a layer (B), adjacent to layer (A), comprising a polyolefin-based polymer, wherein the polymer or polymer blend which makes up layer (B) flows more easily than the blend of layer (A) under conditions intended for making a hard seal with the film structure; and an outermost layer (C) comprising a material having a melting point greater than 140° C.; wherein the ratio of the thickness of layer (B) to the thickness of layer (A) is 3:1 or greater. The heat sealable flexible film structure is used to make a flexible container having one or more heat seals. The heat seal can be a frangible heat seal, a hard heat seal, or a combination of frangible heat seals and hard heat seals depending on the sealing conditions.