by Christoph — "For bev­er­age pack­ag­ing the bar­rier prop­er­ties [= very low per­me­abil­ity] of the PET to cer­tain gases, the ex­cel­lent mass to strength ra­tio and the re­cy­cla­bil­ity of the fi­nal prod­uct are very im­por­tant fea­tures in­flu­enc­ing the choice of PET over other plas­tics or more tra­di­tional pack­ag­ing ma­te­ri­als." (quoted from the essentialchemicalindustry.org web­site). Given such at­trac­tive fea­tures, it's no won­der...