A water-based barrier coating composition suitable for use as a barrier coating is disclosed which includes an aqueous polymer composition obtainable by free radical (co)polymerizing an ethylenically unsaturated monomer blend having an optionally substituted styrene, at least one C1-C4-alkyl (meth)acrylate, other ethylenically unsaturated copolymerizable monomers, degraded starch polyvinyl alcohol (PVA), a plasticizer; a composition having C16-C18 alkenyl ketene dimer, optionally as a mixture with rosin, of a gelling agent; and optionally a filler.