Abstract: A highly flame retardant, impact modified polyolefin alloy is described, the composition of which includes: at least one polyolefin; at least one halogenated organic flame retardant; at least one semi-crystalline ethylene copolymer impact modifier, the copolymer optionally being functionalized, at least one oxygen-containing metal compound wherein the metal is selected from the group consisting of Group III, IV, V, and VI of the Periodic Table; and at least one fluorocarbon, at least a portion of which is fibrillated or fibrillatable. Optionally, the alloy will contain at least one of a functionalized silicone polymer, a hydrated metal silicate, a hydrated metal borate, a primary antioxidant, and a secondary antioxidant. Such thermoplastic polymer blends/alloys can be produced by combining all ingredients in a melt and applying shear to the melt through means of a high shear internal/continuous mixer or an extruder.