A thermoplastic composition includes the product of melt kneading a composition including a poly(arylene ether), a polyolefin, an acid-functionalized hydrogenated block copolymer of an alkenyl aromatic compound and a conjugated diene, and a polyamine compound. The composition exhibits substantially improved chemical resistance compared to a corresponding composition lacking the polyamine compound. Methods of preparing the composition and articles prepared for the composition are also described. The composition is particularly useful for fabricating halogen-free tubes for sheathing automotive wiring harnesses.