A jacket for an electrical conductor, which jacket includes from about 40% to about 50% by weight of a polyvinyl chloride resin and from about 0.1% to about 0.5% by weight of an unsaturated primary amide derived from erucic acid. The jacket may also include from about 20% to about 35% by weight of a filler; from about 20% to about 30% by weight of a phthalate-based plasticizer; and from about 0.5% to about 5% by weight of a lead-free heat-stabilizing system. Methods for manufacturing a lead-free NM jacket are also provided.