Abstract: The insulating formulation is a mixture of vulcanizable halogen free polyolefins with low smoke emission and fire resistance characteristics, for application in compounds to insulate and cover cables and electric conductors. The polyolefins are formulated with a hydrated inorganic charge, an alkoxysilane, a curing agent, an additive such as a process assistance agent and a combination of two antioxidants, a hindered phenol and a zinc-mercapto toluimidazole salt. The stabilized formulations with the antioxidant combination of phenol with steric hindrance and zinc 2 mercapto toluimidazole salt offer a good thermostability at 3000 hours at a temperature of 125.degree. C. and at 240 hours at a temperature of 165.degree. C. and does not stain or decolorate the copper surface when the composition is steam vulcanized.

Abstract: A coextruded triple layer electric conductor for cable insulation having low humidity absorption, low emission of toxic gases, low smoke emission and high flame retardance comprising a first layer comprising polyvinyl chloride as a base over an electric conductor core, a second layer over first layer, comprising high density polyelthylene optionally modified with an ethylene copolymer, and a third layer over said second layer comprising polyvinyl chloride as a base.