Newer materials, principally low-smoke, zero-halogen (LSZH) plastics, emit no dangerous gases or smokes when burned. In fact, they may contain miniscule trace amounts of halogens, well under 1%, but they essentially are halogen free. The drawback to LSZH, safe as it is, is that it cannot be conveniently recycled and reused. Like PVC, it will sit in a landfill for centuries. On the other hand, EcoWire’s® patented Noryl® insulation contains no halogens and can be fully recycled.