It has been pretty standard practice when installing new communications cabling to leave the old cabling in place because it is costly and time-consuming to remove. Abandoned cable, however, creates a significant fire hazard. In fact, the National Electrical Code now requires the removal of accessible portions. The problem is not the copper wire but the plastic insulation and jacket. These can create the same fuel load as gasoline. When heated, the plastic can release gasses, which can stop respiration or blind. Another issue is the lead content in the jacket, which can be ten percent by weight. When the PVC in the jacket breaks down, it releases lead dust, which then blows around the facility. Once the abandoned cable has been removed, remember to minimize the amount which ends up in a landfill or incinerated by recycling as much of the plastic and metal it contains as possible.
