Toxic materials cable?

All fireproofing and firestopping systems are passive fire protection measures subject to stringent bounding. The cable trays themselves are only of concern if they are made of plastic. Typically, what is of most concern, is the items, which are placed upon the trays. In some cases, the primary concern is to mitigate the fuel load that the cable jacketing represents. As cable jackets burn, even fire-retardant ones, a large amount of toxic and re-ignitable smoke and chlorine are released. This bonds with airborne moisture, thus yielding hydrochloric acid. Mitigation methods include the use of fire retardants, as well as concealment, panelling and fire-resistant wraps. The other concern is circuit integrity. Particularly, though not exclusively in nuclear reactors, it is necessary to maintain the operability of cables during a fire, so that critical equipment, such as reactor cores, safety valves, etc. can be shut down, to prevent a catastrophe. While the first example considers the effect of the burning cables upon their environment, the latter considers the effect of burning surroundings on the cables themselves. It is possible to use mineral insulated cables, which are inherently fire-resistant. This is not an inexpensive proposition, but it is certainly proven technology. Otherwise, one may use purpose- designed boxes or wraps to keep fire and heat away from the cables.