What type of cable does the NEC® define as fire retardant and low smoke?

The correct classification of cable that the National Electrical Code (NEC) defines as fire retardant and low smoke is the type known as plenum cable. Plenum cables are specifically designed for use in spaces with a high airflow, such as the areas above a suspended ceiling or below a raised floor, where they are more likely to be exposed to fire conditions.

Plenum-rated cables are constructed with materials that have a lower likelihood of releasing harmful smoke and toxic gases when burned. This characteristic makes them suitable for applications in environments where ensuiring the safety of occupants and minimizing smoke damage is critical, such as in large commercial buildings.

General purpose cables, in contrast, do not have the same stringent fire safety requirements as plenum cables, and thus are not suitable for use in such spaces. Riser cables can be rated for vertical spaces between floors but are not designed to have the same low smoke properties as plenum cables. Pentium is not a recognized type of cable in the context of NEC ratings and pertains to a line of microprocessors rather than cable specifications.

Choosing the appropriate type of cable according to the NEC guidelines is essential for ensuring safety and compliance in fiber optic installation.