Which of the following cable types should be installed to minimize toxic fumes in the event of a fire?

Fiber optic cable does not carry electrical current and has reduced fire risk, but its jacket material is not specifically rated to minimize toxic fumes in the same standardized way as plenum cable.

STP CAT6 refers to a shielding specification for reducing electromagnetic interference, not to the fire or smoke characteristics of the jacket material.

Plenum-rated cables are manufactured with jackets made from low-smoke PVC or fluoropolymer (such as FEP), which release significantly fewer toxic gases when exposed to fire compared to standard PVC jackets. Building codes such as the NEC require plenum-rated cables in plenum spaces (ceiling voids and raised floors used for HVAC air return) precisely because toxic fumes from burning cables can spread rapidly through air handling systems. No other cable category in the list is defined by fire/smoke safety characteristics.

Coaxial cable uses standard PVC or polyethylene jackets that can produce toxic fumes when burned and has no plenum-rated definition.