What type of unshielded twisted-pair (UTP) cable is designed to minimize fire risk and reduce toxic fumes?

Plenum-rated cable, known as CMP (Communications Multipurpose Cable, Plenum), is specifically designed for installation in spaces that facilitate air circulation for heating and air conditioning systems. These areas include ceiling spaces above drop ceilings or under raised floors where fire safety is a primary concern. CMP cables are constructed with materials that have a low flame spread and produce minimal toxic fumes when burned, which is crucial in fire-prone environments.

In contrast, riser-rated cables (CMR) are designed for vertical spaces between floors and provide a different level of fire resistance compared to plenum cables. While they are still fire-resistant, they do not meet the same stringent safety requirements as plenum-rated cables. Standard UTP cables, like Cat 5, do not have special fire safety certifications and are not suitable for use in plenum spaces. Shielded twisted-pair (STP) cables, despite their shielding, do not inherently possess the fire-resistant qualities attributed to CMP cables.

Thus, CMP is the correct choice for minimizing fire risk and reducing toxic fumes in sensitive environments.