What type of safety standard is involved in the use of cables listed as CMR?

Cables listed as CMR, which stands for Communications Riser, are designed to be used in vertical spaces between floors in a building, specifically in riser shafts. The classification is tied to fire resistance and flame propagation characteristics of the cables. CMR-rated cables meet specific fire safety standards that reduce the risk of flames traveling vertically between floors, which is critical in maintaining the overall safety of a building and minimizing the potential for fire spread.

These cables are engineered to restrict the propagation of flames, which is crucial when installed in vertical spaces where they could affect multiple floors. Understanding the importance of fire resistance in CMR cables helps ensure compliance with building codes and enhances safety during emergency situations. This makes fire resistance the relevant safety standard associated with CMR-rated cables, reflecting their design purpose in fire safety measures within electrical infrastructure.