Which statement best describes testing requirements for plenum cables under NEC standards?

• A. Flammability and smoke density are tested per UL and NFPA standards.
• B. Only voltage rating is tested.
• C. No testing is required.
• D. Water resistance is the main test.

Answer: (A)

Cables installed in air-handling plenums must be rated for fire safety, not just function. The NEC requires plenum-rated cables to be tested for how they burn and what kind of smoke they produce, so they won’t spread a fire or create dangerous smoke in these ventilation spaces. This testing is carried out under UL and NFPA standards, focusing on flammability and smoke density. That’s why this statement is correct. Relying only on voltage rating misses the essential safety requirement for plenums, and claims about no testing or about water resistance do not address the fire/smoke criteria that NEC specifies.