NEC ? requires electrical penetrations to be firestopped.

• A. 300.21
• B. 310.15
• C. 200.1
• D. 400.8

Answer: (A)

Firestopping around electrical penetrations is about preserving the fire-resistance of walls and floors. The NEC includes a specific requirement that penetrations through fire-rated assemblies, where conductors or cables pass through, must be firestopped with an approved system. This rule is found in 300.21. It ensures that openings don’t become pathways for flames, smoke, or hot gases, helping to maintain the integrity of the fire barrier in a building. The other sections pull in different topics—one addresses conductor ampacity and temperature corrections, another covers general scope or applicability, and another deals with flexible cords—none of which dictate firestopping of penetrations. So the NEC provision that explicitly requires firestopping around electrical penetrations is 300.21.