Which NEC section requires firestopping of electrical penetrations?

Which NEC section requires firestopping of electrical penetrations?

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

Answer: (A)

Firestopping is required to maintain the fire-resistance of walls and floors that are rated to resist fire. When electrical cables or conduits pass through these fire-rated assemblies, the opening must be sealed with a listed firestop material so that the rating isn’t compromised by heat, flames, or smoke.

This NEC requirement ensures that electrical penetrations don’t become pathways for rapid fire spread between compartments. The section is specifically about penetrations through fire-rated barriers and the need to install appropriate firestop products around cables and conduits, in a way that’s compatible with the penetrants and the surrounding construction.

Other topics covered in the choices—how much current a conductor can carry, how conductors are identified, and the rules for flexible cords—address different aspects of electrical systems and do not govern firestopping of penetrations.