Penetrations shall be sealed by devices listed for such use, provided their presence does not detract from the hood's or duct's ______.

• A. Weight
• B. Appearance
• C. Structural Integrity
• D. Thermal Conductivity

Answer: (C)

Sealing penetrations must not weaken the hood or duct. The requirement is that any device used to seal openings—when properly listed for that purpose—keeps the hood’s or duct’s structural integrity intact. If a sealing device compromised the framing, support, or overall strength of the system, it could fail under heat or airflow conditions, defeating the protection the system is meant to provide. So the focus is on preserving structural integrity.

Weight, appearance, and thermal conductivity aren’t the controlling safety concerns in this context. A listed seal should preserve strength and fire resistance, not just look or weigh less or more, nor primarily affect insulation.