UL 10C Fire Door viewers

Explanation Based on UL Standards

Your door viewer is UL Listed, meaning it has been independently tested and certified by Underwriters Laboratories (UL). This listing confirms that the product complies with UL’s strict safety, performance, and fire-protection requirements. For fire-rated door assemblies, UL evaluates not only the materials but also how the product behaves when exposed to real fire conditions.

UL 10C Fire-Rated Performance (20 Minutes / 1.5 Hours)

Your door viewer is certified under UL 10C: Standard for Positive Pressure Fire Tests of Door Assemblies. This is the most widely recognized fire test standard in North America for modern fire-rated doors.

Under UL 10C, the door viewer must withstand:

1. Positive Pressure Fire Exposure

UL 10C simulates real fire conditions where pressure forces hot gases and flames toward openings. A door viewer must resist:

*Heat up to 1,700°F (927°C) depending on test duration

*Smoke and flame penetration

*Deformation or material failure under pressure

This ensures the viewer does not compromise the fire door’s integrity.

2. Time-Based Ratings

Your product has passed:

*1/3 hours fire rating: Typically required for residential or light commercial fire doors

*1.5 hours fire rating: Required for high-risk or fully fire-rated commercial steel doors, stairwell doors, hotel doors, and public buildings

Passing these tests means the viewer remains intact, the lens does not fail or melt, and the assembly continues to block flames and smoke during the entire fire exposure period.

Why UL Certification Matters

*Ensures the door viewer does not become a weak point in a fire-rated door

*Meets building code requirements (IBC, NFPA 252, NFPA 80)

*Provides safety assurance for commercial and residential fire-protection systems

*Required for many international construction and project approvals

Door viewers are commonly employed on hotel, motel, and apartment entrance doors with the purpose of allowing individuals to visually assess the person on the opposite side of the door without necessitating the act of opening the door. Conference and meeting rooms often have door viewers, which enable service personnel to peek inside the room without disrupting the ongoing meeting. 

Certain models of door viewers are listed and have received approval for usage on openings that are fire-rated. 

Make sure to include the thickness of the door when you order door viewers, so that they can be the right length to fit the door they will be installed on. 

Click here for additional details on door viewer.

Now contact us.

Contact information for David Jian

Contact number: 0086-139 2903 7292

Email address: sales@danddhardware.com