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New Marks for Fire Rated Glazing Assemblies

SuperLite I label in fire rated glass

You’ll inevitably come across the International Building Code (IBC) for fire rated assembly and fire rated glazing projects. The IBC table is a valuable document for contractors and architects, as it identifies the requirements for staying compliant with building codes, such as fire safety standards.

IBC’s Chapter 7 is dedicated to fire and smoke protection, serving as your guide to the materials, systems, and assemblies recommended to protect structures from fire and smoke.

Every state must comply with the building codes, which the International Code Council updates every three years to reflect changes in building designs along with prescriptive and performance-related guidelines on public health and safety.

IBC 2021—the latest version in use in the U.S. and other countries that adopt the international building code—features, among others, updates in the marking and rating systems. These updates are for the following categories: fire rated glazing assemblies, opening fire protection assemblies, and fire window assembly fire protection.


What’s new: Letters replace test standards on labels

Like the 2018 edition, the IBC 2021 edition uses letters to indicate the performance standard of a particular fire rated glazing product, such as the ones provided by SAFTI FIRST. Thus, instead of abbreviations of a specific fire test standard, what you will see on fire-rated product labels are the letters W, FC, OH, D, H, and T.

However, the table below shows the addition of the FC marking, which is a new entry under fire rated glazing assemblies.

2021 IBC Table 716.1(1)

Here’s what the letter markings mean to fire test standards.

  • W means the wall assembly is fire resistive and compliant with ASTM E119 or UL 263.
  • FC means the floor or ceiling assembly is fire resistive and passes ASTM E119 or UL 263.
  • OH means the fire window assembly is fire protective and complies with NFPA 257 or UL 9, meeting the test standard requirements for both fire endurance and hose stream.
  • D means the fire door assembly is compliant with these test standards: NFPA 252, UL 10B, and UL 10C.
  • H means the fire door assembly has been tested for the hose stream procedure.
  • T means the temperature rise door assembly intended for exit enclosures and passageways meets the temperature rise limit of 450˚F for 30 minutes.

The XXX markings in the table above represent the two- or three-digit numbers on labels for fire rated glazing assemblies, indicating their fire protection or fire resistance time duration capabilities in minutes.


Multiple letters for glazing that passes more than one test standard

Fire rated glazing products with a combination of various markings on their labels tell you they have passed not just one but multiple fire test standards. Here are a couple of examples:

  • W, D-H-T: These markings indicate passing both the wall fire and fire door assembly tests. With this information, you’ll know that the glazing is fire-resistant and can exceed the 100 sq. in. door vision area limitation imposed on fire protective glazing in 60- and 90-minute temperature rise doors.
  • D-H: When you see these markings, you’ll know that the glazing is fire-protective and can prevent fire and smoke from spreading. Both wired glass and ceramics, being types of fire-protective glazings, typically carry D-H markings. Although wire and ceramics have a fire endurance rating of up to 90 and 180 minutes respectively, they are limited to 100 sq. in. in 60, 90 and 180 minute temperature rise doors because they do not have the W marking, which is reserved for fire resistive glazing products that meet ASTM E119 or UL 263.


Letters Sync with Chapter 7 tables

The primary purpose of using markings in IBC is to ascertain if fire rated glazing applications are properly implemented. In the 2021 IBC, Table 716.1 is subdivided into three categories to cover both fire protection and fire resistance glazing.

  • 716.1(1) Marking Fire Rated Glazing Assemblies

    This table indicates the fire test standard, marking, and definition of marking for the following assemblies: wall, floor, ceiling, fire window, and fire door.

  • 716.1(2) Opening Fire Protection Assemblies, Ratings, and Markings

    This table specifies the vision panel size limits and sidelite and transom rating requirements. It also helps you distinguish between fire protective (or fire-protection-rated) and fire resistive (or fire-resistance-rated) products by identifying size limits for fire protective glazing, indicating when fire resistance rating products must be used in larger applications, and specifying applications where the code only allows glazing that meets the fire wall test standard.

  • 716.1(3) Fire Window Assembly Fire Protection Ratings

    Here, you can identify where fire-protective products are permitted or otherwise. The table also shows where you must use fire-resistive glazing, such as in 120-minute interior walls.


Examples of labels on SAFTI FIRST’s glass products

  1. SuperLite I

    SuperLite I label

    The D-20 marking on the SuperLite I means its glazing can be used in 20-minute doors. Note that in the IBC, glazing used in 20 minute door vision panels are exempt from the hose stream test. NFPA 252/257 and UL 9/10B/10C indicates the product has passed the fire door and fire window test standards, respectively. SuperLite I meets the CPSC Cat. II safety requirement.

  2. SuperClear 45-HS-LI

    SuperClear 45-HS-LI label

    SuperClear 45-HS-LI meets the 45-minute fire window assembly criteria, including the hose stream test (UL 9) and 45-minute fire door assembly criteria (UL 10B or UL 10C). It also meets the CPSC Cat. II safety requirement.

  3. SuperLite II-XL 60

    SuperLite II-XL 60 label

    Designed to be used in areas where fire protective glazing is not permitted or increase the vision area in a 60-minute temperature rise door, SuperLite II-XL 60 meets the following criteria: wall assembly test standard (ASTM E119), and fire wall test standard (UL 263) and temperature rise limit (T) of 450°F for 30 minutes. It also meets the CPSC Cat. II safety requirement.


Final Word

With the release of the IBC 2021 edition, there’s no more confusion as to whether you should use fire-protective or fire-resistive glazing—provided you familiarize yourself with the new markings for fire rated glazing assemblies.

Besides helping you understand what the codes mean, SAFTI FIRST can provide you with USA-made fire-rated solutions that protect your buildings against fires without compromising aesthetics.

Questions? Contact us today about our products →

Do you have a current or upcoming project that needs fire rated glass and framing? Contact us today!