SuperLite I-XL Alert

When it comes to fire protection and life safety in buildings, it's critical to specify and install proper products. The makers of a glass called SuperLite I-XL promote the material for fire-rated applications of 45 minutes and more. However, this claim can be challenged due to the number of "limitations" attached to the product listing.

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SuperLite I-XL Alert

The documents linked below are intended to provide you with essential information on this critical topic. Before considering the use of SuperLite I-XL or any other products that don't meet testing standards, please review this material thoroughly. For further questions, please call 1-888-397-FIRE, or contact

Product Advisory Bulletin
SuperLite I-XL Listing
California State Fire Marshal Data Sheet

The Issue

The fire-rated glass product, SuperLite I-XL, is advertised as carrying 45 and 60 minute fire ratings. However, closer inspection reveals that the listing has significant limitations:

  1. SuperLite I-XL does not pass the mandatory hose stream test – a requirement for any rating in the U.S. over 20 minutes. There are dozens of alternative choices with ratings of 45 minutes or more, from multiple manufacturers. SuperLite I-XL is the only product that does NOT comply with the standards – yet still claims to have a 45-60 minute fire-rating.
  2. SuperLite I-XL is directional. In other words, it provides fire protection from one side only. That means someone is responsible for determining where the fire will start; a nearly impossible task. Who makes and is willing to accept the liability of that decision? The architect? General Contractor? Glazing Contractor? Building Official? Choose incorrectly and you have little if any fire protection at all.
  3. SuperLite I-XL does not meet fire wall test standards. Verbiage in the manufacturer's promotional materials might lead one to believe the product meets the very stringent test requirements of ASTM E-119 and UL 263. The product does not meet these test standards and should not be used where barrier to heat transfer wall products are required.

Q & A

If SuperLite I-XL doesn't pass the required testing, how can it have a listing?

Originally, Warnock Hersey International issued a "conditional" listing for the product to be used in one specific government application. However, the manufacturer has marketed SuperLite I-XL for general use. Warnock Hersey is the only independent lab that has given this type of listing for a non-compliant fire-rated glass product. The most well-respected laboratory for fire testing in North America, Underwriters Laboratories (UL), will not provide a 45 or 60-minute listing for products that do not pass both fire and hose stream test requirements.

Is the hose stream test all that important? It seems like fire resistance is the main issue.

The hose stream test is critical. Building codes require that fire-rated glass materials comply with the test standards and guidelines developed by the National Fire Protection Association (NFPA). The 2007 edition of the NFPA "Fire Test of Window Assemblies" gives the following explanation regarding the hose stream's importance and validity:

B.11.4 "The hose stream test provides a method for evaluating the integrity of constructions and assemblies and for eliminating inadequate materials or constructions. The cooling, impact, and erosion effects of the hose stream provide tests of the integrity of the specimen being evaluated."

Despite repeated attempts by the manufacturer of SuperLite I-XL to have the hose stream test eliminated, code officials and fire protection experts have continued to uphold the validity and value of the hose stream test.

Why would Warnock Hersey issue this listing?

We've been asking the same thing, with no clear answer. To draw an analogy, no one would expect to get a driver's license if they passed the written but not the driving portion of the test. Both components are required. No one has a license with a disclaimer.

Issuing a fire rating that arbitrarily leaves out a mandatory portion of the testing sets a disturbing precedent. We believe it undermines the integrity of the entire testing and listing process. We urge you to contact Warnock Hersey directly with any concerns you may have. Email us with your questions and concerns at

What is a "directional" product?

SuperLite I-XL has a coating on one side of the glass that reflects heat away from that surface of the glass. Since this monolithic glass is not symmetrical, it only offers fire protection from one side. This raises two key issues:

  1. Code Compliance – The International Building Code section 715.5.2 requires that nonsymmetrical glazing be tested with both faces exposed to the furnace, and the assigned fire protection rating shall be the shortest duration obtained from the two tests conducted in compliance with NFPA 257. SuperLite I-XL does not comply with this building code requirement.
  2. Installation – As a directional product, SuperLite I-XL requires that the identified face MUST be installed facing the direction of the expected fire attack. Unless you are 100% certain you can predict where a fire will originate, you risk offering no protection where it will be needed.

Isn't it good that SuperLite I-XL offers some heat protection?

It sounds good, but the simple truth is that the codes are very clear: Where a barrier to heat is needed, the product has to meet the standards of a barrier wall complying with test standards ASTM E-119 and UL 263. Ordinary window glass can't live up to the requirements – no matter how much heat it reduces. There ARE specialty glazing materials that do function as a wall and block heat transfer from multiple manufacturers.

A "degree" of heat reduction isn't helpful in meeting the required building code and test standards.

Ask your TGP sales rep about product solutions that meet U.S. building code requirements.

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