Code Q&A
All About Safety Glazing, from the NGA Advocacy and Technical Team
During the “All About Safety Glazing” webinar at GlassBuild Connect in September, the National Glass Association’s Advocacy and Technical team answered common questions about safety glazing, including test standards, labeling, certification and applications. Below are highlights from the session.
Visit glass.org for additional safety glazing resources.
Julie Schimmelpenningh
Eastman Chemical Co., NGA Laminating Technical Liaison
Q: Is all laminated glass safety glazing?
A: No, because glass interlayers are available in different formulations and thicknesses, and not all of them will make two lites of glass laminated together pass safety glazing tests. Similar to tempered glass, laminated glass is only considered safety glazing once it passes 16 CFR 1201 or ANSI Z97.1 [Standard Safety Glazing Materials Used in Buildings - Safety Performance Specifications and Methods of Test].
Q: ANSI Z97.1 has several tests, including impact, weathering and center punch. Are all of these required for safety glazing, or is only the impact portion of the test standard required for safety glazing?
A: ANSI Z97.1 is both a standard and a test method, and all portions are required. However, not all portions apply to each type of safety glazing. For example, center punch is required only for tempered glass. The weathering portion applies to laminated, filmed and organic coated glass and plastics. So yes, all portions of ANSI Z97.1 are required to the extent that they apply to the type of glazing being evaluated.
Q: What part of safety glazing requirements fall under the glazing contractor’s responsibility?
A: From a glazing contractor’s perspective, it starts with ensuring the specification is correct for the requirements of the project, then having the fabricators and suppliers ensure they have the proper labeling, markings and documentation that the safety glazing testing and certification are current. The actual testing of the product falls onto the glass supplier, not the glazing contractor.
Q: Are there additional testing requirements for glazing used in behavioral health settings or when ballistics glazing is used as safety glazing?
A: The building code requires safety glazing in life safety areas. When there are additional performance requirements for specific applications beyond life safety, they are specified for the project by the building owner or designer. There are many test standards available to qualify the glass for behavioral health and ballistic applications, but they are not necessarily part of the building code requirements. If the glazing construction has not been certified before, the glass or polycarbonate may be qualified alone, and the interlayer might pass as a component. Typically bullet-resistant laminates tend to be thicker and meet the impact requirement easily, but you must make sure all the other test requirements are met for the components in the laminate.
Q: What are the weathering requirements for laminated glazing products?
A: The weathering requirements in ANSI Z97.1 have been updated to clarify what is required: either one year of natural exposure or 3,000 hours of accelerated exposure in a xenon-arc apparatus. To pass the weathering test, there are limits on allowable change in yellowness index, visible light transmission, haze increase and overall change in color. Weathering testing does not need to be done on every test submission. Rather, the component suppliers of the interlayers and films submit their products for weathering data and provide this data to the glass fabricators.
Thom Zaremba
Roetzel & Andress, NGA and GICC Fire/Structural and Safety Glass Consultant
Q: Is all tempered glass safety glazing?
A: No, all tempered glass is not necessarily safety glazing. To qualify as safety glazing, the glass must be tested and meet the acceptance criteria of Consumer Product Safety Commission 16 CFR Part 1201 Safety Standard for Architectural Glazing Materials or ANSI Z97.1 Standard Safety Glazing Materials Used in Buildings - Safety Performance Specifications and Methods of Test.
Q: Are the requirements of 16 CFR 1201 the same as those in the building code?
A: There is one very important difference to be aware of. In 16 CFR 1201 there is a complete exemption for wired glass complying with the safety standard if it’s used in a fire-rated application. The building codes demand a higher standard. While 16 CFR 1201 is a federal standard and preempts any contradictory standard that has lesser requirements, it does not preempt higher requirements. Therefore, if wired glass is used in a hazardous location, whether in a fire-rated application or not, it must comply with ANSI Z97.1.
Urmilla Sowell
NGA Technical and Advocacy director
Q: When is tempered laminated glass required rather than annealed laminated?
A: The requirement to use heat-strengthened or fully tempered laminated glass versus annealed laminated is based on the design loads for the application. For balustrades and guards, the building code requires heat-strengthened or fully tempered laminated. For safety glazing for patio doors opening onto a patio, annealed laminated glass meeting safety glazing requirements can be used. The only restriction would be when wind loads are higher; for example, in high-rise buildings.
Q: What types of organic coated glazing pass as safety glazing?
A: The Safety Glazing Certification Council, SGCC, maintains a certification program where manufacturers of safety glazing products voluntarily submit their products for testing to an SGCC-approved independent testing laboratory. Check their website to see what is listed and certified. Organic coated products could range from a surface applied film to a tape on the back of mirrored glass. There are requirements in ANSI Z97.1 for weathering, durability and adhesion for those materials.
