In a previous post, I talked about where safety glazing is required, but what IS safety glazing?  More from the 2009 IBC:

2406.1.1 Impact test. Except as provided in Sections 2406.1.2 through 2406.1.4, all glazing shall pass the impact test requirements of Section 2406.2.

Note that “all glazing” means “all glazing in hazardous locations.”  This includes all glass in swinging and sliding doors as well as many other locations (refer to the previous post for details).

2406.2 Impact test. Where required by other sections of this code, glazing shall be tested in accordance with CPSC 16 CFR 1201. Glazing shall comply with the test criteria for Category I or II as indicated in Table 2406.2 (1).

Exception: Glazing not in doors or enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers shall be permitted to be tested in accordance with ANSI Z97.1. Glazing shall comply with the test criteria for Class A or B as indicated in Table 2406.2 (2).

(click to enlarge tables)
IBC Tables

The tables referenced in this section identify whether safety glazing must be Category I or II (CPSC 16 CFR 1201) or Category A or B (ANSI Z97.1).  This depends on where the glass is used and the exposed surface area.  But what’s the difference?  The Glass Association of North America (GANA) has published a detailed comparison of the two standards, and here is some information from that document:


The principal differences between the CPSC’s 16 CFR 1201 standard and the ANSI Z97.1-2004 standard relate to their scope and function. The CPSC standard is not only a test method and a procedure for determining the safety  performance of architectural glazing, but also a federal standard that mandates where and when safety glazing materials must be used in architectural applications and preempts any non-identical state or local standard. In contrast, ANSI Z97.1 is only a voluntary safety performance specification and test method. It does not attempt to declare when and where safety glazing materials must be used, leaving those determinations up to the building codes and to glass and fenestration specifiers.


The CPSC requires the installation of safety glazing materials meeting 16 CFR 1201 only in storm doors, combination  doors, entrance-exit doors, sliding patio doors, closet doors, and shower and tub doors and enclosures. Other than  that, meeting CPSC’s requirements is necessary only when and if a building code authority or other jurisdiction  adopting safety glazing laws specifically mandates that safety glazing comply with the CPSC standard, 16 CFR 1201 —  and most building codes do.

ANSI Z97.1, as a voluntary standard, applies only when, where, and if it is adopted by a building code authority or is specified in the approved plans and specifications of the architect, building contractor, or other glass specifier. 

The test requirements for both of these standards are very similar – the weight of the bag, the height from which it is dropped, the specifications of the test sample.  And to simplify things, most of the glass suppliers I checked show both listings on their impact-resistant glass (examples:  Anemostat, TGP).  Based on the test standards, CPSC 16 CFR 1201 Category II, and ANSI Z97.1 Category A both require a 100-pound bag dropped from a height of 48 inches (the most difficult category to pass), so if your glass meets this requirement, you’ve got it covered.  For locations that don’t require Category II / Category A, other types of glass may be more cost-effective.

To re-cap what we’ve learned so far:

1) Traditional wired glass does not meet the current code requirements for impact-resistance.  It is not safety glass, and does not provide more security.  It is extremely dangerous and is responsible for more than 2,000 injuries each year IN SCHOOLS.

2) The 2009 International Building Code (IBC) requires glass used in doors, sidelites, and other “hazardous locations” to be impact-resistant.  The level of impact-resistance required depends on where the glass is used and the size of the exposed glass.

3) The standards that apply to impact-resistance of safety glazing are CPSC 16 CFR 1201 and ANSI Z97.1.  Each standard has categories of impact-resistance, with CPSC 16 CFR 1201 Category II and ANSI Z97.1 Category A providing the highest degree of protection.

What else we’re going to learn:

4) How to decipher the identification marks on the glass to determine whether it is acceptable for use in fire doors and hazardous locations.  There IS wired glass that is impact-resistant (although the vast majority of the existing wired glass is NOT), so we need to know how to tell the difference.

5) What the previous editions of the IBC required, and how the code change was accomplished.

6) What does NFPA 101 – The Life Safety Code require in regards to glass.

7) How to address the existing traditional wired glass in schools and other facilities, to prevent injuries.

Anything else you’re wondering about?

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