{"id":9969,"date":"2015-07-02T09:55:53","date_gmt":"2015-07-02T13:55:53","guid":{"rendered":"http:\/\/www.constructionspecifier.com\/?p=9969"},"modified":"2016-12-20T15:58:46","modified_gmt":"2016-12-20T20:58:46","slug":"the-hazards-of-traditional-wired-glass","status":"publish","type":"post","link":"https:\/\/www.constructionspecifier.com\/the-hazards-of-traditional-wired-glass\/","title":{"rendered":"The hazards of traditional wired glass"},"content":{"rendered":"
\"Stairwell\"<\/a>
Photos courtesy Allegion<\/span><\/figcaption><\/figure>\n

by Lori Greene, CSI, AHC\/CDC, CCPR, FDAI
\n<\/strong>For decades, traditional wired glass\u2014with its crisscrossed wires creating diamonds or squares\u2014was installed in buildings around the world. Thanks to its ability to remain intact even when broken, it was the first and, for years, only form of glazing<\/a> available for fire door assemblies in schools, hospitals, and other buildings.<\/p>\n

Over time, this glazing became known as \u2018safety glass\u2019\u2014a name that would persist long after it was found to cause severe and often life-threatening injuries when subjected to human impact. Its reputation for safety has been reinforced by its appearance and the common misconception the wire mesh makes the glass stronger. In reality, the exact opposite is true.<\/p>\n

The wire mesh actually weakens the glass to such a degree \u2028it is only half as strong as ordinary annealed glass. To make matters worse, when an adult or child\u2019s arm, leg, or other body part projects through the glass due to impact, the initial injury is made significantly worse when the person instinctively pulls his or her injured limb back through the jagged shards of glass held in place by the wires. Severed arteries, nerves, and tendons are common injuries from impact with traditional wired glass.<\/p>\n

Nowhere has this type of glass caused more injuries than in schools. In 2002, an epidemiologic study<\/a> of Consumer Product Safety Commission (CPSC) injury data was conducted by Philip L. Graitcer of Emory University. Of the 2554 glass door injuries that occurred in U.S. schools in a one-year period, Graitcer stated he would \u201cconservatively estimate that 90 percent of the 2500 glass door injuries seen each year\u2028in the CPSC system involved wired glass.\u201d This works out to 2250 wired glass injuries in a single year. Taking into account the fact schools are only in session 180 days each year, it works out to a little more than 12 potentially debilitating and life-altering injuries\u2014some resulting in death due to blood loss\u2014every single school day.<\/p>\n

Safety glass standards
\n<\/strong>As early as the 1960s, glass manufacturers recognized the need for industry standards even though building codes remained silent on the subject of safety glazing. A task group was formed and their studies found an average of 320,000 injuries per year from people impacting glass in doors and windows (all building types, including residential). In 1966, the standard developed by this task group was accepted as American National Standards Institute (ANSI) Z97.1, American National Standard for Safety Glazing Materials Used in Buildings<\/em>.<\/p>\n

When the Consumer Product Safety Commission was created in 1972, one of its first initiatives was to address the standards for safety glazing. CPSC 16 Code of Federal Regulations<\/em> (CFR<\/em>) Part 1201, Safety Standard for Architectural Glazing Materials<\/em>, was developed as a two-tiered standard that went beyond the requirements of ANSI Z97.1, and became law in 1977.<\/p>\n

\"Storefront\"<\/a>
This large expanse of traditional wired glass could be lethal to someone walking or riding on the sidewalk in front of this retail store. As the exemption previously included in the codes applied only to wired glass in fire door assemblies, this glass installed in non-fire-rated storefront framing is not code-compliant and carries enormous burden of liability. <\/span><\/figcaption><\/figure>\n

ANSI Z97.1 has since been revised to include three levels of impact-resistance:<\/p>\n