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Wired Glass Isn?t Safety Glazing

When parents began to investigate wired glass impact strength and accepted use under building codes a year ago, they found there?s no dispute within the U.S. glazing industry about the poor impact strength and dangerous breakage characteristics of wired glass. The wires give this product the appearance of added impact strength, when in fact they actually weaken the glass, so wired glass is only half as strong as ordinary window glass and breaks more easily. What?s worse, wired glass is much more dangerous when broken, because it breaks into jagged shards, exposing razor sharp wires that catch the victim in the opening and act like a Chinese finger puzzle, causing more extensive, severe injuries. But code officials and market users don?t know the facts, so they believe the illusion.

CPSC and Building Codes Allow Its Use Under an Obsolete Exemption Building codes allow wired glass in fire-rated door and window assemblies in impact locations under an obsolete exception created over two decades ago, when there were no fire-rated glazing alternatives. When the Consumer Product Safety Commission (?CPSC?) enacted the federal safety glazing performance standard (16 CFR 1201) in 1977, wired glass was the only glazing product made that passed US fire test standards, so CPSC made an temporary exception for wired glass in fire assemblies. The exemption was supposed to terminate after a period of 2-1/2 years, giving industry time to develop a fire-rated product meeting the higher CPSC impact standards. But wired glass manufacturers challenged the termination date as arbitrary in federal court, and that issue was returned to CPSC to reopen further proceedings to supplement supporting facts?some four years later. CPSC opted to take a cheaper, easier way out, and simply deleted the expiration date, giving up on regulating wired glass in fire doors under federal law.

Building codes have conformed to CPSC regulations, and require all glazing materials in doors and other hazardous impact locations to meet CPSC 16 CFR 1201?with the exception of wired glass in fire assemblies. To meet the federal Standard, glazing must pass minimum impact tests of 150-ft. lbs. for classification as Category I safety glazing in sizes less than 9 sq. feet, and 400-ft.lbs. For classification as Category II safety glazing in sizes over 9 sq. feet. For wired glass covered by the exception, however, the building codes went back and applied the lower ANSI Z97.1 100-ft.lb. impact test standard which the CPSC threw out in 1977 as inadequate because it only protects children under five against injury from impact.

ANSI Z97.1 is a voluntary consensus safety-glazing standard developed by an industry-based committee, and reviewed every five years under the American National Standard Institute?s standard-setting procedures. The ANSI Z97.1 Review Committee has maintained the lower 100-ft.lb. impact test solely to qualify wired glass at the insistence of wired glass interests dominating the Committee, despite evidence of injuries, technology to make wired glass products meet the CPSC standards and the availability of other fire-rated alternatives. This issue is being considered this review cycle and will be put to a vote by the full Committee within the next three months.

Fire-rated Glazing Alternatives that Comply with CPSC Standards Are Available AFSG has investigated the availability of fire-rated alternatives to wired glass that meet CPSC safety glazing standards, and found that there are several clear fire-rated alternatives to wired glass that range in fire protection from 20-minutes to three hours, and most are tested to CPSC Category II impact requirements. Some have been on the market since the mid-1980s, many since the 1990s, and the number of fire-rated product options has increased significantly in recent years. These alternative fire-rated products are available through four suppliers, two based in California, two in Washington.

In obtaining information from the suppliers about the various fire-rated glazing alternatives, AFSG has learned not all products provide the same fire protection as wired glass. Some withstand fire exposure for longer periods, some multi-layered and gel-filled products act like a wall to stop the heat of a fire from passing through the glazing to the non-fire side, some have a lower time rating because they don?t pass the hose stream portion of American fire test standards. AFSG also found that there are safety film products that can be applied to wired glass to meet CPSC standards, and still pass fire tests for a 45-minute fire-rating. Wired glass manufacturers, however, have refused to acknowledge this technology.

Even with the number of fire-rated alternatives available in the U.S. today that provide impact safety, AFSG has been told that wired glass still has at least 85% of the U.S. fire-rated glazing market. In interviewing facilities administrators for schools and universities?the biggest class of wired glass users?as well as architects and local code officials all over the country, AFSG generally found most lacked knowledge about the variety of fire-rated options, and the widespread perception was that the alternatives are so expensive there?s no point in finding out specifics. But we also found school and university users that have flat-out banned wired glass and gone with the impact safe fire-rated alternatives, because they experienced injuries or high wired glass replacement costs. But most users, architects and code officials we talked to needed a short education in wired glass, and once they had accurate facts about its impact strength and the debilitating injuries it?s caused, they asked AFSG for information about alternative products.

Parents of recent wired glass victims took up this cause a year ago after realizing the wired glass safety threat is a national problem, but after watching wired glass forces use procedural technicalities and threats of legal action to gain yet another year of exempt status, they created AFSG to carry on in the future. Parents have designated AFSG to bring the public?s safety interests in this issue to the attention of federal and national model code regulators of consumer and building product safety who have both the authority and power to end the exemption and enforce compliance with the CPSC standard.

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Many people consider wired glass as a safety glass, but it is defineatly not, as Leo's document proves. It is uglier than crap, and extremely expensive in conparison to plate (annealed), tempered, laminate, or even plate with security film. Georgian Polished Wire (clear) we sell for approx. $15/sq. ft. (cdn$) and Georgian Cast Wire (frosted) for approx. $10.50/sq. ft. Not one glazier I know likes handling the crap, as you are gauranteed to get cut by it sooner than later. As for solar films it is common to see heat cracks in it caused by reflected/absorbed heat and imperfections amongst the wires, :thumb so yeah offer no warranty on these films.


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