Safe glass breakthrough.
THE BATTERING RAM hung just a few feet from the wired glass window. A 4-by-4-inch beam of wood several feet long with 45 pounds of lead weight attached, it hung horizontally, suspended by hooks and ropes from a joist in the Eugene School District maintenance barn.
Maintenance Supervisor Mark Anderson pulled a rope down, drawing the battering ram back and then let go. The beam - think of it as a stiff-armed teen - flew forward and smashed the wired glass easily, leaving a halo of shards and wire.
Wired glass looks strong, but it's fragile. It's designed to stop fire, not physical force. But it's been misunderstood for decades, construed as a safety glass that could take impact the same way tempered and laminated glasses do.
"You look at it and you say, `God, that's got to be tough,' ' said Jerry Razwick, president of Technical Glass Products, a Seattle firm that sells glass.
But it's not. Unlike other window glass, most commonly a quarter-inch thick, wired glass sandwiches the wire between one-eighth-inch panes, which require less force to break, Razwick said. It doesn't meet the impact standards set by the federal Consumer Product Safety Commission.
The Eugene district had a recent reminder of wired glass's frailties when a middle school student put his hand through a panel in October and sustained injuries that required surgery and will require months of physical therapy to heal (see related story below).
Like school districts throughout the country, Eugene has plenty of wired glass in its buildings - about 16,000 square feet of it. And school officials say it's time for the stuff to go.
The goal is to replace it with newer products that are strong enough to resist the impact of rambunctious students while still keeping fire from spreading. Replacing that much wire glass at first appeared to be an expensive proposition - perhaps as much as $1 million.
But that figure has come down to a ballpark range of between $180,000 and $600,000, according to facilities manager Bill Hirsh. The lower numbers came from a closer analysis of the replacement costs and the range of products available for the retrofit, Hirsh said.
And that's what brought Anderson, the maintenance supervisor, building safety officer Harlan Coats and several other district staff to the maintenance barn two weeks ago.
They wanted to test one class of products, polyvinyl film, which coats and strengthens wired glass and costs much less than new glass.
After breaking a plain piece of wired glass with the rigged-up battering ram, they methodically tested another 12 pieces of wired glass, each one specially treated with a film designed to strengthen the glass.
The result? Every single piece of treated glass, whether coated on one side or both sides, did better than the plain wired glass.
The tests can't be considered rigorous and showed only small performance differences among the brands, Anderson said. While the weighted wood beam shattered every glass panel it hit, it didn't penetrate any of them. The broken glass stayed lodged in the film.
And that was the key for Harlan Coats.
"I don't care if it gets broken," he said after the tests. "I just don't want somebody putting his hand through it."
Safe glass advocate Greg Abel said he's pleased that the school district is making the effort. Like the Bethel School District, which finished a retrofit of its schools a year ago, and Springfield, which has begun similar work, Eugene is trying to get out in front of the problem.
Up until two years ago, Abel operated a small business that manufactured educational materials for disabled students. Then his son, a University of Oregon student, put his hand through wired glass during a basketball game at the UO student recreation center. Jarred Abel suffered permanent nerve damage and has filed suit against the manufacturer. Meanwhile, his dad has become a full-time advocate for safe glass, a one-man band to change building code regulations governing its use.
In 1977, the Consumer Product Safety Commission gave wired glass manufacturers an exemption from the impact standards required of other glass products - because it was the only glass available that could be used in walls and doors designed to slow the progress of fire. The weakness of the glass is well-documented.
But are injuries from wired glass more common than injuries associated with other kinds of glass?
Nobody knows for sure.
Wired glass has been used successfully around the world for decades with relatively few accidents, said Valerie Block, who chairs a committee of the American National Standards Institute, an independent testing agency that is considering toughening impact standards for wired glass.
"It's not just like walking into clear glass; the wire acts as a deterrent," she said.
Opponents want safety exemptions for the glass removed, since there are other products on the market that slow the progress of fire and meet the impact standards, she said.
The Consumer Product Safety Commission maintains injury and death data on thousands of products based on reports from 100 hospital emergency rooms across the country. While the agency lists separate accidents and injuries from products such as scooters and in-line skates, it has only one category for glass injuries. The reporting hospital might make a special note of the type of glass responsible for an injury, said commission spokesman Ken Giles. Otherwise the agency doesn't track it.
"I'm not saying we don't have some injuries," Giles said. "The data staff have looked for wired glass incidents and found relatively few."
But Abel contends it's more than a little ironic that the agency that collects the injury data doesn't seek out information that would help answer the question about the safety of wired glass.
"It's totally backward," Abel said. "You have a problem and you know it's a problem, and you don't track it?"
Abel said when he went looking for reports of wired glass injuries, he was able to learn of 86 accidents, through word of mouth and e-mail contacts, during a three-month period.
In Oregon alone, he said, there have been about 25 such accidents, he said. But not one of the Oregon incidents would show up in the Consumer Products Safety Commission data because none of Oregon's hospital emergency rooms is on the list that reports injuries to the agency, Abel said.
Abel's nonprofit group, Advocates for Safe Glass, lists the 86 accidents he's discovered on its Web site, www.safeglass.org. The examples date back to 1977, with the most serious accidents resulting in amputation of the arm.
Abel and other industry advocates have succeeded in getting some code requirements changed.
At the national level, the International Code Committee, an organization working to standardize building codes across the country, will revise its 2003 code recommendations to exclude wired glass in educational and athletic buildings.
In Oregon, the Building Codes Division will consider barring wired glass in schools at a meeting to be held this month or next.
But such changes refer only to new construction. There are no laws addressing retrofits, Abel said. That makes the districts' efforts all the more commendable, he said.
Eugene plans to start retrofitting three schools - Jefferson, Monroe and Kelly middle schools - in January, Anderson said.
Only about 8,000 square feet of the district's wired glass is located in doors or windows that building codes say must be fire rated, most commonly between interior rooms. The other 8,000 square feet is located in places that should more properly have glass that is impact resistant and doesn't need to slow the advance of fires - exterior doors, for example.
For fire-rated locations, the district will keep the wired glass, coating it on both sides with the film it recently tested. Where only safety glass is needed, the district will choose either tempered or laminated glass, Anderson said.
In Bethel, wired glass was replaced last year at Willamette High School, Cascade and Shasta middle schools, and Clear Lake, Danebo, Irving and Malabon elementary schools at the urging of Eugene state legislator Vicki Walker, district spokesman Craig Hawkins said. The replacement costs ran to about $10,000, he said.
Springfield is midway through a similar retrofit, with film coatings already installed on wired glass at Thurston High School.
Springfield High School is next on the list, and other schools are still being evaluated, interim Superintendent Steve Barrett said. Springfield expects to spend about $55,000 on the retrofit, he said.
The costs are higher in Eugene, which has more than 40 school buildings.
The total cost will become clearer as work is done at the middle schools, Hirsh said.
"We still don't know about installation and first-time costs," he said. What is also still unclear is which of the film coatings is rated for fire locations. The district doesn't want to use a product on the wired glass that will strengthen it but ruin its fire-slowing properties.
The price range for the options is broad, with film costing between $3 and $6 a square foot and fire-rated impact safety glass running as high as $70 a square foot, he said.
The money to pay for the work will come from the $116 million bond approved by voters last May for new construction and maintenance. That bond includes an emergency allowance, Hirsh said.
"It's for items that come to our attention that shouldn't or couldn't wait as much as a year," he said.
A GLASS PRIMER
Wired glass: Wire mesh sandwiched between 1/8-inch panes of glass. The wire holds shards in place when the glass shatters, slowing the progress of flames, smoke and gas. For decades, it was the only product approved for fire-rated doors and windows. But it's weaker than regular glass and the Consumer Product Safety Commission granted the glass an exemption from impact standards in 1977. A 1996 court challenge to that exemption failed.
Tempered glass: Glass strengthened through a heating-cooling process to be four times more impact-resistant than nontempered glass. When it does break, it shatters into small beads. It's commonly used in the side windows of cars. Not for fire-rated locations.
Laminated glass: Two pieces of glass with a polyvinyl interlayer bonded together under heat and pressure. May crack upon impact but the broken glass sticks to the plastic layer sandwiched in the middle, which keeps shards from flying. In multiple layers, it's strong enough to stop bullets. Not for fire-rated locations.
Fire-rated safety glass: Different products include ceramic glass that is both impact resistant and slows the progress of fire anywhere from 20 minutes to more than an hour. It's also the most expensive glass.
- Primary Glass Manufacturers Council
Harlan Coats of the Eugene School District's facilities staff holds up a sheet of wired glass that was coated with a polyvinyl material and was smashed with a swinging 4-by-4-inch timber as part of an extensive test of different brands of coatings. The material prevents a person's hand from penetrating the glass and suffering injuries. THOMAS BOYD / The Register-Guard
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|Title Annotation:||Schools test, install coatings to help stabilize wired glass; Schools|
|Publication:||The Register-Guard (Eugene, OR)|
|Date:||Dec 2, 2002|
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