Safe Passage

Jul 1, 2007 12:00 PM, By Jeff Razwick

The infamous Seton Hall University fire of 2000 was back in the news this past January. The two young men responsible for the blaze were sentenced to prison after seven years of legal wrangling. Started intentionally in a student lounge, the fire quickly spread to become the worst residence-hall fire in U.S. history — three were killed, and 54 were injured.

For as much media attention as that fire drew, it hardly was an isolated incident. According to the National Fire Protection Association (NFPA), in an average year, 2,200 residence-hall fires occur across the nation. The Federal Emergency Management Agency (FEMA) says that the total number of fires in education facilities each year is about 14,000. Although the price in terms of lives and injuries can never be calculated, the hard cost to schools in property damage amounts to $220 million a year.

Balanced fire protection

What makes campus fire protection such a challenge is the unique dynamic of a student population. Nearly half of all school fires are the result of deliberate arson or foolish experimentation with fire by students. Fire-protection plans need to take into consideration the somewhat unpredictable behavior of the occupants.

In the case of Seton Hall, fire safety was almost entirely reliant on smoke detectors. Yet, according to Associated Press reports, the alarms in the hall were known to go off sporadically for no reason. With 18 false alarms the previous semester, residents learned to tune out the noise. When the alarms sounded the night of the fire, some students assumed it was one more false alarm and chose to ignore it. And the facility did not have sprinklers, which could have offered a second line of defense.

Planning needs to be more comprehensive and progressive. To provide adequate safety, a good fire-protection program must have three primary elements:

• Fire detection and suppression

  These are the most obvious components. Detection is the realm of fire detectors and smoke alarms, the early-warning systems that encourage evacuation.

  Suppression takes response to the next level. Extinguishers and sprinklers are installed with a goal of suppressing a blaze before firefighters reach the scene.

  Many schools go no further in their thinking than those two levels of protection. Some put as much faith in sprinklers as Seton Hall did in fire alarms. But that may not be enough.

  Both sprinklers and alarms are “active” systems. In order to work properly, they must be triggered, and they must be supplied with power or water. This leaves them vulnerable to error. What if a maintenance worker shuts off a water valve? What if batteries run down? What if a power outage occurs? What if sprinkler heads are painted over? Or what if the alarms go off and no one pays attention?

  Sprinklers and alarms save lives and dramatically reduce the risks associated with fire, and they should be installed strategically and widely. However, when they are less than 100 percent effective, it is critical to have other systems in place that can aid in the compartmentation of the fire and smoke.

• Compartmentation

  This is the process of dividing a building into smaller units using fire-resistant construction materials. Fire-rated windows, ceiling tiles, sheet rock, doors and other materials act as physical barriers that can keep a fire in a restricted space and prevent it from spreading too quickly. These “passive” fire-rated materials are on the job around the clock; they require no activation, and they can provide much-needed time for evacuation and for firefighters to get into the building safely.

  One important material in compartmentation is fire-rated glass, which can be found in doors, sidelites, transoms or windows.

  Fire-rated walls may have glass for many reasons: glass allows light farther into the building, provides greater visibility for people entering and exiting a space, and may offer more aesthetic appeal than a solid cinder block wall. Fire-rated glass most commonly is installed in corridors, lobbies, stairwells and other areas of a building that might become an escape route during a fire.

  Fire-rated glass has a proven track record of stopping flames and smoke. Standard float glass shatters at temperatures above 250°F (which structural fires surpass quickly). When the glass falls out of a frame, fire and smoke have a clear path to migrate throughout a building. Fire-rated glass can withstand temperatures as high as 1,600°F or beyond.

Examining the options

For many decades, the only glass capable of passing the testing process and earning a fire rating was polished wired glass. Although the glass cracks and melts during a fire, the wire mesh prevents it from falling out of the frame.

Although it performs well during a fire, wired glass can be broken relatively easily in the course of everyday use. The broken or exposed wires can then create snags, which have been known to cause serious injury. Over the past five years, national building codes have systematically eliminated the use of wired glass in “hazardous” locations — doors, sidelites and openings near the floor. Anywhere an impact-safety product is needed, wired glass no longer is an option.

Several new fire-rated products are now available that offer greater performance than wired glass in fire and impact safety. Strictly speaking, one of the newer materials isn't even glass — it is ceramic, which long has been esteemed for its ability to tolerate high temperatures. That's why modern ceramic materials can be found in everything from kitchen cooktops to car engines.

Once installed, fire-rated ceramic looks like ordinary window glass, yet retains its heat-resistant qualities. Some fire-rated ceramic products also can offer high impact-protection ratings (meeting the highest standard for glass, CPSC 16CFR1201, Category II). When desired, ceramic can be specified in insulated units to meet energy-code requirements for exterior applications. It also can be etched or sandblasted without affecting the fire rating.

In addition to withstanding fire, ceramics also have been tested to endure a less-expected enemy: water. When water from a sprinkler or fire hose hits glass that has been heated by a fire, most glass will explode or shatter. The glass cannot handle the stress of two different temperatures on its surface at the same time.

But because ceramic has a low expansion coefficient, it can tolerate thermal shock of that nature. Fire-rated ceramics have passed what is called the “fire hose stream test,” where glass that has been tested in a furnace is blasted with water from a fire hose while it is still hot. Ceramics are unaffected by the temperature change.

If water from sprinklers comes in contact with hot, non-rated glass during the fire, it will cause the glass to vacate the opening. Sprinklers generate large amounts of smoke as they extinguish fires, and once window glass has been broken, that smoke will spread freely. Because the majority of fire-related deaths are from smoke inhalation rather than burns, there is still cause for concern — even after the fire is out.

Wall talk

In some locations, it is necessary to do more than block flames and smoke. Some situations call for a barrier to heat. For example, stairwells are places where occupants potentially could become trapped for long periods of time. The heat from a fire needs to be blocked from such enclosed spaces as much as possible to keep conditions bearable. Typically, this has been done by using solid barrier walls with minimal glass.

Now that has changed. Glass fire walls offer two-hour fire ratings and unrestricted amounts of glass. Unlike most fire-rated glazing, glass fire walls are tested to the same standards as solid walls. That means that even though they are transparent, glass fire walls block the transfer of heat. Even when a fire is raging on one side of the glass, testing has shown that the opposite surface of the glass is still cool enough to touch.

Different glass fire walls are manufactured in various ways, but they all share a common concept. Multiple layers of glass sandwich an inert material that turns to foam during a fire. The foam obscures vision but blocks the heat of the fire.

Razwick is the director of business development for Technical Glass Products (TGP), a Kirkland, Wash.,-based supplier of fire-rated glass and framing systems, along with specialty architectural glass products.

2,200

Number of residence-hall fires across the nation in an average year.
Source: National Fire Protection Association (NFPA)

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