Want to know how much time it can take for a fire to ignite an entire room?
As little as 166 seconds.
In a study conducted last summer by the Worcester Polytechnic Institute's (WPI) Fire Protection Engineering department, researchers set fire to a fully furnished 12-foot by 16-foot room to see how long it would take to achieve flashover, or the point at which all combustible material in a space catches fire.
They constructed a room according to building regulations and furnished it like any modern family might -- with wall-to-wall carpeting, a big, comfy couch, flowing curtains and all. But after setting fire to one part of the room, the researchers watched everything in the room go up in flames in less than three minutes.
"It is scary. This isn't even as stuffed as a real living room would be," said Kathy Notarianni, a professor in the Fire Protection Engingeering at WPI and one of the study's lead researchers. "That living room was sparsely furnished compared to an average living room."
But 30 years ago, the average living room wouldn't catch fire nearly as fast.
Thanks to the extra belongings that we cram into our homes and the synthetic materials our things are made of, researchers say, our homes are burning down faster than ever before.
And even beyond the stuff that fills our homes, firefighters say the cheaper, energy-efficient materials used to build our homes can make firefighting even more dangerous.
"Materials have changed," Notarianni said. "Think of the sofa in your grandmother's house and think of the sofa in your house. Your sofa is much bigger, it's full of stuffing, it's comfier, probably. … That comfy-ness is new materials that burn differently, release different chemicals, release different toxic gases."
Thirty years ago, products were made of natural fibers and solid wood. Now, our belongings are made of plastics and synthetic materials.
Not only that, but the sheer volume of things we own has grown tremendously, she said.
"Our houses are stuffed. We don't have one TV, we have four or five TVs," she said. "The kids have more clothes, more toys, more plastic toys. ... You used to get a couple of toys a year, now you get a couple of toys a week."
But when fire strikes, all our favorite things become fuel.
In the 1970s, a National Institute of Standards and Technology (NIST) study found that people have 17 minutes to escape a fire after their smoke alarm goes off. But when the institute repeated the study in 2004, it found that the escape window had shrunk to just three minutes.
"What's different now is we have houses that are getting larger," said Dan Madrzykowski, a fire protection engineer in NIST's engineering laboratory. "And during the past 50 years, we've introduced a lot of synthetics into the home."
Not only are people fitting more so-called fuel into their expanding homes, he said, they're designing homes that make it easier for oxygen, which fires need to survive, to spread.
Traditional ranch- or Cape Cod-style homes featured smaller, separated rooms. But, nowadays, he said, it's not unusual to find single-family homes with wide, open spaces that extend from one end of a home to the other.
"There's less compartmentation. It's beautiful for living, you have better air circulation," Madrzykowski said. "But when you think about it from a fire perspective, there's nothing to stop the smoke and toxic gases from spreading throughout that entire house."
Robert Leonard, a volunteer firefighter for more than 20 years and spokesman for the Firemen's Association of the State of New York, said that over the course of his career, he's seen new materials alter the flare-ups firefighters are called to put out.
"From the firefighter on the ground's standpoint, fires are hotter, they're burning probably more quickly ... [and] not ventilating as easily," he said.
Cheaper and lighter manufactured lumber (made of wood chips and shavings glued together) might be better for the builders. But, he said, they don't hold up in a fire as well as the 2-inch by 4-inch or 4-inch by 6-inch solid wooden beams that they replaced.
He also said the windows installed in many modern and newly renovated homes can complicate matters further.
Thermo pane windows may be more energy-efficient and insulating, but they also trap the heat when fires ignite indoors. And thick hurricane windows, which are built to resist high-velocity winds, can also prove resistant to the pry bars and axes firefighters often need to break into a burning building.
In response, Leonard said, they've had to modify their tactics and training. Firefighters more carefully plan their entry into buildings and have become more aware of construction materials and designs in their area so they know different buildings' vulnerabilities.
"We've always had a coordinated attack but it's even more coordinated," he said. "There's a much more aggressive look at the timing of the fire."
Not all fires are of the extreme variety -- most fires take place in the kitchen and during times when residents are awake and able to extinguish them quickly. And when fires are starved of oxygen, they won't necessarily flashover in just three minutes.
But fire researchers warn that it's critical to maintain working smoke alarms and even consider installing residential sprinkler systems.
And ultimately, when a fire starts, experts say residents need to act as fast as they can before firefighters arrive.
"If occupants are not out of their buildings within two to three minutes of the alarms going off, then they may never actually get out," said Russ Thomas, director of fire research at the National Research Council in Canada. "The real secret is, when the alarms go off, get out."