Smoke detectors, sprinklers, and other technological advancements are credited for the life-saving role they play during home and office fires. Flame retardants are also an important part of the fire safety toolbox, yet they go unnoticed and in some cases are misunderstood. Flame retardants can provide an important layer of protection and help stop or slow the spread of fire by making buildings, furniture, cars, and planes more fire-resistant. Researcher and former firefighter instructor Dr. Matt explains his recent independent analysis drawn from a National Institute of Justice-funded arson study. The analysis speaks to the difference flame retardants can make when they’re used in household furniture.
The take-home message from this work is that over the past 50 years, fires in homes have decreased dramatically; at the same time, they’ve decreased the amount of flammable materials in homes dramatically. A major reason for the reduction of the fires is the fact that flame retardants have been incorporated into so many materials in the home. That stops the fires from happening. It used to be that cigarettes were the number one cause of these types of fires. That has declined because technology of cigarettes has changed. If you don’t continually draw on a cigarette now, it’s self-extinguishing.
If you have children, the highest risk of fire in the homes these days actually involves children playing with flammable materials—playing with lighters, playing with matches—and you don’t want them to be the victim of the fire. What we found in our study was that when we had a flame retardant in just the foam cushion, it delayed the free burning or flashover state of a fire by up to six to seven minutes. That’s a significant amount of time. During this time, you have lots of smoke being produced. The smoke triggers your alarm. You have time to evacuate the house. Without the fire-retardant foam, in three minutes the room is in flashover; so by the time you’re awake and ready to leave, the house has got such a large fire going, you can’t get out.
Two of our tests where we looked at a flame-retardant foam cushion with a normal cover, which is not fire-protective, and a non-protective foam with a non-protective cover. They both used a small ignition source. In this case, we used a source that’s the size of, say, a candle or a butane lighter. What we can see here, several minutes into the test, is that the flame on the unprotected couch or chair, is free burning. It’s putting out lots and lots of energy. As a result, all the other items in the room are going to catch on fire because heat release rate determines how fire spreads in a room.
Heat release rate is how fast it is burning. However, the flame-retardant foam cushion with the normal cover, you have a very small fire going. What we’re really seeing there is just the cover burning because the foam is protected. It’s much, much slower. Eventually there will be enough heat just in the cover burning that the foam will catch on fire, but it’s going to be much later into the event. You’ll have lots of time to escape or put the fire out. Basically, it’s a much safer condition.
An important lesson we learned from this study was that layered defense against fire is going to prevent these furnishings from catching fire. When you have a fire-protective cover over a fire-protective foam, the furniture doesn’t burn. Even with a large ignition source, the fires go out within a few seconds, and that’s important for home fire safety.
In another set of fire tests, we see two different chairs free burning. We use the large ignition source, 19 kilowatts, like a big wad of papers burning on a chair. For the one chair, it’s been fully-protected, you have a cover that’s flame retardant and the foam cushion that’s flame-retardant; and on the other chair, you have a case where there’s no fire protection. We can see that the unprotected chair is a very rapidly growing fire. You’re going to completely consume all the energy in that chair very, very quickly.
As a result, you’re releasing a lot of energy into the room, and everything else catches on fire. What I mean by that is your curtains catch on fire, your rugs catch on fire, anything else that’s flammable in the room will catch on fire—so it grows very quickly. You’re in flashover, and you can’t get out of the room; whereas the case on the fully protected chair, we can see that the flames are out. There’s some smoke. Basically, you had a non-event. There’s not a fire.
Thanks to this independent research, we have a better idea of the protection flame retardants provide in modern life. Like other elements of fire safety, flame retardants can help slow or prevent the spread of fire and help save lives