Why A Flashover Kills

I read recently on Firehouse.com that a firefighter in Missouri was caught in a flashover while working at a house fire and was burned quite severely.

A flashover is the near simultaneous ignition of all combustible material in an enclosed area.

Flashover occurs when the majority of surfaces in a space are heated to the point (known as fire point) at which they give off flammable gases that are hot enough to sustain combustion. Flashover normally occurs at 500 °C (930 °F) for ordinary household combustibles.

You might be thinking, well, firefighters wear that protective clothing that should help them be okay in a flashover .....

In part that is true.  We wear that protective clothing when we enter burning buildings so we are protected from the heat the fire is generating.  But, it's not good enough to protect us from the temperature that exists when a flashover occurs.

Through my years of firefighting I have been taught and now teach to the firefighters on our department, that our protective clothing will keep us safe for about 2 seconds at a temperature nearing 1100 degrees F.  The temperature of failure may actually be a bit higher or lower, but it's still in that range of really-stinking-hot, regardless.

In my career, I've been at several house fires where the temperature was reaching the really-stinking-hot stages.  At one in particular, we searched the ground floor of a home - looking for the fire - but all we found was smoke and a tiny spot of visible flame around a wood stove chimney where it had started the ceiling on fire as it passed through the ceiling on it's way to the roof.

The fire was burning freely in the second story, so we advanced our hose up the stairs to attempt an attack on the fire.  As we advanced the hose up the stairs the temperatures increased significantly and at the top of the stairs it was so hot that I was feeling it quite well through my protective clothing.  We backed down the stairs and went to work ventilating the upper story of the home so we could release some of that heat.

We lost that house because of the advanced fire conditions in the second story and into the attic.  No one was hurt and a bunch of the owner's belongings were saved.  You win some, you loose some.

Firefighters train in how to deal with flashover in specially designed burn rooms.  It's an amazing thing so see the snaking flames travel the length of the burn room above your head, and feel the intense heat just above you, then learn a technique that could give you a few more seconds - maybe just enough time - to escape that intense heat.

Several years ago I was in Paradise, Utah at a live fire training exercise where a home was used for training burns, and then burned to the ground.  After the training and during the destruction burn, I was able to snap a photo through an open window of what it looks like when a flashover occurs as described above, nearly every combustible thing begins burning at once:

Paradise-(43)

Fire is deadly, it kills firefighters in their protective clothing just as easily as it does civilians - given the right temperatures and conditions.  The one big thing going for the firefighter is the breathing air carried on his/her back as they enter the smoke filled building.  The public generally doesn't have that tool, and therefore smoke kills more people in a fire than flames.

Rapid notification is the key to success in getting you and your family out of a burning structure, as well as giving firefighters a chance to respond before the fire has such a strong hold in the structure that it wins the battle.

Somehow, thankfully, the firefighter from Missouri was able to escape the heat and make it out alive.  Hopefully the treatment for his severe burns will be successful and he will suffer as little as possible.

Let's all be careful out there, and remember to keep your smoke detectors working properly!

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