Flashover!

May 1, 2003
You're pushing a hoseline down a hallway or working your way around a room doing a quick search when suddenly the entire area bursts into flame. The temperature suddenly has risen to over 1,800 degrees Fahrenheit. Your turnout gear begins to smoke and then catches fire. Your facepiece glazes over and your faceshield or eyeshields start to become a molten sheen. Any exposed skin immediately starts to burn. You frantically try to get away, but the fire appears to be everywhere. If you're not too deep into the room or if you can back out quickly, then maybe just maybe you'll survive, but you will be burned.

What has happened to you is called flashover. This phenomenon occurs when ALL of the combustible materials within the confines of a room or area have reached their ignition temperatures and total combustion occurs. The temperatures within the space will suddenly escalate from a few hundred degrees to as much as 2,000F. Unlike a backdraft, this event occurs at a point between the growth stage and the fully involved stage. Also, there is not a pressure wave associated with this occurrence.

There are cues associated with the development of this situation. They are an advanced stage of burning upon arrival, sudden buildup of heat and rollover. How well you recognize these cues and how well you determine why you should be in this environment will dictate whether you return safely from the job or become a statistic.

We all need to become more adept at performing size-up. I'm not talking about the 13-point system so often used for exam purposes. I'm talking about what are you seeing upon arrival and what do you know about the building before you received the alarm. How well do you read smoke? Do you know the difference between trapped smoke and that which is pushed by high heat? Can you differentiate between smoke involved with plastics and other furnishings versus that which involves structural members? Do you know how weather, temperature and humidity affect the movement and action/texture of the smoke? As you look at flames do you recognize when a fire has plenty of oxygen already or is starving but still plenty hot? If you can't answer yes to all of the above, get some more training before you respond again.

In the over 200 years of organized fire protection in this country, only the gear and equipment have changed. We still send people down the hall to put out the fire. In my 30-plus years of fire service, the evolution of personal protective equipment (PPE) has reached high technological levels. Perhaps too high. We've encapsulated our members to the point that we are actually robbing them of many of their natural senses.

When I began my service, we wore metal helmets. They had ear flaps and a chin strap. The biggest advantage was when you were lying on your stomach (we wore filter masks or Chemox if it was a basement) and your ears began to burn, you knew it was time to get out or back up. Now we wear Nomex hoods, full PPE, including turnout bunker pants, self-contained breathing apparatus (SCBA) and gloves. Your bunker gear may protect you up to 1,600F - but your skin fails at 124F. So we've taken away the first line of defense, the body's ability to tell you it's time to regroup or leave the area.

We pride ourselves at being aggressive. "Getting the wet stuff on the red stuff" as soon as possible is the way to prevent the fire from growing has long been the mantra for the fire service. This theory no longer is valid at all times, in my opinion. Modern building construction materials and techniques might have you ambushed before you get into the building. The use of plastics and truss construction lead to quicker failures and hotter fires faster. We don't know when the fire started, we only know when we were called.

I'm not promulgating the concept of not going into a structure. I only do that when a fire involves a vacant building. I am endorsing the process of slowing down and evaluating the issue before you enter the immediately dangerous to life and health (IDLH) environment where you will see little or nothing at all. As you advance the line it never hurts to open the nozzle and give a few short bursts of water toward the ceiling as you go down the hall or enter a room. This simple act can very well interrupt the fire growth cycle and prevent a flashover.

Another tip for officers is to remove one glove and as you move along on your knees raise that hand above your head. If you are forced to bring it back down to your side rapidly because of the heat, it might be a good idea to evaluate where you and your crew are and decide if you really need to be there. Remember, the fire never calls time out just because you're not ready or unprepared for the fight. Protect yourself at all times and stay safe.

Michael L. Smith, a Firehouse® contributing editor, is a 30-year veteran of the District of Columbia Fire Department, currently deputy chief/suppression and shift division commander, commanding all fire, EMS, hazmat, special operations and special events activities in the District on shift. He is a 30-plus-year fire service veteran and is a graduate of the Executive Fire Officers Program at the National Fire Academy. Smith is a Certified Municipal Manger (CMM) from George Washington University and has degrees in fire science, construction management and public administration. He holds a journeyman's card with United Brotherhood of Carpenters and Joiners, and lectures nationwide on fire service topics, including management, command, rapid intervention, building construction, and strategy and tactics for all types of buildings. This column originally appeared on Firehouse.com.

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