Guest Post – Flashovers Are Occurring More Frequently. Know How To Be Prepared!

Fact: Flashovers Are Occurring More Frequently. Know How To Be Prepared!

By Captain Craig Nielsen, Los Angeles Fire Department

Flashovers kill more firefighters than anything else and what’s worse than that shocking piece of information is that flashovers are happening more frequently than ever before. As a 28-year veteran of the fire service, I’ve been involved in flashover survival trainings since 1998. It’s important to ask the right questions – questions that once answered have the ability to save lives. For example, what is a flashover and why are so many more occurring these days as opposed to in the past? How can firefighters identify them, and what steps can they take to ensure they are safely managing them?

I’ll address the answers to these questions and more in a free “Understanding Flashovers” webinar sponsored by Draeger Safety, on November 10, 2011 at 8 PM EST. Firefighters and chiefs interested in participating in this educational session can register at We’ll also have a live Q&A so your specific questions can be addressed. For now, I’d like to touch on some of the biggest questions the webinar will explore in more depth.

What is a Flashover?
Walton and Thomas define it as “the transition from a growing fire to a fully developed fire in which all combustible items in the compartment are involved in fire” although a more simple definition is “the stage when contents and gases are heated to their ignition temperatures and flames break out almost all at once.” This is the most dangerous stage of fire development and poses the most risk for firefighters – so knowing what it is and how to spot it is critical to safety.

What Can I Look Out For?
While flashovers have typical signs and symptoms, some of them are difficult to spot. Just knowing what they are can help you act appropriately and safely. Things to watch out the most for are:
Heat build-up. When the fire is low in intensity and spreading slowly, combustibles and flammable gases are heated to the point of ignition.
Look up. You can go into a structure and see from one end to the other, unaware accumulated gas in the ceiling space above may be ready to ignite.
Rollovers. These are often the preemptive sign that a flashover is going to occur and they’re identified when you see flames “rolling” across the ceiling; where heated gas tends to rise. If you witness rollovers, cool down those gases effectively and get out of the building.
Pressurized smoke. If you are observing smoke exiting the exterior of a structure, look for what kind of pressure buildup is associated with that smoke.

Why Are So Many Flashovers Occurring?
The increasing occurrence of flashovers has been covered at great length in print, online and broadcast media and it certainly deserves the attention. Here are some reasons for the uptick of flashovers:
Better turnout gear. Firefighters are putting themselves in harm’s way unknowingly because firefighters are often reliant on the protective capabilities of their gear.
Better insulation: Homes are better insulated which is great for the heating bill, but not so great for firefighters. Thermal feedback is occurring more rapidly.
Combustible items: Plastics and synthetics create a lot more BTUs. Know what you’re going into and look for signs outside of the building that can offer clues for what you’ll encounter inside.

With flashover occurrences increasing, knowing more about this phenomenon is crucial for all chiefs and firefighters, to avoid injury or death. Don’t forget to join me on November 10 for more information.

About the Author
Craig Nielsen, a 28-year veteran of the fire services, is a Captain with the Los Angeles Fire Dept. He has served as a Live Fire Training Officer, Driver Training Instructor, Career Guidance Counselor & Instructor of Record. Nielsen has been assigned to the most active fire station in the country for over two years, with 20+ responses per day. He is a California state-certified Fire Instructor and Fire Officer, and Emergency Medical Technician. He has been a Dräger Swede Survival instructor since 1998.