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Firefighter/EMT Safety, Health & Survival: The Basics of Modern Fire Behavior

Over the last decade, the fire service has seen a renewed emphasis on going back to basics. This movement can be justified in the simple fact that the number of fires has decreased 60% in the last 25 years, from 3,264,000 to 1,331,500, resulting in a perceived decline in firefighters' level of on-the-job experience.

This decline isn't only in skill levels, but also in the knowledge needed for effective decision making. The experience that's lost may be substantial, but departments are making a tremendous effort to address the loss of skills by focusing on areas associated with fire suppression.

Combine the emphasis of basics training with a constant focus on improving emergency response and a question comes to mind; are we adequately training our personnel to understand fire behavior on today's fireground?

Considering the topic of fire behavior and response times in the same discussion may seem careless, but these topics aren't mutually exclusive. As we try to travel to the scene quicker and employ firefighting techniques, are we more likely to encounter dangerous fire behavior conditions?

Changes in Fire Behavior

The emphasis on skills is obvious, but fire behavior has undergone drastic changes in the last 25 years. Petrochemicals and building construction has changed the game of fire suppression and is causing us to constantly reevaluate the strategies and tactics we employ on the fireground.

Fire chiefs can't rely on what firefighters were taught in recruit academy, because most fire-behavior curriculum is outdated at best and inadequate at worst. Most training programs don't emphasize the information that's currently available on fire behavior. But the fire service should pay more attention to the old adage from Sun Tzu: "Know your enemy and know yourself and you can fight a hundred battles without disaster."

Understanding fire behavior and the signs of danger will ultimately lead to better decision making on scene. Why? Because the rate at which a flashover occurs is exponential and if firefighters realize they're in a flashover event, they've realized too late.

Do firefighters really know when flashover is likely to occur? Do our members on the end of the hoseline have the ability to make rapid, educated decisions based on their initial size-up of fire conditions?

This concern isn't restricted to recruit firefighters; because the changes in fire behavior and the reduction in the overall numbers of fires, veterans need to be updated on fire behavior and those hostile fire events that may affect both the decisions that they make on scene and even their lives.

NFPA 921 defines flashover as a "transitional phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach its ignition temperature more or less simultaneously and fire spreads rapidly throughout the space resulting in full room involvement or total involvement of the compartment or enclosed area."

It's well documented that flashover is the point of untenable conditions in a room and survival for anyone in that room is very unlikely.

Response Times and Flashover Events

In addition to fire behavior, we should also make sure that all of our personnel understand the correlation to response times. The fire service is always attempting to decrease the total response times of its companies and is actually doing a good job.

According to the NFPA, regardless of region, season or time of day, structure-fire response times are generally less than five minutes half the time. The National Institute of Standards and Technology found that from time of ignition to actually putting water on the fire is 8:41 with a four-person crew.

What is really the importance of these numbers in relation to flashover?

Today's fires burn hotter and faster and many factors affect the rate of flashover; ventilated rooms will usually flashover in less than 10 minutes. There's also evidence from Underwriters Laboratories in which flashover was attained in a modern furnished room in three minutes, thirty seconds. The peak temperature during this experiment was 1300 degrees.

If firefighters aren't familiar with the conditions that lead to or are caught within a flashover, the results will be devastating.

All fire chiefs must ensure that fire behavior is the cornerstone of their training programs and personnel are trained and educated in the most up-to-date research.

This goes beyond basics training of how to put the wet stuff on the red stuff. This will require us to sit in classrooms, review research and simply observe fire behavior in acquired structures, flashover simulators and burn buildings. A lot can be learned from sitting and watching fire behavior and its associated dynamics.

This should be mandatory for all personnel, from the new recruit to the veteran company officers, because the game is changing and events such as flashover must be recognized. We must decrease response time but simultaneously ensure that our personnel are aware of what's happening while they are travelling and what they'll find when they arrive.

As fire chiefs, we must train and educate our personnel as if their lives depend upon it. They do!

Jake Rhoades, EFO, CFO, MS, MIFireE, is the deputy chief of special operations and training with the Rogers (Ark.) Fire Department. He serves as a board member for the IAFC's Safety, Health & Survival Section and the NFPA technical committee for risk management and is a state advocate for the Everyone Goes Home program.

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