Archive for the ‘Random Thoughts’ Category

Last week I had the opportunity to attend the Florida State Fire College’s Live Fire Training Instructor (LFTI) Course held at the Oregon Public Safety Academy. This delivery is part of an effort by the state’s Department of Public Safety Standards and Training (DPSST) to evaluate options for improving safety during live fire training. DPSST and the Oregon Fire Instructor’s Association are evaluating curriculum and varied approaches to delivering training to assist fire service agencies safely and effectively deliver live fire training.

The Florida Experience

Deputy Chief Dave Casey, Seminole Tribe of Florida Fire Department (former Chief of Fire Standards and Training, Florida State Fire Marshal) presented an overview of the origin and evolution of live fire instructor training in Florida.

On July 30, 2002 Lieutenant John Mickel and Firefighter Dallas Begg lost their lives in a live fire training exercise conducted in  Poinciana, Florida (see Figure 1). LT Mickel and FF Begg were performing primary search ahead of the attack line during a live fire evolution in an acquired structure. Horizontal ventilation resulted in ventilation induced flashover while the search team was in the fire compartment. This training exercise was conducted in compliance with many of the provisions of NFPA 1403. However, instructors did not adequately assess the fire compartment in terms of potential fire behavior and the required fuel load to meet the desired learning outcomes for the evolution. For more information on this incident see the Florida State Fire Marshals Report and NIOSH Death in the Line of Duty Report F2002-34.

Figure 1. Acquired Structure-Poinciana, Florida

Note: Florida State Fire Marshal Photo

This incident resulted in considerable discussion of how to ensure that instructors delivering live fire training understood the provisions of NFPA 1403 and how to safely and effectively deliver live fire training. The Florida Live Fire Training Taskforce held its first meeting in June of 2004 and established the following mission:

This curriculum is intended to deliver a comprehensive live fire instructor training program, within a safe and controlled environment, in accordance with NFPA 1402, NFPA 1403 and NFPA 1500.

In May 2005, the Florida Legislature passed the LT. John Mickel & Dallas Begg Act, requiring certification to conduct live fire training in the state of Florida and was signed into law by the Governor in June of the same year. The first pilot delivery of the Live Fire Training Instructor course was held in January 2006.

LFTI

Participants in this course must be certified instructors and must complete pre-course readings and a pre-test prior to attending the training program. The 40-hour course addresses the provisions of NFPA 1403 on a chapter by chapter basis:

• Administration, Referenced Publications, & Definitions
• Acquired Structures
• Gas-Fired Live Fire Training Structures
• Non-Gas-Fired Live Fire Training Structures
• Exterior Props
• Exterior Class B Fires
• Records & Reports

This 40-hour course provides instructors with a detailed look at the standard and the opportunity to apply the standard in a variety of activities including development of live fire training plans, evaluation of acquired structures, and management of live fire training delivery.

Evaluation and Critique

The instructional staff delivering this program was extremely knowledgeable and provided the participants with a solid grounding in both the provisions of the standard and the rationale for the design of the course. In addition, considerable effort was extended to ensure that the participants understood the physiological impact of live fire training on the participants and importance of maintaining hydration and managing heat stress. This is critical as the majority of firefighters who die during live fire training suffer from heat stress, heart attack, or some other underlying medical cause.

While the LFTI course provided excellent information and is an essential element in training instructors to deliver live fire training, it does not go far enough. The LFTI course does not (yet) address the most critical issue which is the participants understanding (or lack thereof) of fire dynamics.

Emphasizing the value of NFPA 1403 in a videotaped interview (American Heat, September 2003) Dave Demers (who investigated the Boulder, Colorado firefighter live fire training fatalities that gave rise to the development of this standard) stated that with the standard “you don’t need to think, you simply need to follow directions”. While this perspective was not shared by the instructional staff delivering the LFTI course, it does point to a major disconnect between the standard, course content, and predominant cause of traumatic fatalities during live fire training.

Recommendations

The short term solution to ensuring live fire instructors have an understanding of and can apply NFPA 1403 and practical fire dynamics is to expand course content to include compartment fire behavior and related content that is applicable to other types of live fire training (e.g., exterior props and Class B fires). However, this knowledge is required by more than instructors. The long term solution is to expand the level of knowledge required by firefighters and fire officers across the board. This will likely require revision of the applicable professional qualifications standards and related curriculum (no small task from a political perspective).

Thanks!

I would like to extend my thanks to Florida State Fire Academy instructional staff Susan Schell, Joe Garda, Dave Casey, Dan Godfrey, and Richie Leitz for their delivery of the LFTI and ongoing efforts in support of firefighter safety.

Update

Tuesday is another milestone in my career. Effective June 30, 2009, I will no longer be employed by Gresham Fire & Emergency Services. Due to severe fiscal constraints, the entire Training, Safety, & EMS Division is being eliminated. Lieutenant Chris Baird previously went to the line as a company officer and EMS Coordinator John Stouffer and I are being laid off. Fortunately I had six months notice and have been working towards transition to a new role in a different organization (yet to be determined).

While many would approach being laid off a bit differently, I chose to have the department’s traditional coffee and cake send off (Figure 2).

Figure 2. Chief Lewis Presents Ed’s Badges

Note: Photo by Lieutenant Chris Baird

This is not a dead end, but simply a fork in the road. Stay tuned for news of the next chapter in the adventure!

References

American Heat (2003, September). Live Fire Training Fatalities.

Florida State Fire Marshal, Bureau of Fire Standards and Training. (2002). Incident Investigation of Two Firefighters Deaths During a Training Fire; Poinciana, Florida; July 30, 2002. Retrieved June 28, 2009 from http://www.fldfs.com/sfm/pdf/InvestFFDeath_FST_20020730_20030411.pdf.

National Fire Protection Association (NFPA). (2007) NFPA 1403 Standard on Live Fire Training Evolutions. Quincy, MA: Author.

National Institute for Occupational Safety and Health (NIOSH). (2003) Death in the line of duty report F2002-34. Retrieved June 28, 2009 from http://www.cdc.gov/niosh/fire/pdfs/face200234.pdf.

Safety Week 2009

June 14-20, 2009 is Fire & EMS Safety, Health, and Survival Week. CFBT-US urges you to take this week to examine your own habits and behaviors and common practices in your fire service organization with a critical eye and identify ways in which you can reduce your risk and improve the effectiveness of fireground operations.

IAFC Recommendations

The International Association of Fire Chiefs (IAFC) has published a list of recommendations to encourage individual and organizational responsibility for safety.

Safety: Emergency Driving (enough is enough-end senseless death)

1. Lower speeds-stop racing to the scene. Drive safely and arrive alive to help others.
2. Utilize seat belts-never drive or ride without them.
3. Stop at every intersection-look in all directions and then proceed in a safe manner.

Health: Fire Fighter Heart Disease and Cancer Education and Prevention

1. Don’t smoke or use tobacco products.
2. Get active.
3. Eat a heart-healthy diet.
4. Maintain a healthy weight.
5. Get regular health screenings.

Survival: Structural Size-Up and Situational Awareness

1. Keep apprised of different types of building materials and construction used in your community.
2. Develop a comprehensive size-up checklist.
3. Always complete a 360° walk of the structure to collect valuable, operational decision-making information.
4. Learn the practice of reading smoke.
5. Be familiar with the accepted rules of engagement.
6. Learn your accountability system and use it.
7. Master your tools and equipment.
8. Remain calm and concentrate.

Chiefs: Be the Leader in Safety

1. Become personally engaged in safety and make it part of your strategic vision for the department.
2. Be willing to make the tough decisions regarding safety policies and practices and their implementation.
3. Hold members of the organization accountable for their safety and the safety of those with whom they work.
4. Ensure that resources are available to accomplish activities safely and effectively.

Additional Considerations

In addition to the recommendations made by the IAFC, I would like to offer several additional recommendations and revisions to the IAFC’s list.

Health: Remember that products of combustion present both short and long term health effects. Don’t breathe smoke and minimize exposure to products of combustion by using care in handling contaminated equipment and clothing and cleaning it promptly after use.

Survival: Develop a solid understanding of practical fire dynamics. In addition to understanding building construction (B) and reading smoke (S), use the entire B-SAHF (Building-Smoke, Air Track, Heat, & Flame) approach to reading the fire. Remember that size-up and dynamic risk assessment are an ongoing process conducted by everyone on the fireground!

Chiefs: Not only must you hold your members accountable. They must be able to hold you accountable as well. Lead by example!

Still Waiting to Hear from You!

In an earlier post, I encouraged you to construct a personal concept map of fire behavior indicators, starting with building factors. As a way of collaborating on this project, you can follow edhartin on Twitter and Tweet Back on this question with factors that you think should be included in the concept map. No response as of yet! Take a minute and revisit Reading the Fire: How to Improve Your Skills and consider engaging in this project. I need your help to make this work.

Ed Hartin, MS, EFO, MIFireE, CFO

Congratulations!

I would like to offer my congratulations to my two friends and colleagues Inspector John McDonough, ASFM of the New South Wales Fire Brigades and Acting Inspector Shan Raffel, CIFireE, EngTech, ASFM of Queensland Fire Rescue on receiving the Australian Fire Service Medal (AFSM) for distinguished service to their nation’s fire service. This is the second accolade for Shan in the last several months as he was recognized as a Companion of the Institution of Fire Engineers (IFE) for his work as national president and his tireless work for IFE Australia. Outstanding work gentlemen, honors well deserved!

Figure 1 ASFM Recpients Shan Raffel (left) and John McDonough (right)

B-SAHF! Master Your Craft

In Reading the Fire: B-SAHF, I introduced the B-SAHF (Building, Smoke, Air Track, Heat, and Flame) conceptual framework for reading the fire and have subsequently provided a series of video clips and photos to provide an opportunity to exercise your skill in reading the fire. While looking at video, photos (and actual incidents) may help build your knowledge and skill, different types of practice and knowledge building can also further your professional development.

Concept Maps

A concept map is a graphic tool for representing knowledge (Novak & Cañas, 2008). The map illustrates concepts and their relationships to one another (similar to an electrical circuit diagram or road map). Concept maps use a hierarchical form (similar to an organizational chart) with general concepts at the top and details further down. Mind maps are a similar tool often used in brainstorming that use a radial hierarchy with a tree-like hierarchy branching out from the center. I draw on both of these approaches in describing fire behavior indicators. A radial hierarchy is used as the foundation, but other relationships are illustrated and concepts can be interconnected in a variety of different ways.

A key step in improving your ability to read the fire is to think about what you should be looking for. Identifying key indicators and thinking about what they mean can be an important step in developing and improving your knowledge and skill. I find that this is an ongoing process as I continue to add to and refine my fire behavior indicators concept map. This map is not a fireground tool or a checklist of things to look for, but serves as a representation of my understanding and learning. While I am willing to share this map (Ed’s B-SAHF Map v5.2.1), it is more useful for you to build your own, representing your own understanding of these indicators and concepts.

Concept maps can be created using a pencil and paper, Post-It notes and an easel pad or white board, or using a computer with drawing software or a program specifically created for concept mapping. At one point or another, I have used each of these tools and find that they all have advantages and disadvantages. The tools you use are not as important as the mental process of collaborating with others and creating your map.

The Starting Point

Without getting bogged down an a long discussion of the educational and psychological foundations for concept mapping, it is important to understand that development of concept maps supports meaningful rather than rote learning. Rote learning often involves simple memorization. Meaningful learning requires three conditions (Ausubel, 1963).

• Concepts must be clear and presented with common language and examples connected to the learner’s prior knowledge.
• The learner must have relevant prior knowledge. Note that the learner does not require expertise, but needs sufficient knowledge to make sense of the concepts involved.
• Most importantly, the learner must choose to learn in a meaningful way.

Many firefighters struggle with creating mind maps (at first) because much of fire service training focuses on rote learning. However, I find that this challenge can easily be overcome if firefighters recognize the value of exploring the key fire behavior indicators and their relationships to one another.

Developing a concept map starts with a focus question that specifies the problem or issue that the map is intended to help resolve. The fire behavior indicators (FBI) concept map starts with the following focus question:

What building, smoke, air track, heat, and flame indicators
provide clues to current and potential fire behavior?

It is important to remember that a concept map is never finished. After you develop the first draft, it is always necessary to revise the map to increase clarity or add important concepts that you discover as work continues. For example, my FBI Concept Map is on Version 5.2.1, indicating five major revisions and 21 minor revisions or additions over seven years!

Knowledge Soup

The best concept maps are not developed in a vacuum. Collaboration with others can help us identify additional information and provides ideas that we may not have thought of on our own. For example, the current version of my FBI concept map started as my collaboration with Shan Raffel. However, it has evolved to include suggestions from hundreds of CFBT course participants.

Propositions or ideas developed by a group of learners may be thought of as ingredients in a kind of “knowledge soup” (Cañas, Ford, Hayes, Brennan, & Reichherzer, 1995, p. 4). The learners share the ingredients and each cook their own variation on the soup by constructing their own understanding. One way to approach this is to brainstorm key concepts and ideas before beginning the process of organizing the information and drawing the map.

Technology and Information Sharing

We have an advantage today that firefighters in previous generations did not have. Technology provides unparalleled opportunity for collaboration and learning. For example, this blog provides me with an opportunity to communicate and share information with firefighters around the world in a matter of minutes. In addition to my twice weekly blog posts, micro-blogging using the CFBT-US Twitter page provides a simple and easy method to rapidly share information on a daily (and in some cases hourly) basis.

Recently I have been reading a series of blog posts titled 31 Days to Build a Better Blog on Problogger. This stimulated my thinking about different ways to leverage technology to share information within the fire service and more particularly the compartment fire behavior community. Twitter may provide a simple means for collecting the ingredients needed for the knowledge soup necessary to develop and improve our respective fire behavior indicators concept maps.

This process could be started posting a question focused on one element of the FBI Concept map such as: What key building factors that impact on fire behavior can be used as indicators of current and predicted fire behavior? Readers can then respond (Tweet Back) with brief statements (no more than 140 characters) that identify the factors. All readers would then have access to this information when constructing the Building Indicators segment of their FBI Concept Map.

Another challenge is actually drawing the concept map (some of us are more graphically inclined or skilled than others). Bubble.us is a simple and easy to learn tool that provides a way to organize information as a concept map and share the work with others by e-mail, on the web, or embedded in a web page.

Figure 2. Bubbl.us Concept Map

Use of this software is free (you simply visit the bubbl.us web page, sign up and start creating your map. You can share your map with others to read or you can give them permission to edit the map. While I have not used this software extensively, it appears to be extremely easy to use and an excellent tool to simplify the process of drawing concept maps.

Where to from Here?

All very interesting, but how does this help us improve our ability to read the fire? Originally I had thought about using the “31 Days” concept to reading the fire. However, it will likely take a bit longer than that.

My next post will propose that we begin with an examination of building factors that influence fire behavior and which may serve as useful indicators in situational assessment. In the mean time, visit the CFBT-US Twitter page and respond to the question about building factors! Follow me for regular updates (you can also subscribe to an RSS Feed to receive information in a feed reader or via e-mail).

Each month I will move to the next element in the B-SAHF organizing scheme for fire behavior indicators until we have completed the entire FBI concept map. However, feel free to work ahead!

Ed Hartin, MS, EFO, MIFireE, CFO

References

Ausubel, D. (1963). The psychology of meaningful verbal learning. New York: Grune and Stratton.

Cañas,A., Ford, K., Hayes, P., Brennan, J., & Reichherzer,T. (1995) Knowledge construction and sharing in Quorum. Retrieved June 7, 2009 from http://www.ihmc.us/users/acanas/Publications/AIinEd/AIinEd.pdf

Novak. J. & Cañas, A. (2008). The theory underlying concept maps and how to construct and use them. Retrieved June 7, 2009 from http://cmap.ihmc.us/Publications/ResearchPapers/TheoryUnderlyingConceptMaps.pdf

Most of the provisions outlined in National Fire Protection Association (NFPA) 1403 Standard on Live Fire Training Evolutions, deal with mitigating the risk of traumatic injury or fatality. The standard addresses training prerequisites, but does not speak to medical and physical capacity prerequisites. The standard does specify that:

• The instructor-in-charge is responsible for provision of rest, and rehabilitation (inclusive of medical evaluation)
• Emergency medical services must be available on-site, and
• The instructor-in-charge is responsible for overall fireground activiey to ensure correct [emphasis added] levels of safety.

While the emphasis on live fire training safety has been placed on traumatic injuries and fatalities, this is not the predominant cause of live fire training line of duty deaths. Between 1994 and 2003, 65% of live fire training related fatalities resulted from physiological stress and heart attack (Grimwood, Hartin, McDonough, & Raffel, 2005)

NIOSH recently released Death in the Line of Duty Reports 2008-30 and 2008-36, both of which examined incidents in which firefighters lost their lives during or immediately after live fire training. It is easy to glance at these reports and think that this is just another heart attack with the same recommendations as all the other report. However, I encourage you to stop, read these two reports, and give some thought to what this information means to you on a personal level.

NIOSH Report 2008-30

On August 9, 2008; Captain Sean Whiten (Age 47) was leading a team of students during live fire training in a purpose built burn building. After completing an interior attack, Captain Whiten complained of being tired but otherwise had no complaints. Medical evaluation conducted as part of the rehabilitation process showed elevated pulse and blood pressure, but this was consistent with participation in a strenuous training activity.

After rehab, Captain Whiten was relaxing by his vehicle when he went into cardiac arrest. Instructors and students began CPR and applied a automatic external defibrillator prior to the arrival of an advanced life support ambulance. Paramedics initiated advanced live support procedures and transported Captain Whiten to the hospital where resuscitation efforts continued until he was pronounced dead by the attending physician.

An autopsy conducted by a forensic pathologist discovered that Captain Whiten suffered from coronary artery disease and had ventricular hypertrophy (LVH) and cardiomegaly, conditions which increase the risk of sudden cardiac death. The Captain also had mild elevation of his carboxyhemoglobin (COHb) level, but it is unclear if this had any influence on his heart attack and sudden cardiac death. The Captain’s risk factors for CAD included male gender, age over 45, high blood cholesterol, and obesity. However, he had been cleared by his primary care physician to engage in a fire department physical ability test.

NIOSH Report 2008-36

On July 6, 2008 Firefighter Rufus Brinson (Age 50) was teaching a class involving live fire training at a local community college. After several evolutions under high ambient temperature 34.4^o C (94^o F) and high relative humidity (58%), including a search drill conducted using hot smoke in a purpose built burn building, Firefighter Brinson indicated that he was not feeling well and took a break in the air conditioned cab of the engine. Another instructor took over teaching for the next evolution while Firefighter Brinson operated the pump. While refilling the apparatus tank after the final evolution, he collapsed next to the apparatus.

An instructor initiated CPR and requested an ambulance. The ambulance was staffed with intermediate level emergency medical technicians who requested response of a paramedic level unit. Transport was initiated prior to the arrival of paramedics who met the ambulance enroute to the hospital and initiated advanced life support procedures. Resuscitation efforts continued at the hospital until Firefighter Brinson was pronounced dead by the attending physician.

An autopsy conducted by the medical examiner listed congestive heart failure as the cause of death and severe coronary atherosclerotic disease and hypertensive heart disease as contributing factors. Firefighter Brinson was also found to have left ventricular hypertrophy (LVH) and cardiomegaly. Risk factors for CAD included male gender, age over 45, smoking, overweight (but not obese), and limited aerobic exercise. Firefighter Brinson had not had a medical exam by a physician in seven years.

Common NIOSH Recommendations

While both of these reports contains unique recommendations based on the circumstances involved, there are also several common recommendations:

Provide pre-placement and annual medical evaluations to fire fighters consistent with National Fire Protection As­sociation (NFPA) 1582, Standard on Comprehensive Occupational Medical Program for Fire Departments, to determine their medical ability to perform duties without presenting a significant risk to the safety and health of themselves or others.

Incorporate exercise stress tests following standard medical guidelines into a Fire Department medical evaluation program.

Ensure fire fighters are cleared for return to duty by a physician knowledge­able about the physical demands of fire fighting, the personal protective equipment used by fire fighters, and the vari­ous components of NFPA 1582.

Phase in a comprehensive wellness and fitness program for fire fighters to reduce risk factors for cardiovascular disease and improve cardiovascular capacity.

Perform an annual physical performance (physical ability) evaluation to ensure fire fighters are physically capable of performing the essential job tasks of structural fire fighting.

Provide fire fighters with medical clearance to wear a self-contained breathing apparatus (SCBA) as part of a Fire Department medical evaluation program.

These recommendations are no surprise. It is commonly known that firefighting is a physiologically stressful activity and that working in a high ambient temperature environment increases that stress substantially. Firefighters must be well and fit in order to safely and effectively operate in realistic training and on the fireground.

Responsibility

Who is responsible for ensuring that firefighters are medically and physically capable of engaging in firefighting operations? On one hand, you can make a reasonable argument that it is the fire department’s (employer’s) responsibility. One of the foundations of occupational safety and health regulation is the employer’s responsibility to provide a place of employment which is free from recognized hazards that are causing or likely to cause death or serious physical harm. However, is this solely the employer’s responsibility?

In examining this issue, I will put things in a personal context. I am a male, over 50, have a family history of heart disease, and last ago was diagnosed with hyperlipidemia (high cholesterol). While not grossly overweight, over the last 10 or 12 years my body mass index had crept up and outside the optimum. In addition, my work schedule and graduate studies had negatively impacted my workout schedule and reduced my aerobic exercise considerably. When I had my annual medical physical as a hazmat technician, the occupational medicine physician indicated that I should talk with my primary care physician about my cholesterol level lose some weight, and get more aerobic exercise. Several weeks later, I sat with my dad (a retired fire chief) as he died from congestive heart failure (at age 92). He had retired due to a heart attack the year I started my fire service career. The time that I spent with him over the last week of his life gave me a great deal to think about.

While my employer should (and does) provide medical physicals, respirator qualification, physical ability assessment, and the facilities and time to work out, I am the one responsible for action. Since last summer, I have lost 15.9 kg (35 pounds), substantially improved my aerobic fitness, and reduced my cholesterol to near optimal level. While I had not noticed the degradation in my physical capacity (other than to figure that I was getting old), I have noticed a significant improvement. I feel better on a day-to-day basis and find myself less fatigued when delivering live fire training.

Fire service organizations have a responsibility to their members to provide medical/physical assessment and wellness/fitness programs. However, each of us also has a responsibility to ensure that we are medically and physically qualified for the work we are doing. Take care of yourself and look out for the people you work with!

References

National Fire Protection Association (NFPA). (2007). Standard on live fire training evolutions. Quincy, MA: Author.

National Institute for Occupational Safety and Health (NIOSH). (2008). Death in the line of duty (Report Number 2008-30). Retrieved June 4, 2009, from http://www.cdc.gov/niosh/fire/pdfs/face200830.pdf

National Institute for Occupational Safety and Health (NIOSH). (2008). Death in the line of duty (Report Number 2008-36). Retrieved June 4, 2009, from http://www.cdc.gov/niosh/fire/pdfs/face200836.pdf

Grimwood, P., Hartin, E., McDonough, J., & Raffel, S. (2005). 3D firefighting: Training, techniques, and tactics. Stillwater, OK: Fire Protection Publications.

The theme for the 2009 meeting Institution of Fire Engineers (IFE) Compartment Firefighting Special Interest Group (SIG) in Sydney, Australia was Finding the Common Ground. The 15 participants represented 12 fire service organizations from Australia, New Zealand, Sweden, the UK, Spain, Croatia, China, Canada, and the United States.

Figure 1. 2009 IFE Compartment Firefighting SIG Participants

Understanding & Application

The dominant common theme identified by the participants is the need for firefighters and fire officers to have a solid understanding of fire dynamics and the ability to apply that knowledge in an operational context. Achieving this goal cannot be accomplished simply by delivering a course or training program, it requires a fundamental shift in perspective and ongoing effort to support individual and organizational learning.

Simply achieving knowledge of fire dynamics and skill in task and tactical activity is necessary but not sufficient. Achieving increased safety and effectiveness requires that firefighters and fire officers effectively apply this knowledge on the fireground. Facilitating this transfer from training to operational context is a challenge is a significant challenge.

Dr. Stefan Svensson of the Swedish Civil Contingencies Agency posed the question: How do we get learners to understand the differences between training fires and “real fires”. This is an interesting question in that training conducted in a container, burn building, or acquired structure is in fact a “real fire”, but has considerably different characteristics than a fire occurring in a house, apartment, or commercial building. Improperly designed training may provide the learner with an inaccurate perspective on the fire environment which can lead to disastrous consequences. The challenge is managing risk while developing a realistic understanding of fire behavior.

What is the Difference?

Compartment fires in the training environment differ from those encountered during emergency operations differ on the basis of compartment characteristics, fuel, ventilation profile, heat release rate, and time scale. In addition to differences related to fire dynamics, firefighters and fire officers also encounter psychological stress resulting from a sense of urgency, organizational and community expectations (particularly in situations where persons are reported to be trapped in the building).

Other than acquired buildings, structures used for fire training are generally designed and built for repetitive use and not for regular human habitation. Structural characteristics that make a durable live fire training facility are considerably different than most if not all other structures in the built environment. Density, thermal conductivity, and specific heat of training structures can be considerably different than a dwelling or commercial structure, which has a significant impact on fire behavior.

The ventilation profile of a purpose built prop or burn building is also likely to have significantly different compartmentation and ventilation profile than a typical residential or commercial structure. Live fire training facilities often (but not always) are designed with burn compartments. This speeds fire development and minimizes both initial and ongoing cost. However, fire behavior and the impact of fire control tactics can be considerably different in a large area and/or high ceiling compartment. Many modern structures are designed with open floor plans that are challenging to duplicate in the training environment. Energy efficient structures limit ventilation (air exchange), while training structures are often quite leaky, particularly after extensive use. This can have a significant influence on development of a ventilation controlled burning regime and influence of ventilation on the concentration of gas phase fuel in smoke. Failure of glass windows in ordinary structures should be anticipated, as this changes the ventilation profile and resulting fire behavior. Training structures on the other hand provide a more consistent ventilation profile as durable (e.g., metal) windows do not present the same potential for failure.

While structural characteristics, compartmentation, and ventilation differ between typical structures in the built environment and those used for live fire training, one of the most significant differences lies in the types, quantity, and configuration of fuel.

National Fire Protection Association (NFPA) 1403 Standard on Live Fire Training is fairly explicit regarding fuel characteristics and loading for live fire training evolutions. Most of these provisions can be tied directly to incidents in which participants in live fire training exercises lost their lives. Unfortunately, there are not the same provisions in fire and building codes. Fuel load is considerably higher in most residential and commercial occupancies than is typically used in live fire training, even in advanced tactical evolutions.

Together these differences provide considerably different fire dynamics between the training and operational environments. How much and in what ways does this impact on the effectiveness of compartment fire behavior training (CFBT)?

Fidelity

As discussed, CFBT, even when conducted in an acquired structure does not completely replicate fire conditions encountered in an operational context. All CFBT involves simulation. The extent to which a simulation reflects reality is referred to as fidelity:

The degree to which a model or simulation reproduces the state and behavior of a real world object or the perception of a real world object, feature, condition, or chosen standard in a measurable or perceivable manner; a measure of the realism of a model or simulation; faithfulness… 2. The methods, metrics, and descriptions of models or simulations used to compare those models or simulations to their real world referents or to other simulations in such terms as accuracy, scope, resolution, level of detail, level of abstraction and repeatability. (Northam, n.d.)

CFBT can involve a wide range of simulations, from the use of photos and video, non-fire exercises, small scale props such as doll’s houses, single and multi-compartment props, and burn buildings, and acquired structures. Each provides differing degrees of fidelity.

Fidelity can be described in a number of different ways. One fairly simple approach is to examine physical and functional fidelity (see Figure 2). Physical fidelity is the extent to which the simulation looks and feels real. Functional fidelity is based on the extent to which the simulation works and reacts realistically.

Figure 2. Two-Dimensional Fidelity Matrix

Note: Adapted from Fidelity Versus Cost and its Effect on Modeling & Simulation (Duncan, 2007)

While describing fidelity of a simulation as low, moderate, or high, this is likely to be inadequate. A more useful description of fidelity includes both qualitative and quantitative measures on multiple dimensions. But what measures and what dimension? In a compartment firefighting simulation, key elements of physical fidelity will likely include fire behavior indicators such as Building, Smoke, Air Track, Heat, and Flame (B-SAHF). Important aspects of physical fidelity would include the characteristics of doors and windows (e.g., opening mechanism), hose and nozzles, and influence of tactics such as gas and surface cooling on fire behavior.

On the surface it makes sense that increased fidelity would result in increased effectiveness and transfer of knowledge and skill. However, it is important to remember that “All models are wrong, but some models are useful” (Box & Draper, 1987, p. 424). The importance the various aspects of fidelity depend on the intended learning outcome of the simulation. In fact, a simulation that focuses on critical contextual elements may be more effective than one that more fully replicates reality.

Figure 3. Door Entry Drill

For example, teaching the mechanics and sequence of door entry procedures (see Figure 3) might be more effectively accomplished using a standard door without smoke and flame than under more realistic live fire conditions. On the other hand, reading fire behavior indicators at the door and effectively predicting interior conditions is likely to require substantively different elements of context. However, at this point, we simply have unsupported opinion and in some cases anecdotal evidence of the effectiveness or lack of effectiveness of current training practices. The key to this puzzle is to clearly define the intended learning outcomes and identify the critical elements of context that are required.

Questions Remain

The IFE Compartment Firefighting SIG identified the need for a greater emphasis on fire behavior training at all levels (e.g., entry level firefighters, incumbent firefighters, and fire officer) as well as ongoing professional development and skills maintenance. However, a number of interesting questions remain, including:

• What are the most effective methods of developing firefighters understanding of compartment fire behavior?
• What is necessary to effectively facilitate transfer of this knowledge from training to the operational context?
• What level of fidelity is necessary in live fire training do develop and maintain critical skills?
• How can technological simulation (computer or video based) simulation be used to augment live fire training to maintain proficiency?
• To what extent might non-live fire simulation (e.g., CFBT for the Wii) be used to develop compartment firefighting competencies?

Professor David Morgan of Portland State University observes that “A successful research project requires two things: Meaningful research questions and appropriate means to answer those questions” (Morgan, 2005, p. 1-2). One of the greatest potential benefits resulting from collaboration between members of the IFE Compartment Firefighting SIG is the integration of the skills of academics and practitioners, scientists and firefighters. During the 2009 workshop, SIG member Steve Kerber from Underwriters Laboratory (formerly with the National Institute for Standards and Technology) emphasized the importance of scientists and engineers doing research with, not simply for the fire service. This has the potential to not only identify meaningful questions, but also to provide the knowledge and skills necessary to answer them.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Northam, G. (n.d.). Simulation fidelity – Getting in touch with reality. Retrieved May 2, 2009 from http://www.siaa.asn.au/get/2395365095.pdf

Box, G. & Draper, N. (1987). Empirical model-building and response surfaces. San Francisco: Wiley.

Duncan, J. (2007). Fidelity versus cost and its effect on modeling & simulation. Paper presented at Twelfth International Command and Control Research and Technology Symposium (12^th ICCRTS), 19-21 June 2007, Newport, RI.

Morgan, D. (2005). Introduction [to integrated methods] (Unpublished Manuscript). Portland, OR: Portland State University.

I had intended to write today’s post simply about the IFE Compartment Firefighting Special Interest Group in Sydney, Australia. However, the recent keynote presentation at the Fire Department Instructors Conference (FDIC) by FDNY Lieutenant Ray McCormack claiming the fire service needs a “culture of extinguishment not safety” cannot pass without comment.

I wonder how much of the commentary on the web is based on quotations pulled from LT McCormack’s Keynote Presentation or simply extension of comments by others. If you want to know what he said, listen to his entire presentation.

Too Much Safety

I disagree with much, but not all of what LT McCormack had to say. One of the memorable quotes from this speech is “Too much safety makes Johnny a poor leader and a terrible rescuer.” What does this really mean?

I believe that LT McCormack cares deeply about the firefighters and fire officers he works with and does not want to see them injured or killed. However, he recognizes that there the fireground presents inherent hazards. Completely eliminating firefighter injuries and fatalities on the fireground would require that we not go to fires. On this point, LT McCormack and I are in agreement.

LT McCormack indicates that safety should come from proficiency in the craft of firefighting. On this point I substantively agree, but suspect that the LT and I would disagree on the full range of knowledge, skills, and work practices that should be included. For example, while the LT poked fun at air management, I believe that working effectively while maintaining respiratory protection is a fundamental component of effective and skillful firefighting.

Learning from Experience

Introducing the LT, Chief Bobby Halton stated that “Experience without reflection or evaluation is simply interesting”. Reading the stories of firefighters who have died in the line of duty while fighting fires inside burning buildings, I find that the common elements are frequently the same. In some cases, firefighters die because they over extended themselves in attempting to rescue a civilian occupant. However, in other cases they died because they did not recognize and control the hazards presented by the situation.

We tend to be reactionary, making policies, rules, and procedures based on prior bad outcomes. However, this practice often fails to address the root cause of the problem. I believe that the concept of two-in/two-out is sound and providing a rapid intervention team (RIT) when firefighters are in a hazardous environment is a solid idea. However, it does not address the root causes of firefighters becoming lost or trapped inside burning buildings. Does this mean that having a RIT is too much safety? I think not. However, failing to ensure firefighters’ knowledge of fire behavior and building construction is too little safety! Safety is not simply about policies, programs, and procedures; it must be integrated into our work practices. This is not to say that we do not need policies, programs, and procedures, but they must be sound and integrated with skillful and effective work practices.

LT McCormack undoubtedly recognizes that some civilian occupants lose their lives before the fire department arrives and is not advocating extension of search into areas of the building that contain a fully developed fire. The major question is where to draw the line between offensive and defensive operations. How much risk is acceptable to save a savable life, how much risk is acceptable to save savable property? This is a question that each fire department, each fire officer, and each firefighter needs to answer.

Trapped or dead firefighters do not save civilian occupants or property. Firefighters working to save their comrades likewise do not save civilian occupants or property. Working safely allows everyone on the fireground to contribute to our purpose of being there. Too much safety is not the problem.

Identity and Values

LT McCormack states that an emphasis on safety is based on fear and results in firefighters risking loss of their identity as firefighters and the values of courage, determination, and pride. On these points I disagree.

There is a difference between fear and understanding the hazards presented on the fireground. There is a difference between unthinking reaction and well though and skillful tactical action. The values of courage, determination, and pride apply equally to service to our citizens and service to our members. Sometimes it is necessary to say, no, the risk is too great. I suspect that in some of these situations the LT and I would agree and in others we would not. That is the challenge.

Culture of Extinguishment

LT McCormack states “We do not need a culture of safety; we need a culture of extinguishment… If we put out the fire, safety is accomplished for everyone on the fireground”. This is absolutely correct. However, I suspect that the LT and I might disagree about the application of this important concept or how it should be supported.

• Effective risk management results in saving savable lives while not compromising the safety of firefighters.
• Search supported by effective fire control and tactical ventilation is more likely to succeed than search that is not.
• In some cases firefighters should take the fire first, rather than focusing on primary search (as controlling the fire will eliminate the threat to both firefighters and occupants).

At the start of his presentation, LT McCormack stated “my name is Ray and I like to go to fires”. Much of what we do is driven by our identity as firefighters and the fact that we enjoy our work. While selfless sacrifice for others is honorable, sacrifice because of thoughtless action or ignorance is simply tragic.

“Too much safety makes Johnny a poor leader and a terrible rescuer”. I disagree. Safe performance makes Johnny a good leader and an effective rescuer.

Take 30 minutes and listen to LT McCormack’s presentation and give some thought to how you view safety and effective fireground performance.

Ed Hartin, MS, EFO, MIFireE, CFO

Greetings from Australia

As I mentioned in an earlier post, I am in Sydney, Australia to participate in the Institution of Fire Engineers (IFE) Compartment Fire Behavior Special Interest Group (SIG) International Instructor’s Workshop and present at International Firefighting Safety Conference 2009 which is being held in Sydney and Perth, Australia. I am energized by the unique opportunity to be involved with these two events.

In 2008, Dr. Stefan Svensson of the Swedish Civil Contingencies Agency (formerly Raddningsverket or the Swedish Rescue Services Agency), had an idea to invite a number of instructors, fire officers, and researchers with an interest in compartment fires to Sweden. His purpose was to “see what would happen” if he put a dozen or so highly motivated, passionate, and generally opinionated fire service professionals from around the world who share a common interest in the same room for a couple of days. Stefan in an interesting guy, he is a fire protection engineer who conducts research on fire behavior and firefighting operations and teaches at the national Fire College in Revinge. However, he is also an part time firefighter and crew commander assigned to a fire station in a small village outside Malmo, Sweden.

I was fortunate enough to be one of those invited to Stefan’s experiment. Last spring we traveled to the Fire College in Revinge, Sweden and spent several days listening to presentations participating in a wide range of live fire training exercises and observing demonstrations of fire control techniques and training methods. Interestingly, we found that we had much in common (both personally and professionally) and all learned a great deal.

At the workshop we discussed how this collaborative effort could be continued. Shan Raffel from Queensland, Australia, suggested forming a SIG within the IFE as one way to help maintain momentum and provide an means to bring the range of fire service professionals engaged in research, study, and application of knowledge related to fire behavior. As a significan number of the group were IFE members, this semed like an excellent idea. At the time, Shan was the President of the Australia Branch of the IFE and served as the principle organizer and driving force behind accomplishing this task and bringing the group to Australia for our next meeting.

Working Collaboratively

I had an interesting dinner conversation with Stefan Svensson Saturday night. We were talking about the importance of our network, working together, and sharing knowledge. Neither scientists nor firefighters have a complete understanding of fire behavior; both have part, but not the entire picture. However, working together, we are more likely to be asking the right questions and gain an improved understanding.

Stefan shared that he had tried to figure out how many firefighters there are in the world. Likely this estimate was far from accurate, but the number is quite large. He observed that many firefighters do not collaborate with others outside their own agency (and in some cases even within their own agency). We puzzled over why this was the case. All of us are engaged in essentially the same types of work (at least in the firefighting domain), we use the same technology (water, hose, nozzles, tools, ladders), and share the same passion for our work. Why is it often so difficult for agencies and individuals to work across borders (local, national, or international)?

Over the last year, a number of the participants in the first international workshop have maintained contact and collaborated using e-mail and Skype (free voice over internet protocol voice and video phone). I am equally as likely to collaborate with colleagues in Sweden, Australia, the UK, Croatia, Canada, or Chile as those in neighboring jurisdictions. While it is great to travel, meet face to face and share information, today’s technology provides a great (and considerably less expensive) way to do so. For example, I had never met Shan and John McDonough when Paul Grimwood and I worked with them to write 3D Firefighting: Training, Techniques, & Tactics. We accomplished that task simply using e-mail. I think that with current technology (e.g., Skype) this would have been an easier task.

My next post will be following the conclusion of the International Fire Instructor’s Workshop and I will share our experiences and accomplishments. The challenge for you is to look for opportunities to share your knowledge, collaborate with and learn with others and develop a broader community of practice as a fire service professional!

Ed Hartin, MS, EFO, MIFireE, CFO

In May 2008 I was fortunate to be one of 12 instructors, fire officers, and fire scientists who met in Revinge, Sweden at the invitation of Dr. Stefan Svensson of Räddnings Verket (Swedish Rescue Services Agency). Stefan was intrigued by the idea of putting a dozen or so leading fire service professionals with an interest in fire behavior, but divergent perspectives on strategies and tactics in the same room. His research question was to “see what would happen”. Stefan invited participants from Sweden, the United Kingdom, Australia, Poland, Germany, Spain, France, and the United States to this unique event.

Figure 1. Participants in the 2008 International Fire Instructors Workshop

What happened was that we found tremendous commonality of interest and commitment to improving firefighter safety and fire protection across the world. Surprisingly, while we often disagreed on technical issues and discussion was at times quite vigorous, we left the workshop with greater understanding and a stronger bond.

Special Interest Group

As an outgrowth of our meeting in Sweden, we formed a special interest group (SIG) under the umbrella of the Institution of Fire Engineers. The Compartment Fire Behavior Special Interest Group serves to construct knowledge by integrating fire behavior research, instruction, and practical application.

The first meeting of this newly formed SIG will be held 27-28 April 2009 in Sydney, Australia with the theme Finding the Common Foundation. Participants from around the world will be examining compartment fire behavior training principles and practices to find common ground and identify best practices. Immediately following the workshop, the participants will be presenting at the International Firefighting Safety Conference in Sydney on 29 April through 1 May and in Perth on 4-5 May 2009.

International Firefighting Safety Conference

The conference theme is Protecting the Protectors with a wide range of presentations on fire science, strategy and tactics, and fire behavior training.

I will be making two presentations in Sydney and one in Perth:

• How Much Science? (Sydney)
• Extreme Fire Behavior: Understanding the Hazard (Sydney)
• Fire Development in a Compartment (Perth)

Additional information and a complete outline of the program is available on the conference web site .

Critical NIOSH Recommendation

On Thursday morning, I will be somewhere over the western Pacific, but use WordPress’ automated publishing feature to upload a post on NIOSH Report F2007-28 on the line-of-duty deaths of Captain Matthew Burton and Engineer Scott Desmond of the Contra Costa Fire Protection District while conducting primary search at a residential fire. In a groundbreaking first, NIOSH has identified the need for improvement in Firefighter and Fire Officer Professional Qualifications Standards in the area of fire behavior knowledge:

Standard setting agencies, states, municipalities, and authorities having jurisdiction should: consider developing more comprehensive training requirements for fire behavior to be required in NFPA 1001 Standard for Fire Fighter Professional Qualifications and NFPA 1021 Standard for Fire Officer Professional Qualifications and states, municipalities, and authorities having jurisdiction should ensure that fire fighters within their district are trained to these requirements.

Following the conference, I will publish a series of posts from a CFBT-US case study on this incident and the potential influence of the ventilation tactics used on the extreme fire behavior phenomena that occured.

Reports from the Workshop and Conference

I will be posting on information presented at the workshop conference over the next two weeks.

Ed Hartin, MS, EFO, MIFireE, CFO

In Fire Gas Ignitions and Language & Understanding: Extreme Fire Behavior, I pointed out the ambiguity in definition of terms related to extreme fire behavior. In the structural firefighting context, the term extreme fire behavior is used to identify phenomena that result in rapid fire progression and present a significant threat to firefighters. Rapid fire progression may involve transition to a fully developed fire (e.g., flashover) or it may involve a brief, but significant increase in energy release (e.g., backdraft, flash fire, smoke explosion).

One way to begin the process of reducing the ambiguity surrounding extreme fire behavior phenomena is to establish a framework for organizing and classifying extreme fire behavior phenomena.

Organizing Concepts

The organization and classification framework presented in this post is based on the following general concepts:

• Extreme fire behavior involves a rapid increase in heat release rate (HRR).
• The increase in HRR can be sustained or it may be relatively brief.
• Brief increases in HRR may or may not result in overpressure inside a compartment or building.
• Extreme fire behavior may occur in a fuel or ventilation controlled burning regime
• Concentration (mass fraction) of fuel in the gas phase influences the nature of extreme fire behavior.
• Depending on existing or developing conditions, extreme fire behavior may be initiated by reaching critical HRR, an increase in ventilation, or a source of ignition.

It is likely that there are additional concepts or criteria that may prove useful in the process of organizing and classifying extreme fire behavior. However, these concepts provide a starting point for this process and discussion.

Classification by Outcome

At the highest level, extreme fire behavior phenomena are classified on the basis of the duration of increased HRR. If increased HRR is sustained and the fire enters a (relatively) steady state of combustion, the phenomena would be classified as a Step Event. However, if the increase in HRR is brief and not sustained, the phenomena would be classified as a Transient Event.

A rapid increase in HRR results in increased temperature of the atmosphere inside the compartment. As temperature increases, the gas (i.e., air and smoke) volume within the compartment will expand. If the gas volume inside the compartment is confined and cannot expand, pressure will increase, in some cases significantly! Transient events are classified as Explosive (resulting in a significant overpressure) or Non-Explosive (not resulting in a significant overpressure). Explosiveness is in part a result of the mixture of gas phase fuel and air present in the compartment and the extent to which combustion is confined.

Classification of extreme fire behavior phenomena on the basis of outcome are illustrated graphically in Figure 1.

Figure 1. Outcome Classification

Classification by Conditions

Additional clarity can be obtained by examining extreme fire behavior phenomena on the basis of requisite conditions for occurrence. However, it is important to keep in mind that conditions are rarely uniform in structure fires. Different compartments (e.g., habitable spaces, voids) can have dramatically different conditions in burning regime, fuel concentration, oxygen concentration, and temperature.

In a compartment with sufficient openings, flashover can occur prior to fire growth becoming significantly limited by available ventilation. However, a majority of extreme fire behavior phenomena occur when the fire is in a ventilation controlled burning regime. As compartment fire development becomes limited by ventilation, not all of the gas phase fuel resulting from pyrolysis is burned. This excess pyrolizate increases both the mass and concentration of fuel within the compartment (and other compartments as smoke spreads through the building). Concurrently, with increased fuel concentration, oxygen concentration decreases.

Provided a source of ignition with sufficient energy, gas phase fuel/air mixtures within the flammable range can be ignited. However, if the fuel/air mixture is too rich, additional air must be introduced and mixed with the fuel in order for combustion to occur.

For extreme fire behavior phenomena occurring within a ventilation controlled burning regime, the following factors can be used to further define the nature of the phenomena:

• Fuel Concentration
• Oxygen Concentration
• Extent of Confinement

The combination of fuel/air mixture and extent of confinement define what type of initiating event (contact with source of ignition, increase in ventilation, or both) will be necessary for the extreme fire behavior to occur.

Graphical Representation

It is often easier to see how things are organized using a visual model or diagram. However, it is not so simple to capture a high level of complexity in a simple drawing. Figure 2 illustrates the concepts presented in this post regarding classification of extreme fire behavior phenomena.

This is a work in progress and feedback is greatly appreciated!

Ed Hartin, MS, EFO, MIFireE, CFO

Language is Important

Language has a substantial influence on what and how we think. “What a man cannot state he does not perfectly know, and conversely the inability to put his thoughts into words sets a boundary to his thought” (Newbolt, Bailey, Baines, Boas, Davies, Enright, et al., 1921, p. 20).

While the authors of this statement were focused on English language education in English schools in the 1920’s, the underlying concept applies equally well today. Language is the foundation of understanding. While this is true in day-to-day life, it is equally (or even more) important when dealing with scientific concepts and phenomena related to firefighting.

While construction and fuel loading vary to some extent, fire services around the world are challenged by similar fire problems in the built environment. Each of us faces the same processes of compartment fire development and extreme fire behavior phenomena such as flashover, backdraft, and smoke explosion. However, our understanding and communication about these important processes and phenomena are limited by lack of a common language. In many cases terms have more than one definition. In addition, definitions are often unclear and imprecise.

Shared Concepts

In philosophy, ontology is the study of the nature of reality, categories of being, and their relations; what entities can exist and how they can be grouped, related within a hierarchy, and divided based on their similarities and differences. Ontology is a system of concepts that provides a shared vocabulary that can be used to describe and think about a particular domain.

We do not really have an ontology that encompasses fire behavior phenomena such as flashover, backdraft, smoke explosion, and the like. As Dr. Stefan Svennson so astutely observes, it is complicated and there may not always be a clearly defined differences between phenomena. However, going back to the opening paragraph of this post, I contend that a shared language is necessary for us to understand and mitigate the hazards we face as a result of rapid fire progress. Hopefully this post will engage you in this ongoing effort.

Extreme Fire Behavior

Terms such as flashover, backdraft, and smoke explosion are often used to describe phenomena involving rapid fire progression in compartment fires. Currently accepted definitions provide a starting point for developing improved clarity. As a starting point, I have examined definitions of extreme fire behavior phenomena from the following sources:

1. International Standards Organization (ISO)
2. National consensus standards organizations (e.g., National Fire Protection Association, Fire Protection Association)
3. International or national professional associations (e.g., Institution of Fire Engineers, Society of Fire Protection Engineers)
4. Recognized texts

Consider the similarities and differences in the following definitions and give some thought to the questions that follow.

Flashover: 1) Stage of fire transition to a state of total surface involvement in a fire of combustible materials within an enclosure’ (ISO 13943, 2008, 4.156). 2) A transitional phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach 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 (NFPA 921-2007).

Discussion: This transition is often assumed to take place between the growth and fully developed stages. However, neither the ISO nor NFPA definition specifies this. In addition, while the NFPA definition indicates that this transition is extremely rapid (i.e., more or less simultaneously), the ISO definition does not describe the speed with which the transition to total surface involvement occurs.

• Is the occurrence of flashover limited to the transition between growth and fully developed stages of fire development?
• Can flashover result from increasing ventilation to a ventilation controlled fire (vent induced flashover)? If yes, how does this differ from backdraft?
• Can a fire reach the fully developed stage without transitioning through flashover?

Backdraft: 1) Rapid flaming combustion caused by the sudden introduction of air into a confined oxygen-deficient space that contains hot products of incomplete combustion. In some cases, these conditions can result in an explosion (ISO 13943, 2008, 4.21). 2) A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion (NFPA 921, 2008, 3.3.14).  3) A phenomenon that occurs when a fire takes place in a confined area such as a sealed aircraft fuselage and burns undetected until most of the oxygen within is consumed. The heat continues to produce flammable gases, mostly in the form of carbon monoxide. These gases are heated above their ignition temperature and when a supply of oxygen is introduced, as when normal entry points are opened, the gases could ignite with explosive force (NFPA 402, 2008).

Discussion: The ISO definition is considerably more broad than that specified in NFPA 921 and as such would be inclusive of phenomena such as ventilation induced flashover as well deflagration resulting from introduction of air to an extremely ventilation controlled fire. The definition of backdraft in NFPA 402, Guide for Aircraft Rescue and Firefighting Operations illustrates the common misconception that carbon monoxide is the primary gas phase fuel in a backdraft. There is no scientific evidence that this is the case. Both NFPA definitions indicate that backdraft is explosive in nature (e.g., deflagration) while the ISO definition indicates that this is a possibility, but not a requisite outcome.

• How does backdraft differ from a vent induced flashover? This is essentially the same question as before, but this time, think about it from the backdraft perspective.
• If there is a difference between vent induced flashover and backdraft, what is different (about the nature of the phenomena, requisite conditions, and initiating event(s))?
• Many firefighters believe that backdraft requires high temperature (resulting in auto-ignition following an increase in ventilation), yet this is not mentioned in any of the definitions. Is this the case?
• Is a backdraft always an explosive event?

Fire Gas Ignition: Ignition of accumulated unburned pyrolysis products and flammable products of incomplete combustion existing in or transported into a flammable state (Grimwood, Hartin, McDonough, & Raffel, 2005)

Discussion: In 3D Firefighting, Grimwood uses the term Fire Gas Ignition as a broad category of phenomena including smoke (fire gas) explosion, flash fire, and a number of other fire behavior phenomena.

• What differentiates phenomena classified as fire gas ignitions from backdraft, or for that matter flashover?
• If there is a common theme, is it useful to have an overarching category such as fire gas ignition?

Smoke Explosion: 1) See Backdraft (NFPA 921, 2008). 2) When unburnt gases from an under-ventilated fire flow through leakages into a closed space connected to the fire room, the gases there can mix very well with air to form a combustible gas mixture. A small spark is then enough to cause a smoke gas explosion (Karlsson & Quintiere, 2000). 3) A smoke gas explosion results from ignition of a confined mass of smoke gases and air that fall within the flammable range. This may result in a significant increase in pressure within the compartment (paraphrased from Bengtsson, 2001).

Discussion: In the past, the terms smoke explosion and backdraft were frequently used synonymously (and still used this way within NFPA 921). However, smoke explosion is a substantively different phenomenon as evidenced by the definitions provided by Karlsson & Quintiere (2000) and Bengtsson (2001). Drysdale (1998) also discusses this phenomenon, and while not providing a definition per say, delineates the difference between smoke explosion and backdraft as different phenomena.

• How are smoke explosion and backdraft different?
• What differentiates smoke explosion from flash fire?
• The phenomenon of smoke explosion as defined in various texts requires a mixture of fuel and air within the flammable range. If this flammable mixture is achieved by an increase in ventilation (adding air to a rich mixture of air and fuel), would piloted ignition result in a smoke explosion or backdraft?

Flash Fire: A fire that spreads rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitable liquid, without the production of damaging pressure (NFPA 921, 2008, 3.3.72)

Discussion: While this definition appears reasonably clear when taken by itself, how does this differ from rollover, or for that matter flashover?

• What differentiates flash fire from other phenomena such as rollover (flameover) where fire spread rapidly through gas phase fuel in the upper layer?
• While the term “flash” infers a brief occurrence, the definition does not clearly define the duration of this phenomenon. Is this different from the rapid transition to a fully developed fire that results from flashover?
• What differentiates flash fire from a smoke explosion (the NFPA definition of flash fire provides a fuzzy hint, but is this clear enough)?

For a longer and more detailed examination of the definitions of flashover and backdraft, see The Current Knowledge and Training Regarding Flashover, Backdraft, and Other Rapid Fire Progression Phenomenon (Gorbett & Hopkins, 2007).

What Next?

Over the next couple of months, I will be working to develop a discussion (in a variety of formats) to develop a common framework and working definitions that will aid us in talking about fire behavior phenomena that present a significant threat to firefighters (i.e., extreme fire behavior). I invite you to be part of this process! More information will be provided in subsequent posts.

Ed Hartin, MS, EFO, MIFireE, CFO

References

Bengtsson, L. (2001). Enclosure Fires. Karlstad, Sweden: Räddnings Verket.

Drysdale, D. (2000). An introduction to fire dynamics. Chichester, England: John Wiley & Sons.

Gorbett, G. & Hopkins, R. (2007). The Current Knowledge and Training Regarding Flashover, Backdraft, and Other Rapid Fire Progression Phenomenon. Retrieved March 19, 2009 from http://www.kennedy-fire.com/backdraft%20paper.pdf.

Grimwood, P., Hartin, E., McDonough, J., & Raffel, S. (2005). 3D firefighting: Training , techniques, and tactics. Stillwater, OK: Fire Protection Publications.

Karlsson, B. & Quintiere, J.G. (2000). Enclosure fire dynamics. Boca Raton, FL: CRC Press.

National Fire Protection Association. (2008) NFPA 402 Guide for aircraft rescue and fire-fighting operations. Quincy, MA: Author.

National Fire Protection Association. (2008) NFPA 921 Guide for fire and explosion investigations. Quincy, MA: Author.

Newbolt, H., Bailey, J., Baines, K., Boas, F., Davies, H., Enright, D., et al. (1921). Teaching of English in England.  Retrieved March 17, 2009 from http://ia340921.us.archive.org/2/items/teachingofenglis00greaiala/teachingofenglis00greaiala.pdf