Posts Tagged ‘Fire Protection Engineering’

by: Elizabeth Keller

 

Everyone is aware of the benefits of professional licensing for Fire Protection Engineers; however, few people consider the cost (time and money) for maintaining licensure.  Although the benefits far outweigh the costs, there is an opportunity for improvement in the licensing system that would greatly streamline license maintenance.

A professional engineer must meet the engineering licensure requirements in each state in which the professional engineer seeks to practice.  Most states allow licensure by comity if a professional engineer is already licensed in another state with requirements at least equal to those in the state in which licensure is being sought.  Fire Protection Engineers are always in demand and are increasingly crossing state lines and finding the need to be licensed not just in one state, but in many.  Sounds great, doesn’t it?

The issue is that most states require continuing education prior to the renewal of an engineering license.  Continuing education requirements are not uniform across the states and unlike the more streamlined comity application process, very few recognize the requirements for continuing education via comity.  Renewal periods range from annual to triennial, and the number of continuing education hours ranges from zero to thirty-six (36) or more per renewal period.  It is up to the licensee to keep track of their continuing education hours (also called professional development hours in some states) and to present a log of activities to the licensing board upon request.

Imagine being licensed in more than ten states.  No two of your licenses expire in the same month and different requirements must be satisfied for each.  How do you balance that?  Do you fulfill the requirements of the most demanding state and know that the others are then taken care of?  Unfortunately, it’s not that simple.

Not only do different states have different hour requirements, they also have specialty requirements, such as the need for “live” training, multiple categories for activities with specific limits on each category, and requirements for state specific courses in ethics and rules and regulations.  You could complete all of the continuing education activities required for one state, and still only be halfway to completion in another state.

So why are all of the requirements different?  Well, the simple answer is that’s just the way it is.  Professional licensing boards are all made up of representatives from the state they represent.  They are empowered by the laws of their state and they research, propose, and vote on amendments to their regulations on a state board basis.  Although one state may look at another’s process, there is no real crossover.

What about NCEES you ask?  The National Council of Examiners for Engineering and Surveying (NCEES) published model Continuing Professional Competency (CPC) Guidelines in 2008 for the use of state licensure boards in developing state specific requirements for continuing education.  Many pieces of the NCEES CPC guidelines can be found in state laws and regulation across the country, but boards can pick and choose the pieces that ultimately become incorporated.  If all states used the NCEES CPC guidelines, it would even the playing field and make complying with continuing education requirements a much simpler process.

One idea that could easily streamline this process is a national licensing board for engineers.  Currently, NCEES plays a large role in the licensing of engineers for every state and every prospective engineer generally follows the same four major steps:

  1. Earn a degree from an ABET accredited engineering program.
  2. Pass the Fundamentals of Engineering (FE) exam.
  3. Gain acceptable work experience (typically a minimum of four years).
  4. Pass the Professional Engineer (PE) exam in the appropriate discipline.

What is the benefit to having each state manage application approval when a national council is really managing the application process?  Perhaps the benefit is in the details, but this is not certain.  This is a debate that has many sides and deserves more research.

Overall, the professional engineering licensure system could be well served by a reset and reboot.  As more states adopt continuing education requirements and more engineers cross state lines in the name of business, a better and better case can be made for the development of national guidelines and somewhere in the future, perhaps even a national licensure board.

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by: Nathan Pascale

 

When analyzing the effect of toxicants, there are a few trains of thought that we must consider. First, there are the biological effects. How does the human body process the harmful byproducts that are be produced during a fire and how effectively can it do so? This perspective looks exclusively from an organic point of view, only taking into account functions within the body. The second consideration is for behavioral influences. At a micro scale level, this could be linked to the biological effects as far as how the toxicants can debilitate the brain’s capacity to function normally. However, in taking a big picture point of view this can simply be defined as changes in an individual’s decision making and the actions they take as a result of the toxicants. Finally, in the grand scheme of a fire scenario, we can look at how these biological and behavioral variations can affect the overall tenability analysis of a particular building.

As mentioned previously, the main concerns when determining the tenability of the building are the time to impair one’s ability to escape in a timely manner and the time to incapacitation. The time to impair can be correlated to the behavioral consequences of toxicants in a fire. While the panic theory has been largely debunked, a normal individual is still expected to require time to perceive, recognize, respond, and move to a safe area, and this is all without the effect of toxicants. When we introduce that extra layer of complexity, the question of how much time is enough time becomes much harder to answer. There are many factors that vary on an individual basis that can affect the way they react to the problem at hand, one of them being age.

While irritant gases are important to consider in any fire scenario, their effect is very difficult to quantify due to differing opinions in the field and overall lack of data. Thus, for the sake of this argument, I will focus on narcotic gases. Unlike irritant gases, the lethal and incapacitating effects of narcotic gases are much more accessible and quantifiable through research on animal exposure as well as posthumous studies of fatal fires. Narcotic gases act primarily by attacking the nervous system and to a lesser extent the cardiovascular system. The result is a lethargic state, coupled with headache, nausea, or poor physical coordination, followed quickly by incapacitation or death once the body can no longer compensate for the lack of oxygen being supplied to the brain.

Carbon monoxide (CO) is a toxicant present as a byproduct of all fires. Many deaths have occurred due to CO inhalation where the victims are asleep or inactive for a duration of time before becoming aware of the danger. A model developed by Professor David Purser in 2008 showed that active subjects with greater respiratory minute volume (RMV) rates were much more susceptible to the effects of CO than subjects at rest. When an individual is remote from a room of origin that has undergone flashover, toxicants are inhaled while in a sedentary state until the danger is recognized. At this moment, the exposed individual tries to escape, at which point the effects of the increased respirations an environment laden with CO begin to cause severe impairment or incapacitation.

Elderly individuals are also more likely than the average adult or child to have conditions such as asthma or coronary artery disease. A study conducted by the EPA in 2000 determined that the tenability limit of carboxyhemoglobin (the amount of CO in your blood) for an individual with coronary artery disease is only 5%, while the limit for an average adult is 30% (Purser 2008) and 25% for a child (Klees 1985). Additionally, according to an SEFS report, elderly individuals are expected to spend more time in their bedroom then adults and children. The fact that elderly people are more vulnerable due to physical condition, preexisting health concerns, and that they spend more time in the bedroom environment when exposed to fire conditions, we can conclude that elderly individuals comprise the age group at the greatest risk of death and injury when faced with narcotic gases.

In conclusion, there is evidence to prove a correlation between the effects of toxicity and age, but not enough to reliably quantify what those effects are. Preexisting illnesses, physical conditions, familiarity with the building, and susceptibility to toxicants are just a few of the factors that have to be taken into account during a tenability analysis. Unfortunately, due to the harmful nature of toxicants, experimental studies on humans are considered unethical and there is not a large pool of data to analyze for effects on past fire victims. Thus, with the information currently available, the elderly population can be considered most at-risk in a toxicant exposure event, followed by children, and then adults. Consequently, it is my hope that code committees and the fire protection community as a whole takes a closer look at these factors and evaluates the possibility of increasing the required safe egress time, whether it be by decreasing the walking speed, increasing recognition time, or otherwise, for those occupancies and buildings that shelter a large number of elderly people or children.

References

Purser, D.A., “The Effects of Fire Products on Escape Capability in Primates and Human Fire Victims,” International Association for Fire Safety Science, 2008.

Klees, M., Heremans, M., and Dougan, S. “Psychological sequelae to carbon monoxide intoxication in the child,” Sci. Tot. Environ., 1985.

Gann, R.G., J.D. Averill, K.M. Butler, W.W. Jones, G.W. Mulholland, J.L. Neviaser, T.J. Ohlemiller, R.D. Peacock, P.A. Reneke, and J.R. Hall Jr., “International Study of the Sublethal Effects of Fire Smoke on Survivability and Health (SEFS): Phase I Final Report,” National Institute of Standards and Technology, August 2001.

by: Matthew Gentzel

Mass Notification by Gentzel

Having spent my first semester of college at the United States Air Force Academy, I have been exposed to a lot of mass notification during drills. In general, by using the same systems to communicate information for fire evacuations, as well as other events, organizations have the opportunity to save money, streamline reaction times, and to frequently check that their emergency systems work. On the other hand, they also face the risks of causing confusion if alarms are not paired with specific information and direction (e.g., at the Academy there were many different alarm sounds for different types of threats, but not everyone knew the difference between the tones). Despite these and other possible problems, integrated mass notification systems are likely to be very beneficial, especially when paired with voice notification.

Although technological developments and improvements have affected mass notification systems, much of their implementation has been primarily affected by historical incidents and trends:

“The motivation to expand NFPA 72 to include mass notification and emergency communications systems beyond just fire events was driven by a number of fatal events such as the Khobar Towers bombing in 1996 and the Virginia Tech massacre in 2007. The Department of Defense (DOD), through the United States Air Force, first petitioned NFPA to develop a standard on mass notification in 2003.” [1]

With increases in the trending frequency of mass shooting in the recent years [2], a corresponding increase in mass notification is likely to continue, and to be beneficial to life safety. In a recent 2014 NFPA workshop, a panelist from the Federal Bureau of Investigation (FBI) described the scope of active shooter incidents, and more specifically how they affect schools. In 14 out of 16 studied school shootings, the shooters were students, which indicates a need for mass notification systems that cannot be abused by insiders.

Similarly, a problem was discussed by the panel about the issue of having too much communication. Due to the presence of social media, there is a high likelihood that during an emergency there may be reduced phone service from the high use of personal mobile devices. To prevent this, mass notification to mobile devices should be able to instruct message recipients to only send vital messages so that first responders can communicate situation updates.

Among other data considered, there was discussion of the effectiveness of lockdowns. Lockdowns are security measures taken during emergencies to prevent people from leaving or entering an area, and often involve taking shelter in place. Mass notification provides a rapid means of implementing a lockdown policy throughout a building or area, and can harden potential targets against harm, giving emergency responders more time to react to such situations. Although the median police response time to an active shooter incident is approximately three minutes, having building occupants seek shelter before this amount of time is likely to make a significant difference. According to the FBI, “The five highest casualty events since 2000 happened despite police arriving on scene in about 3 minutes.” [2] Because most of the damage inflicted in an active shooter incident is often early on, reducing the reaction times of potential victims is likely to be one of the highest leverage areas for reducing deaths. Though pre-training methods such as the “Run, Hide, Fight” technique are likely to be most effective, mass notification may play a future role in preventing bystanders from unknowingly entering an area that they are likely to be harmed.

Another type of potential problem for mass notification in the event of direct attack is that an attacker could deliberately send false information. Emergency responders have already dealt with the problem of false alarms and potential traps for years. The new complication of having mass notification is the potential for false information to be rapidly distributed to others. Systems should be designed so attackers cannot access voice notification systems, and so that fire alarms do not give access to secure areas during a lockdown.

Despite the benefits of emergency text alert tones in instances where there is a direct attack, there is the chance that this type of notification could be abused. Since part of the point of a lockdown in an active shooter incident is to make it harder for a gunman to find targets, loud emergency tones could assist such a person in differentiating between empty and occupied rooms. Ultimately, it is up to phone service providers to create the software so alerts can be sent with or without tones.

With over 160 mass shooting incidents recorded by the FBI, there is still a great deal of analysis left to tackle this specific type of problem. Security from an attack is very expensive, so good solutions to these sorts of problems will be dependent upon risk assessment as well as cost effectiveness. Based on the threats that are the most likely and the most harmful, reasonable measures can be taken to increase the resilience of mass notification systems and to streamline their integration with fire alarm systems.

 

  1. “How NFPA 72 Defines Mass Notification.” Facilitiesnet. N.p., n.d. Web. 07 Dec. 2014.<http://www.facilitiesnet.com/firesafety/article/How-NFPA-72-Defines-Mass-Notification–14311>
  2. “Active Shooter Events from 2000 to 2012.” FBI. Web. 7 Dec. 2014. <http://leb.fbi.gov/2014/january/active-shooter-events-from-2000-to-2012>

by: Jason A. Sutula

The (cliché?) saying, “It’s not what you know, it’s who you know,” comes to mind as I write this short blog post. Mostly because I have the good fortune to know Samarra Khaja. Besides being family and a friend of mine, she is a highly talented and creative individual. While having her husband and family over for a visit recently, she spent some time working with me on a new branding image for the blog. The final result is below. If anyone who reads this blog has a need for logo & branding work, illustration, or photography (and several other creative services), I hope you will consider contacting SK. You can check out her work at smarrakhaja.com.

And now, the reveal:

Logo low res

Feel free to chime in on the design in the comment section. If there is enough interest, maybe I will make up some t-shirts and give them away in a contest!

by: Michael Harris

There are many methods that fire protection engineers can use to calculate egress time. One popular method taught is hand calculations that are based off of fluid dynamics (these can be done on a computer also). Unfortunately, this method does not take into account human behavior. There are many factors in a fire that can affect human behavior and egress time. One big factor is the toxic smoke produced by a fire.

Tadahisa Jin and Tokiyoshi Yamada (Jin and Yamada, conducted an experiment in Tokyo, Japan on the effects of human behavior in smoked filled corridors. This study attempted to produce as accurate results as possible by using 31 human subjects, aged 20 to 51, as oppose to animal subjects that previous smoke inhalation studies had used. The experiment was done in a straight corridor that was 11 m long, 2.5 m wide, and 1.2 m high. Certain stopping points were arranged in the corridor where the occupants were meant to stop and answer a simple arithmetic question. While in the corridor, the subjects were exposed to different levels of smoke and radiated heat. The inside of the corridor was also illuminated with fluorescent lamps.

To protect the subjects, a 16 layered towel was positioned on their nose and mouth. This provided a filtration of approximately 90% of the smoke from the environment. Additionally, the subjects had no prior knowledge of the corridor before, but were told it was a straight corridor with an end and that they could turn around at any point.

The study resulted in 17 of the subjects reaching the end of the corridor. Fourteen of the subjects had to turn around before reaching the end. An additional finding was that the subjects answered the arithmetic question incorrectly at a higher rate when the smoke density was higher. This correlation was almost linear. Finally, the subjects’ correct answer rate increased as they walked farther into the corridor. The experimenters concluded that this effect was due to the subjects becoming more emotionally stable as they acclimated to the controlled environment.

Jin and Yamada’s study resulted in valuable information that helped to better understand human behavior in a toxic gas environment. Close to half of the occupants decided the emotional toll was too high and decided to reverse direction and retreat out of the smoke filled corridor. It is worth noting that none of the subjects were exposed to a true fire scenario, considering that they only had to walk through a straight corridor and were protected from the toxicity of the smoke. A reasonable inference would be to assume that more of the subjects would have turned around in the corridor if they experienced pain due to breathing in the toxic smoke.

One of the most important findings of the study is that occupants will change their path due to the presence of smoke. This action of changing path can greatly increase egress time, and put the occupants at higher risk of injury or even fatality. Furthermore, the subjects’ cognitive ability decreased with heavier smoke. This decrease was strictly due to the emotional stress of the scenario. In an actual fire, occupants of the structure may lose cognitive ability to the point of not being able to find a safe path out.

The silver lining in this experiment is that the subjects’ cognitive ability was found to increase over time as they acclimated to the environmental conditions. Unfortunately, this observation may be inaccurate due to the limitations of the experiment. The possibility exists in an actual fire that the occupants will be exposed to an increasing dose of toxicants. Furthermore, in many structures, an occupant will not have as direct of an egress path as utilized in the experiment.

It is clear from the Jin and Yamada study that simply using fluid dynamics to calculate the egress time is not enough. Fortunately, many fire protection engineers will add a safety factor to help account for limitations such as human behavior. My hope is that future research will eventually give our community better insight into human behavior in fire, and allow for a more quantitative approach to the design of fire safe egress.

Jin, Tadahisa, and Tokiyoshi Yamada, “Experimental Study of Human Behavior in Smoke Filled Corridors.” Fire Safety Science-Proceedings of The Second International Symposium, pp. 511-519, 1989.

by: Jason A. Sutula

This past Friday, Sara Caton presented an excellent take on the potential electrocution risk to fire service personnel when encountering a roof-mounted solar array during an active fire event. Her post raises several good points that must be accounted for in both the training of firefighting personnel as well as understanding the interaction between a solar panel installation and the building construction elements below it.

As a follow up to her post, I received a comment from Professor James (Jim) Milke, Chair of the Department of Fire Protection Engineering at the University of Maryland. Professor Milke reminded me that Rosalie Wills led a group of students that put together a report for the Fire Protection Research Foundation (FPRF) on the hazard assessment of commercial installations of roof-mounted solar panels. The report highlighted a range of environmental exposures in addition to the more common discussion of the performance of the array when involved in fire.

Structural loading, wind loading, hail, snow, debris accumulation, seismic activity, and the hazards of fire are all addressed within the report. A common theme among many of the hazards that were assessed was the idea that the weight of the solar array is not negligible. A photovoltaic array is commonly mounted on to a typical roof assembly that was not originally designed to account for the additional loading of the array. While the roof assembly can support the loading of the array in normal conditions, wind loading, snow loading, and loading from other debris accumulation can cause stresses within the roof assembly over time.

When fire is added to the equation, the increased structural loading on the roof assembly can cause more rapid failure and collapse, especially if an interior fire exposes the roof members directly below the area where the solar array is mounted. Destruction of the supporting building construction under the solar array will cause damage to the electrical distribution system from the array to the structure leading to the development of the electrical hazards to firefighters as discussed in the previous post.

The model building codes have developed new provisions that address some of the hazards analyzed in the FPRF report. The 2012 edition of the International Building Code (IBC) requires a solar array system to have the same fire class rating as the roof assembly. Additionally, Underwriters Laboratory (UL) Standard 1703 (Standard for Flat-Plate Photovoltaic Modules and Panels) was updated with additional testing methods to be able to account for a roof mounted photovoltaic fire class assembly rating. Finally, NFPA 70, the National Electric Code (NEC), has included many provisions within the latest edition to limit the potential of an electrical failure of a photovoltaic system. Progress in the fire safety and minimization of the hazards of these systems continues to be made.

If interested in more information, take the time to watch today’s embedded YouTube video. This was created by the NFPA, and Ken Willette does a good job of pointing out the resources available for fire safe installations of photovoltaic systems.

by: Peter Raia

The fire service is a traditional, paramilitary brotherhood that is one of the most long standing professions in the world. I had the privilege of joining this brotherhood in 2007, at the age of 15. I quickly gained a large interest in firefighting and wanted to learn what goes on “behind the flame,” for a lack of a better phrase. Shortly after joining the fire service, I stumbled upon the Fire Protection Engineering Program at the University of Maryland and gained an entry level understanding of fire dynamics and computer fire modeling. Unfortunately, some of what I learned with my degree did not correspond to my knowledge of basic firefighting.

“Penciling” is a technique taught in fire academy classes as, “short blasts of water, aimed at the ceiling, to provide enough cooling to stop or slow a flashover.” I was taught that three, one second long bursts at the ceiling are enough to cool the ceiling temperatures to fight back the onset of flashover and allow the fire attack crew to push on to the seat of the fire for final extinguishment.

As a fire protection engineer, this practice did not make sense. Why would you only provide three short bursts of water at the ceiling when you have a “relatively infinite” amount of water to cool the surrounding atmosphere? And, why just at the ceiling? The ceiling only accounts for one of the sides of the room that are affected by the high temperatures of the upper smoke layer. The temperature of these surfaces can be near, and sometimes over, 1000 degrees Fahrenheit immediately before flashover. Three short shots of water at the ceiling will only decrease the temperature slightly and for a short amount of time before the upper smoke layer overwhelms the cooling and heat displacement created from the water application. In my mind, it made more sense to apply water to multiple sides of the compartment, hopefully causing a rapid decrease in the compartment temperature and the conversion of liquid water to steam.

I took this question to my fire academy instructor, who I am very friendly with and currently work alongside with as a firefighter. The response I received was not as grounded in science as I expected. My friend stated, “Pete, that amount of water would cause extreme steam burns to your body (i.e., rapid steam expansion due to the water phase change), and it is the way it has always been taught.”

I partially agreed with his first point. Steam burns are atrocious. They resemble and feel like severe sunburns, but occur all over the body in some cases. However, these burns have become rarer with improvements in protective gear standards and new and improved practices in fire ground ventilation.

His second argument was more problematic. The standard rebuttal, “because that’s the way it has always been done…,” is just not in line with modern fire dynamics and fire fighting tactics. This answer simply is not good enough to warrant the practice of a technique that is performed in as hazardous a job as fighting fire.

With the help of online resources, I began to research the direct application of a continuous water stream to the upper layer in an effort to rapidly cool and decrease the flashover temperature of the fire room. Kill the Flashover is one example of a group that is working on this type of research (NIST has also conducted research in this area). As a group of firefighters/engineers, they are dedicated to examining the ins and outs of attacking and preventing flashover. In addition to many other live fire burns, they have performed a comparison test of the penciling technique and the full-flow technique. In their experiment, Penciling demonstrated improvement in the fire compartment, but these improvements were temporary and still fostered high temperatures and dangerous operating conditions for the interior firefighting crews. The full-flow technique performed much more consistently, and in some instances resulted in the full extinguishment of the fire in the compartment.

A question to now pose to ourselves is, “do we get firefighters to use this method?” More research is certainly needed, and once completed and analyzed, the next step is to get this information out to the fire service community. In my experience on the fire ground, practice is the best form of education. The more you practice a proven technique, the more convinced you will be of its validity. In modern firefighting practice, it is imperative to question the old “because that is how it has always been done” attitude and embrace the idea of more adaptive and scientifically-based techniques.