Archive for July, 2015

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.<–14311>
  2. “Active Shooter Events from 2000 to 2012.” FBI. Web. 7 Dec. 2014. <>

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

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.