In fire situations, it is not unusual for occupants to delay notifying the fire department while they attempt to fight the fire. Over the years, this has happened far too often. And, every time this kind of incident occurs, it reinforces the real impact that time has on the successful management of a fire.

On many occasions, trained occupants have used portable fire extinguishers to keep small fires from becoming large fires. But, to use portable extinguishers properly, individuals must receive proper training. This training should emphasize that the occupants must sound the alarm and notify the fire department before they attempt to fight a fire.


However, even with the proper training, it is still possible that someone will first reach for a portable fire extinguisher and forget to sound an alarm or forget to notify the fire department before trying to extinguish the fire. Another possible scenario is that someone inadvertently blocks access to the portable fire extinguisher. Similarly, a trained individual may attempt to use a fire extinguisher that isn't pressurized or is missing.


Fortunately, building owners can employ modern technology to bridge the gap between what they expect to happen when someone discovers a fire and what actually happens. Active monitoring systems are available for portable fire extinguishers. This new extinguisher monitoring system connects to the building fire alarm system or to any other centralized monitoring equipment. Whenever someone lifts a portable fire extinguisher, the interface module will initiate either a fire alarm signal or a supervisory signal on the fire alarm system. The type of signal will depend upon the building fire plan that the owner has developed and on the requirements of the authority having jurisdiction.


If someone blocks access to a portable fire extinguisher, the interface module can detect the blockage and, after a suitable and selectable time delay, initiate a supervisory signal on the building fire alarm system. This will notify management of the facility that something has blocked access to an extinguisher.

In addition, the extinguisher monitoring system will monitor the stored pressure inside the portable fire extinguisher and initiate a supervisory signal on the building fire alarm system to notify maintenance personnel that the extinguisher needs service.


The basic system and its interface module monitor the pressure gauge signals and contain the obstruction detection technology. The interface module with the specially enabled extinguisher allows a portable fire extinguisher to become a fully supervised component of a monitored fire alarm system. The system is listed and meets the requirements of NFPA 101 and NFPA 72.2 Its use also eliminates 11 of the monthly visual inspections required by NFPA 10.


The extinguisher monitoring system offers many benefits. But just the benefit of interfacing with the building fire alarm system to monitor the portable fire extinguisher can improve the overall effectiveness of the fire protection for a building.


This aspect of the integration allows the occupants to receive training so they will understand that they can have confidence that, when they lift the extinguisher off of the holder to attempt fire suppression and control, others will receive immediate notification of the situation. They will also be assured that the extinguisher is charged and ready to use.

The point behind the value of the extinguisher monitoring system rests with an understanding of the critical importance of time to truly effective fire protection. The common thread to every successful or unsuccessful outcome of a fire suppression effort relates to time. Time represents the yardstick of fire suppression.3


The times associated with a fire scenario include detection time, occupant response time, escape time, fire department response time, fire suppression set-up time and suppression time. A typical fire safety goal is to reduce all response-related times and increase the amount of time for escape. Where response times are reduced, the outcomes are more likely to be favorable, whether in terms of loss of life or reduction of the property loss.


In many new buildings constructed over the last 10 to 15 years, there will be an automatic fire sprinkler system monitored by a fire alarm system, which is connected to an off-site monitoring station. There may also be fire extinguishing or suppression systems that protect hazards unique to the occupancy of the building. In addition, portable fire extinguishers may be used to enable occupants to take action prior to the fire becoming large enough to operate one of the fixed fire protection systems.


Portable fire extinguishers can play an important part in allowing the occupants of a building to control or extinguish a fire. However, occupants can also misjudge the ability of a portable fire extinguisher to extinguish a fire. This, in turn, can introduce a delay in notifying the fire department and affect the response time.


When a person sees a fire, he or she may either choose to evacuate or choose to fight the fire.4 The ideal response for a person who discovers a relatively small fire and decides to fight that fire is to sound the alarm and grab a readily available portable fire extinguisher and attempt to extinguish the fire, or at least try to contain the fire for a short period of time. It is imperative to ensure that the extinguisher is operational and accessible.


Sadly, in some instances, people who have not received proper training will attempt to fight a fire with an extinguisher. Even worse, a trained person may "forget" the training when faced with the crisis of a real fire. In both cases, the individual will begin to fight the fire but fail to operate a manual fire alarm box to allow the fire alarm system to notify the other building occupants and the fire department.


When a person chooses to fight the fire before notifying the other building occupants and the fire department, he or she not only delays notification to the occupants and the fire department, he or she increases the danger to the other occupants of the building and delays the response of the fire department. If his or her efforts to fight the fire fail, emergency responders will not immediately respond to the fire because they have not received proper notification.


Using the extinguisher monitoring system allows system designers to integrate the use of portable fire extinguishers as part of the alarm notification process. This will reduce the response time of the fire department and reduce the "detection" time.


In addition to using this technology to reduce response time and increase escape time, the extinguisher monitoring system provides active monitoring of the extinguisher. This ensures that the portable fire extinguisher remains present and accessible, as well as properly charged and ready for use.


The gauge portion of the extinguisher monitoring system provides an active pressure gauge. This pressure gauge offers a visual pressure status, an electronic output for signaling when someone removes a fire extinguisher from its designated location, and an electronic output to signal when the fire extinguisher pressure falls below a safe operating level. The gauge's pressure monitoring circuitry utilizes a magnet on the underside of the indicating pointer that trips a switch as the internal pressure falls. The gauge's electronic signal actuates circuitry within the accompanying interface module. The interface module in turn provides an output for direct interface with most types of fire alarm systems.


The interface module also provides the base for the obstruction detection technology. The obstruction detection circuit senses when something continuously blocks access to the fire extinguisher. The interface module also manages the power circuitry and provides a trouble signal when the input power falls below a safe operating level.


Wayne Moore is with Hughes Associates, Inc.



  1. NFPA 10, Standard for Portable Fire Extinguishers, National Fire Protection Association, Quincy, MA, 2007.
  2. NFPA 72, National Fire Alarm and Signaling Code, National Fire Protection Association, Quincy, MA, 2010.
  3. Wilson, R., Time: The Yardstick of Fire Control,'' NFPA Firemen, 1962.
  4. Engineering Guide Human Behavior in Fire, Society of Fire Protection Engineers, Bethesda, MD, 2003.