In 2003, United States fire departments responded to 2,189,500 false alarms, excluding good intent and smoke scare calls.
Everyday throughout the United States, fire departments respond to numerous fire alarm activations. Automatically, most firefighters react with a sense of frustration when these alarms occur. Terms such as "Automatic False Alarm", "Great, another bicycle run", and "@#%^*, another fire alarm" are often used to describe the frustration.
In 2003, United States fire departments responded to 2,189,500 false alarms, excluding good intent and smoke scare calls. Thirty-six percent of the false calls were due to system malfunctions, 35 percent of the false calls were unintentional calls, including incidents in which smoke alarms operated as designed, but the operation was unwelcome and unneeded such as activations while broiling, according to the National Fire Protection Association (NFPA).
Fire department responses are often reduced to single engine responses to occupancies with multiple alarms occurring within a shift or a specific time period. Recurring responses for fire companies often lead to complacency and apathy when responding to the occupancy. Firefighters often neglect to don personal protective equipment (PPE) and upon arrival, neglect to bring standpipe hose kits and other essential tools. These conditions can lead to firefighter injuries, deaths and additional fire losses due to the extended time between arrival and the initiation of fire suppression operations.
To combat these problems NFPA and the Fire Codes require fire alarm systems to have routine maintenance and service. NFPA 72, Chapter 10 outlines inspection, test and maintenance intervals for fire alarm components, initiation devices and notification appliances. Frequencies for the visual inspection and testing of the above devices are listed in Table 10.3.1 and include requirements for weekly, monthly, quarterly, semi-annual and annual testing. Chapter 9 of the International Fire Code requires fire alarm systems to be inspected and maintained in accordance with NFPA 72. Even with proper maintenance, nuisance alarms still occur at occupancies protected by fire alarms.
After the cause for the alarm has been thoroughly investigated and the alarm has been determined to be a false activation, the company officer must identify the individual, device, system, situation or environmental condition creating the problem. In cases of intentional alarms, those persons responsible for the activation should be identified, removed from the premises, fined and/or prosecuted.
In cases of accidental activation, the problem creating the alarm should be identified. Problems can range from major issues such as circuit board failure due to a short-circuit, wear and tear, sprinkler water flow or lightening strikes; to minor problems such as steam, moisture, dust, cobwebs or insect nests in-front of or inside a detector. Obstructions, sunlight or light reflections can often affect beam type smoke detectors or infrared detection devices creating false activations.
Major problems will require the company officer to require the occupancy to initiate a "fire watch" as required by the fire code. Fire codes also place requirements for fire alarm systems and/or sprinkler systems to be repaired by personnel trained and qualified to repair those systems.
Smoke Detector Activations
In cases of minor fire alarm problems, simple solutions are often available to the company officer to either correct or reduce any further alarms. Photoelectric smoke detectors operate on light being projected from a sending unit to a receiving unit. Ionization type smoke detectors operate by a "magnetic" field being generated inside the detection chamber of the device. Any obstruction of the light or field will create false activations.