Crying Wolf – the dangers of false alarms in fire safety

Everyone knows the story of the boy who cried wolf and who eventually wasn't believed when there really was a wolf. A badly configured or faulty fire alarm system is effectively “crying wolf” on your behalf, which can cause some serious problems.

In the industry, these are known as unwanted fire signals. There are two main problems arising from such instances, namely:

• Occupants become desensitised to the sound of the fire alarm

• Emergency services may divert essential resources away genuine emergencies 

In the first case, where a fire alarm is sounded multiple times in a building, its occupants are shown to become desensitised to the sound, assuming it is a false alarm. It may be a false alarm, but on the occasion when it is not, the reaction time is slowed and some occupants may simply choose not to evacuate at all. In terms of fire safety, this is disastrous.

In the second instance, the Fire Service may spend time and resources attending fire alarm activations in your building which are false. This could place the service under increased pressure and impact upon other alarm instances which are not false, in your area. It is important that the emergency services are called out in real emergency situations only.

There are other, non fire safety, issues that will affect the building occupiers, particularly when it has a commercial impact. Business disruption either through the removal of all staff in an office complex or the removal of all customers in a cinema or pub can have a serious affect on productivity in one case and profit in the other.

On the basis of the above, it is clear to see the importance of ensuring a fire alarm activates in a 'real' condition only.  

Maintenance - Ideally, the fire alarm system has been designed and installed with appropriate maintenance in place.  This must be the first objective.  In existing buildings, it is likely that building management will be able to have an influence over the maintenance aspect only, this is however an important function, lack of system maintenance is a commonly reported fault.

Reporting - This is a simple identification technique to identify problem areas.  For example, if false alarms frequently occur on the 3rd floor between 9.00 and 9.30am, this will give a strong indication of what activity is causing the unwanted signal.  Once this has been identified, action can be taken; this could range from prohibiting the activity to changing the local detector heads (following specialist advice).

Delayed evacuation signal - Effectively, the fire alarm system can be reconfigured so that multiple sensors are required to activate, prior to the fire alarm sounding.  It should be noted that this effectively reduces the sensitivity of the fire alarm and requires careful and specialist consideration, an enhanced level of fire detection and building management may also be required.  It must also be noted that activation of manual call points (“Break glass here” boxes) would normally initiate an immediate evacuation signal.  Also, this system allows a pre-determined delay period, allowing time to investigate the source of activation, if no further information is provided to the system, i.e. 'the all clear' is not given within the time, the alarm will sound.

A very simple but effective tool is a fire risk assessment.  The assessment should take account of the fire risks present, set against the fire detection present.  The risk assessment should also review any unwanted fire signals and be able to ascertain the reason for false activation.  It is likely that the risk assessment will recommend simple, but effective measures, such as replacement of faulty sensor heads/alteration of detector type, for example, changing a smoke detector to a heat detector.

It is clear that the reduction of false alarms is fundamental.  There are some very simple but effective measures that can be implemented to ensure that fire safety is achieved, with no unnecessary disruption to building users and without placing a burden on the emergency services.

If you would like to know more - or would like to arrange an appointment with one of our senior fire safety advisers - simply call Peter Gyere on 020 8668 8663