Delayed threat recognition may seem inexplicable, but it does occur and must be considered in fire protection design. If a fire alarm sounds with no apparent signs of fire, evacuation from the building takes considerably longer than if flames and smoke are clearly visible. Based on an individual's perception of what is happening, various reactions can be seen. From taking no action at all, ignoring cues, or freezing, to deciding to fight the fire, all the way to evacuating. Installing methods of fire detection and alarm signals combined with training of such systems are ways of ensuring people perceive the danger and react in time. Frequent false alarms can cause a negative reaction to future ones and could be one of the main reasons why no action is taken once an alarm sounds. Response to Different Forms of Audible and Visual Warnings Fire alarm devices can be divided into two types of warning systems:
• Audible warning devices, bells electronic sounders, etc. • Visual warning, flashing beacons, strobe lights, etc.
Both types in combination generate a greater or earlier response. It has been observed on numerous occasions that building occupants are slow in responding to fire alarm signals. Research has shown that in some buildings, occupants tend to continue their activities and completely ignore the evacuation alarm. It is important to realise that the people in the building might not recognise a fire alarm or respond to it, a fire drill can be useful to determine how people would respond to the devices in place. "Research findings show that a fire alarm signal by itself is usually not sufficient enough to initiate occupants to evacuate from buildings". The problem of recognising the fire alarm for what it is, is fundamental to the fact that people fail to respond. In no way is it suggested that fire alarms should not be used just because some occupants tend not to respond to them. Although poor response to fire alarms is not what is intended, the warning device is still a good means of alerting the building occupants. Recognition and Reaction Problems with Sensory Impairment Visually Impaired : Many visually impaired people rely almost exclusively on proximal (near) perception and have little knowledge of distant events. As such, they may be unable to read directional or exit signs that may be critical for their safe escape from a building. Therefore, emergency procedures for the safe evacuation need to be drawn up to ensure the visually impaired persons safety in an emergency. Persons with a visual impairment may be guided on level surfaces by taking someone's arm and following. On stairways the guide should descend first and the person following can than place their hand on the guide's shoulder. If a member of staff or student is a guide dog user, they should be asked about how or if they can be assisted.
©SHEilds – All rights reserved FCV 4 JUN 2021
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