Civil Engineering Reference
In-Depth Information
10.1.3 Characteristics of people infl uencing safe
evacuation
that the full range of senses is available to the full range
of occupants of a building. Most fi re warning systems
rely on an audible warning to initiate evacuation. Once
evacuation has been initiated, most exit routes are indi-
cated by visual signs (e.g. a pictograph of a fi re exit) and
instructions (e.g. push bar to open).
It follows that a sensory disabled person may have
diffi culties not only in perceiving the risk associated with
a fi re in a building but may not hear the audible evacu-
ation warning or be able to recognise the way out. It is
therefore essential to identify the special needs of any
disabled employees when planning your fi re safety
arrangements and evacuation procedures, for example
those with sensory impairments:
How the occupants of a building may react during both
the pre-movement and travel time phases of evacu-
ation are infl uenced by the characteristics of the peo-
ple involved. When designing the means of escape from
a building it is vital to take into account the number of
occupants in a building, together with their density and
distribution throughout the building.
However, in addition to these 'occupancy factors'
there are a number of other important aspects that
infl uence people's behavior at the time of a fi re emergency
in a building, which must be considered when developing
and managing an emergency evacuation procedure,
including:
➤
People with hearing impairment may not have a
clear perception of some types of conventional
(audible) warning signals
➤
Sensory condition
➤
Physical condition
➤
➤
People with visual impairment may require assist-
ance with moving away from affected areas and
locating the designated place of safety.
State of conciseness
➤
Initial reactions
➤
Stakeholding
➤
Fire and/or heat in the building
It is also worthy of note that recent surveys suggest that
fewer than 10% of those people suffering with visual
impairment can read Braille.
➤
Building design features.
Sensory condition
When considering the development and management of
emergency evacuation procedures it is often assumed
Physical condition
Evacuation studies have been carried out which sug-
gest a general guide to the number of people who might
require special assistance in an evacuation. Studies
have concluded that, on average, some 3% of people in
such buildings cannot or should not evacuate using mul-
tiple fl ights of stairs. Similarly it should be assumed that
3% of the members of a large public crowd may require
Figure 10.6
Sign for people with hearing impairment
Figure 10.5
Buildings should be designed to facilitate
human understanding of their role and function
Figure 10.7
Sign for people with visual impairment
