Introduction to Fire Safety Management

Introduction to Fire Safety Management
Figure 8.3 A typical thermostatically controlled food
servery
it is not intended to recover the aspects here; however,
failing thermocouples and other heat controlling devices
can also cause fi res. These generally occur due to a
fault and a lack of preventive maintenance and testing,
for example using portable electrical appliance testing
known as PAT testing. This PAT testing only checks the
safety from ‘electrocution risk’ and it is possible that a
damaged heat controlling device will not be identifi ed by
such testing.
The failure of the heat controlling device is then
likely to allow the overheating of the food or substance
being cooked which may combust and catch fi re. In
instances where oil is being used to cook food, chips,
for example, this raising of the oil’s temperature releases
suffi cient vapours to cause the oil to reach its fl ash and
then fi re point.
Gas cooking systems incorporate both an ignition
source, by way of a pilot light, and a substantial fuel
source, by way of the gas supply used in the cooking
process. A number of fi res are caused each year from
faulty systems where the pilot light fails and gas is released
to mix with the air until an explosive concentration is
reached and any alternative ignition sources such as a light
switch are capable of causing an explosion or fi re.
Regardless of the type of cooking device used, if
left unattended an overheated cooking receptacle and/
or food that is allowed to burn dry will produce suffi cient
heat for a fi re to start.
8.1.3 Naked lights and fl ames
By their nature lighting units emit heat; the amount of heat
will generally depend upon two factors, the wattage or
energy consumption and the type of light, such as halogen
lamps, incandescent units or fl uorescent strip lighting.
138
As in the case of all fi res, the lights themselves will
need to be positioned close to or touching a combustible
material, or in the case of fl ammable mixtures in air,
provide suffi cient heat or an ignition source to ignite the
vapours.
Halogen lighting (high heat output) is becoming
more popular within industry and it used to light both
internal and external signage. If the signage itself is
combustible and the halogen unit has been installed
incorrectly or poorly maintained the lighting unit may
come into contact with the signage starting a fi re.
Halogen desk lamps are also in evidence in offi ces
and workshops to provide additional task lighting. These
units if poorly positioned and left unattended have the
ability to start a fi re.
As in the case of all electrical systems lighting
systems have the ability if poorly maintained or incorrectly
installed to provide an ignition source for any available
combustible material.
The inappropriate use of lighting units such as in the
case of inspection lamps used in vehicle workshops is
also known to be a cause of fi res in the mechanical and
engineering sectors of industry.
Naked fl ames are a constant source of ignition
within industry. The fl ame generating devices such as
gas torches, welding units and cutting equipment (oxyacetylene)
account for a number of fi res throughout
industry each year. Fires starting from the use of these
pieces of equipment are generally caused by human
error when using them in close proximity to other
combustible or fl ammable materials, poorly maintained
equipment or in appropriate use. These issues will be
discussed later in section 8.2.
8.1.4 Heaters and heating systems
Fires caused by heaters and heating systems can be
divided into two key areas; those that are caused by
faulty systems including poor design, inappropriate installation
or lack of planned preventive maintenance; and
those that are caused by inappropriate use or misuse.
Poor design and installation can allow the heat
produced from the system to come into direct contact
with combustible materials, perhaps such as wall
linings through which the system’s ducting is routed. As
previously discussed with regard to cooking equipment,
a lack of maintenance may allow heat controlling devices
to malfunction. In addition if moving or rotating parts are
included in a heating system any bearings may run dry
or seals fail due to a lack of maintenance.
Inappropriate positioning of combustible or fl ammable
items in close proximity to heaters and parts of
heating systems may prevent air circulation, causing a
heat build-up, or if these materials are in direct contact
or within range of any radiated heat a fi re may start.