Introduction to Fire Safety Management

Principles of fi re and explosion
119
➤
Boilers, internal combustion engines or oil burning 
equipment
➤
Lightning.
7.2.4 Fuel 
sources
Everything will burn if suffi cient heat and available condi-
tions allow. Clearly some items will burn more readily than 
others, for instance wood shavings or dust will burn more 
easily than a solid block of wood. These 
fuel sources
are 
generally broken down into three main groups (although 
these are sometimes subdivided).
Solids
Often referred to as carbonaceous materials (carbon 
based) these include wood, cardboard, paper, hard-
board, soft furnishings such as carpets and curtains and 
materials such as plastics, foam rubber and even metal. 
As the structure of solids is based upon tightly formed 
particles, those, such as metals (unless reactive, i.e. 
magnesium) are very diffi cult to break down and require 
substantial heat sources to be applied for a fi re to be 
initiated.
Some solids are very ‘reactive’ and may be designated 
as ‘fl ammable’ solids under UN Transport requirements; 
these will be clearly identifi able by a label/sign.
Liquids
Far more susceptible to supplying fuel for a fi re due to 
their ability to release vapour. Liquids including petrol, 
paraffi n, white spirit, thinners, varnish and paints present 
a signifi cant risk. Chemicals such as twin pack adhe-
sives, acetone and toluene also release vapours and 
these liquids due to their low 
fl ashpoint
present an even 
greater risk.
Aerosol containers contain a fl ammable liquid which 
is pressurised to a level that it becomes a gas. The 
containers present a signifi cant risk particularly if they 
come into direct contact with a heat source.
Flammable liquids are classed as:
➤
Extremely 
fl ammable.
Liquids which have a fl ashpoint lower than 0
C:
➤
Highly 
fl ammable.
Liquids which have a fl ashpoint below 21
C but which 
are not extremely fl ammable:
➤
Flammable.
Liquids which have a fl ashpoint below 55
C but which 
are not highly fl ammable.