Page 22 - Electrical Installation in Hazardous Area

7

ln traduction

Where combustible or flammable materials are stored or processed there is,
in most circumstances, a possibility of their leaking or otherwise having the
ability to produce what may be described as an explosive atmosphere in
conjunction with the oxygen present in air. This is true for gases, vapours,
mists and dusts and, as electricity is widely used in industries and other
places where such explosive atmospheres can occur, the propensity of elec-
trical energy to create sparking or hot surfaces presents a possibility that
the explosive atmospheres may be ignited with resultant fire or explosion.
This hazard has been recognized for many decades - almost since the use
of electricity was introduced into mining and other industries - and the
precautions taken to overcome this problem date back, in their basic incep-
tion, to the turn of the twentieth century and before.
There is no way in which explosions can be totally prevented in indus-
tries where explosive atmospheres can occur as all human endeavour is
fallible but it is necessary to develop our operations to a degree where
such explosions are so rare that their risk is far outweighed by the benefits
of the processes in which they may occur. Such balance is evident in the
coalmining industry where the overall risks associated with working under-
ground, where explosions are one constituent, have been seen as justifiable
on the basis of society’s need for fuel. It is true that the risks are minimized
as far as possible but only to a level consistent with the need to win coal
and accidents still occur. It remains true, however, that the risk of these
accidents has been reduced to a level acceptable to our society and partic-
ularly those working in the industry. That is not to say that when a risk is
identified by an incident nothing is done. We always learn from these and
invariably they result in changes to our operating systems and equipment
in order to minimize the risk of a repeat. Notwithstanding all of our efforts,
however, accidents of significant proportion still occur with a degree of
regularity which causes us all concern.

1 .I Examples of historic incidents

The following are examples of the more significant incidents occurring in
the UK and, although they were not necessarily caused by electricity, there
is in at least one of the cases a suspicion of electrical initiation and electricity,
as has already been indicated, is seen as an obvious igniting agent.