As
an illustrative example, consider the potential consequence if a tool
is dropped and strikes the blade or propeller of an exhaust /
ventilation fan in use. With in a non-hazardous atmosphere, the risk
for an explosion is minimal. However, if the same tool strikes the
exposed, steel surfaces of a fan operating in a hazardous location
containing gasoline fumes, the results could be drastically different.
The blow produced by the tool could create a random spark. In the case
of gasoline fumes, the addition of a proper air and gasoline fume
mixture could result in an explosion. Minimizing this potential for a
spark ignition is also an important reason to use spark proof tools and
related equipment in hazardous locations. By incorporating basic spark
proof blade / motor construction, the potential for a spark-ignited
explosion caused by a direct blow is greatly minimized. The use of an
explosion proof motor alone, or an aluminum blade / propeller, does not
qualify the fan as "explosive proof". IMPORTANT! No air exhaust /
ventilation fan is totally explosion proof. Only a product utilizing
proper design and certification standards can minimize the risk of an
explosion in an applicable hazardous atmosphere.