Safety in Engineering
Fire and Safety
Introduction
There were 14,561 fires reported in Minnesota in
2010.
• 39 civilian deaths
• 137 reported civilian injuries
• $152 million in property damage
Extinguishing a Fire
o Extinguishing a Fire: a fire can be extinguished by removing
any one of the three elements. In practical fire-fighting terms,
this translates as starvation, cooling, smothering, and
interference:
• Starvation is the process of depriving the fire of fuel, i.e. combustible
materials.
• Cooling is depriving the fire of heat, e.g. by applying a substance such
as water that will absorb heat from the fire and reduce the temperature
below the critical level needed to sustain the fire.
• Smothering is the process of depriving the fire of the oxygen needed
to sustain the combustion process.
Multi-Class Ratings
Many extinguishers available today can be used on different types
of fires and will be labeled with more than one designator, e.g. A-B,
B-C, or A-B-C.
This label shows that this extinguisher
can be used on ordinary combustibles
(A) or flammable liquids (B). The
red slash through the last symbol
tells you that the extinguisher cannot
be used on electrical fires (C).
Be advised that most fire
extinguishers will function for
less than 40 seconds.
New Style of Labeling
Old Style of Labeling
Portable Fire Extinguishers
LIMITED IN:
• Capacity - 1.5 to 25 lbs. of
extinguishing agent
• Range - Typically 3 to 15 feet
• Duration - Discharge their
contents in only 5 to 30 seconds!
Portable Fire Extinguisher Safety
• How to use of Fire Extinguisher
• The P.A.S.S. Method
• It is easy to remember how to use a fire extinguisher if
you can remember the acronym PASS, which stands for
Pull, Aim, Squeeze, and Sweep.
• Pull the Pin.
This will allow you to operate the extinguisher.
Portable Fire Extinguisher
• The P.A.S.S. Method Cont.
• Aim at the base of the fire.
Point the extinguisher nozzle (or hose) at the base of
the fire.
• Squeeze the lever above the handle.
This
discharges the extinguisher agent. Releasing the lever
will stop the discharge.
Portable Fire Extinguisher Safety
• The P.A.S.S. Method Cont.
• Sweep from side to side.
Moving carefully toward the fire, keep the
extinguisher aimed at the base of the fire and
sweep back and forth until the flames appear to be
out. Watch the fire area. If the fire re-ignites,
repeat the process.
Fire Extinguishers Inspection