Geoscience Reference
In-Depth Information
Caution:
If the light on your smoke detector blinks slowly, or it beeps at you intermittently,
that probably means that its batteries are running low and need changing.
Fire Extinguishers
A portable fire extinguisher can save lives and property by putting out a small fire or contain-
ing it until the fire department arrives; but portable extinguishers have limitations. Because a
fire can grow and spread quite rapidly, the number-one priority for residents is to get out safely.
Fire extinguishers have a rating label that tells you what types of fires they are designed to
work on, as well as their relative fire-fighting capacity. A class “A” fire extinguisher is de-
signed to work on standard fires such as wood, paper, textiles, etc. A class “B” fire extinguisher
is designed to work on flammable liquids such as grease, gasoline, and oil fires. A class “C”
fire extinguisher is designed to work on electrical fires. For home usage, it is recommended
that you select a multi-class fire extinguisher, such as an ABC-type extinguisher capable of
fighting a normal fire as well as grease and electrical fires (NFPA 2001).
The numbers on the fire extinguisher label also indicate relative size of the fire extinguish-
er. On a multi-class-rated fire extinguisher, the number immediately preceding the “A” is the
equivalent number of water units (a unit is 1.25 gallons) of fire-fighting capacity that are con-
tained inside the fire extinguisher. The number before the “B” is the number of square feet of
grease fire that the extinguisher is sized to fight. For example, a fire extinguisher with a
3-A:40-B:C UL rating has a rated firefighting capacity equivalent to 3 × 1.25 = 3.75 gallons of
water for standard fires, 40 square feet of grease fire fighting capacity, and is also rated to
handle electrical fires.
