The Federal Emergency Management Agency reports that, from 2009 to 2011, 7 percent of all residential building fires were electrical fires. Virtually all electrical fires are nonconfined, making them more dangerous and destructive, and they tend to result in more costly property damage than other types of fires.
What Is an Electrical Fire?
FEMA defines an electrical fire as one caused by heat from electrical transformers, meter boxes, outlets, cords, light bulbs and anything else that conducts electricity. Common sources of ignition include arcing caused by power surges and frayed wire insulation that allows contact between flammable materials and hot electrical conductors. These fires start most often in bedrooms and attics, and the most common ignitable material that starts the fire is the wire insulation itself, although framing members, wall insulation and wall coverings also ignite.
Don't Use Water
The No. 1 piece of safety advice -- as far as electrical fires are concerned -- is to avoid trying to put one out with water. Water conducts electricity, and you could be seriously shocked or electrocuted if the water extends in a continuous stream from the fire to your hands. Not only that, instead of putting out the fire, water may simply help it spread by conducting the electricity throughout the room, where arcing and sparks could ignite flammable materials.
Do Use a Type C Fire Extinguisher
Electrical fires are class C fires, and your house should be equipped with a type C fire extinguisher to combat small fires. This type of fire extinguisher puts out a fire by smothering it with carbon dioxide, thus depriving it of the oxygen it needs for combustion, or by discharging a dry chemical. Unlike water, the discharge from the fire extinguisher won't conduct electricity.
In addition, you can use a multi-purpose ABC fire extinguisher, which is also suitable for other types of fires. It typically contains dry chemicals. Both class C and ABC extinguishers are clearly labeled.
Appliance, Heater and Computer Fires
Appliances can overheat and cause fires -- often because of poor grounding, power surges or motor friction -- and the heating elements on electric space heaters can overheat -- usually because dirt has collected on them. Moreover, the logic boards inside computers can overheat and ignite, often because of a power surge. Until you unplug the appliance, heater or computer, it's a class C fire and requires a type C fire extinguisher. Once you unplug the device, you can use other means to extinguish the fire, including using another type of fire extinguisher or smothering the fire with a blanket.
Recognize When to Give Up
Electrical fires spread quickly, and once a fire is burning out of control, it may block your escape before you have a chance to react. To avoid this scenario, stop trying to extinguish the fire as soon as you see that it's spreading, despite your efforts to contain it. While there is no rule to determine this critical point, be alert to the presence of smoke coming from unseen places -- such as behind the walls -- and open flames around gas pipes or highly flammable materials, such as curtains.