A Quick Guide to Fire Extinguishers

We should all have them in our homes, but how much do we really know about fire extinguishers? First of all, please remember that fire extinguishers are meant for small fires, and no matter the size of the fire, your first steps should be to evacuate the home and call the fire department.

What Kind Do You Need?
There are five basic classes of fire. Extinguishers are rated as to the type of fire that they can put out. Some extinguishers can be used on multiple types of fires, and are designated as such on the label. It is important to be aware of the fact that using the wrong kind of extinguisher on a fire could make the fire worse, possibly causing you to be injured.

Class A: Fires in ordinary combustibles, such as wood and paper. The numerical rating for class A extinguishers refers to the amount of water the canister holds and the amount of fire it will put out.

Class B: Fires involving flammable liquids, such as grease, gasoline, oil, etc. The numerical rating associated with this class of fire extinguisher states the approximate number of square feet of a flammable liquid fire that a non-expert person can expect to extinguish.

Class C: Fires in live electrical equipment. This class of extinguisher does not have a numerical rating. The presence of the letter "C" indicates that the extinguishing agent is non-conductive.

Class D: Fires involving combustible metals. These extinguishers are often specific for the type of metal in question. These extinguishers generally have no rating nor are they given a multi-purpose rating for use on other types of fires.

Class K: Fires involving cooking equipment using grease and oil. These fires are a special hazard, and are best fought with a dry chemical such as sodium bicarbonate or potassium bicarbonate.

In addition, there are four types of extinguisher contents to choose from:

Dry Chemical: Usually rated for multiple purpose use, these extinguishers contain an extinguishing agent and use a compressed, non-flammable gas as a propellant.

Halon: Containing a gas that interrupts the chemical reaction that takes place when fuels burn, these extinguishers are often used to protect valuable electrical equipment since they leave no residue to clean up. Halon extinguishers have a limited range of about 4 to 6 feet, and the initial application should be made at the base of the fire, even after the flames have been extinguished.

Water: These extinguishers contain water and compressed gas and should only be used on Class A (ordinary combustibles) fires.

Carbon Dioxide (CO2): These extinguishers are most effective on Class B and C (liquids and electrical) fires. Since the gas disperses quickly, these extinguishers are only effective from 3 to 8 feet. The carbon dioxide is stored as a compressed liquid in the extinguisher; as it expands, it cools the surrounding air. The cooling will often cause ice to form around the "horn" where the gas is expelled from the extinguisher. Since the fire could re-ignite, continue to apply the agent even after the fire appears to be out.

How do you use them?
Using a fire extinguisher is relatively easy, since most models work in the same way.

1. Pull the pin at the top of the extinguisher that keeps the handle from being accidentally pressed.
2. Aim the nozzle toward the base of the fire.
3. Stand approximately 8 feet away from the fire and squeeze the handle to discharge the extinguisher. If you release the handle, the discharge will stop.
4. Sweep the nozzle back and forth at the base of the fire. After the fire seems to be out, watch it carefully since it may re-ignite.
5. Remember P.A.S.S.- Pull, Aim, Squeeze, Sweep!

How many do you need, and where should you put them?
The International Association of Fire Chiefs recommends that you have a fire extinguisher in the kitchen, in the garage, and on each level of your home. In addition, you should also have a smoke detector installed on every level of your home, along with an additional unit near the bedrooms for extra safety.

The extinguisher should be mounted on the wall 3-1/2 to 5 feet above the floor. The location should be near an exit or escape route from the room. It is important to remember to never travel past a fire to reach an extinguisher. You may become trapped if the fire grows rapidly.

What about maintenance?
Your extinguisher should be inspected at installation, and at least once a month thereafter. Make sure that access to the extinguisher is never blocked and that there is no evidence of corrosion or physical damage.

Maintenance and servicing should be performed by fire extinguisher servicing companies that have the proper tools and recharge materials, lubricants, manufacturer's servicing instructions and replacement parts.