Dakota State University -- NDSU Agriculture
7 Morrill Hall, Fargo ND, 58105-5655, Tel: 701-231-7881, Fax: 701-231-7044
October 23, 2003
Fire Extinguishers For Home and Farm
Little is more devastating than a fire in your home or your place of business, according to George Maher, a safety specialist with the North Dakota State University Extension Service. "Fire destroys what you have and leaves very little behind that is of any value."
Three items need to be present if a fire is to exist: fuel, oxygen, and heat. If any of the three is removed from the situation, there will be no more fire.
There are four classes of fire, based on what fuels them. Fires are classified as to type because the type of fuel dictates what you can safely use to fight the fire.
Class A fires are those that involve dry solid combustibles such as paper, wood or cloth. Most house fires are Class A until the fire burns its way to other sources of fuel. A Class A extinguisher cools burning materials below the temperature required for ignition.
When a fire is fueled by petroleum or oil based products such as gasoline, diesel fuel, oil, cooking oil, or grease, are Class B fires. These fires are difficult to extinguish with water because the fire tends to float away and spread quickly because oil products float on water. A Class B fire extinguisher will smother the fire and suffocate it by shutting off the oxygen needed for combustion.
A fire that is of an electrical nature is a Class C fire. This kind of fire involves an electrical motor, electric switches, controllers, lights, appliances, or even electronic items such as a television set, CD or DVD player. Fires involving electricity require a Class C extinguisher, which is not water based. Squirting water on a fire in a burning television set or on an electric range can be deadly.
Fires involving flammable metals, such as magnesium, sodium, potassium, or titanium must be extinguished with a Class D extinguisher. A pail of dry sand will also work. These fires are extremely hot and must be deprived of oxygen.
"Fire departments almost always urge you to get out of the house first, then call 9-1-1 for help," Maher says. "You can use a hand-held extinguisher first if you are immediately on the scene when the fire first starts."
Most fires occurring in the home or on the farm can be put out with a Class ABC extinguisher if the fire is caught early enough and the extinguisher is big enough. Extinguishers are sized by their weight in pounds. A 2 1/2-pound ABC fire extinguisher will provide about 15 to 20 seconds of fire fighting ability. A 5-pound extinguisher will last about 30 to 40 seconds. Thatís not very long, so it pays to have a large enough extinguisher and the knowledge of how to use it effectively, Maher says. "A two and one half pound extinguisher can be adequate for a specific area such as the kitchen, while a five-pound extinguisher is recommended for general home use.
Tractors and combines should be equipped with at least as 10-pound extinguisher. Farm buildings should be protected with a 20 or 25-pound extinguisher. Calling the fire department first and fighting the fire second applies to the farm also, unless you are on the scene as the fire ignites," Maher says "Rural, volunteer fire fighters rarely object to hearing that the fire is out while they are on their way to it."
PASS is the acronym for how to use a fire extinguisher; Pull, Aim, Squeeze, and Sweep.
"Never walk onto material that was burning, because it could possibly re-ignite behind you, surrounding and trapping you in the fire," Maher says. Do not expect the extinguisher to last a long time and be prepared to back out of the situation if it gets out of hand. Always have an escape route in mind and constantly re-evaluate it as you fight the fire."
Stop, Drop, and Roll is the procedure to use if your clothing should catch fire. This is extremely difficult to do since the natural, human thing to do is to run from the fire.
Some synthetic fabrics will be more difficult to stop from burning, but Stop, Drop, and Roll is still the most effective way to put out the fire, other than totally immersion in water.
Fire extinguishers should be checked periodically. Dry chemical extinguishers are filled with a powder that will "set up" with time and are ineffective when needed. These extinguishers should be checked every month and tipped and rocked back and forth to keep the powder loose and flowing.
"All fire extinguishers require checking for fire-readiness at least once a year, Maher says. "When did you check yours last? Is it fire-ready? Will it fight your fire? Check it!"