Selecting and Using Fire Extinguishers For Your Home

Every home should have at least one fire extinguisher, located in the kitchen. Better still is to install fire extinguishers on each level of a house and in each potentially hazardous area, including (besides the kitchen) the garage, furnace room, and workshop.
Choose fire extinguishers by their size, class, and rating. "Size" refers to the weight of the fire-fighting chemical, or charge, a fire extinguisher contains, and usually is about half the weight of the fire extinguisher itself. For ordinary residential use, extinguishers two and a half to five pounds in size usually are adequate; these weigh five to ten pounds.
"Class" refers to the types of fires an extinguisher can put out. Class A extinguishers are for use only on ordinary combustible materials such as wood, paper, and cloth. Generally, their charge consists of carbonated water, which is inexpensive and adequate for the task but quite dangerous if used against grease fires (the pressurized water can spread the burning grease) and electrical fires (the water stream and wetted surfaces can become electrified, delivering a possibly fatal shock). Class B extinguishers are for use on flammable liquids, including grease, oil, gasoline, and other chemicals. Usually their charge consists of powdered sodium bicarbonate (baking soda).
Class C extinguishers are for electrical fires. Most contain dry ammonium phosphate. Some Class C extinguishers contain halon gas, but these are no longer manufactured for residential use because of halon's adverse effect on the earth's ozone layer. Halon extinguishers are recommended for use around expensive electronic gear such as computers and televisions; the gas blankets the fire, suffocating it, and then evaporates without leaving chemical residue that can ruin the equipment. Another advantage of halon is that it expands into hard-to-reach areas and around obstructions, quenching fire in places other extinguishers cannot touch.
Many fire extinguishers contain chemicals for putting out combination fires; in fact, extinguishers classed B:C and even ARC are more widely available for home use than extinguishers designed only for individual types of fires. All-purpose ARC extinguishers usually are the best choice for any household location; however, B:C extinguishers put out grease fires more effectively (their charge of sodium bicarbonate reacts with fats and cooking oil to form a wet foam that smothers the fire) and so should be the first choice in a kitchen.
"Rating" is a measurement of a fire extinguisher's effectiveness on a given type of fire. The higher the rating, the more effective the extinguisher is against the class of fire to which the rating is assigned. Actually, the rating system is a bit more complicated: rating numbers assigned to a Class A extinguisher indicate the approximate gallons of water needed to match the extinguisher's capacity (for example, a 1A rating indicates that the extinguisher functions as well as about a gallon of water), while numbers assigned to Class B extinguishers indicate the approximate square footage of fire that can be extinguished by an average nonprofessional user. Class C extinguishers carry no ratings.
For protection on an entire floor of a house, buy a relatively large extinguisher; for example, a model rated 3A:40B:C. These weigh about ten pounds and cost around $50. In a kitchen, choose a 5B:C unit; these weigh about three pounds and cost around $15. For increased kitchen protection, it is probably better to buy two small extinguishers than a single larger model. Kitchen fires usually start small and are easily handled by a small extinguisher; smaller extinguishers are more manageable than larger ones, especially in confined spaces; and, because even a partly used extinguisher must be recharged to prepare it for further use or replaced, having multiple small extinguishers makes better economic sense.
A 5B:C extinguisher is also a good choice for protecting a garage, where grease and oil fires are most likely. For workshops, utility rooms, and similar locations, obtain IA: lOB:C extinguishers. These, too, weigh about three pounds (some weigh up to five pounds) and cost around $15. In all cases, buy only extinguishers listed by Underwriters Laboratories.
Mount fire extinguishers in plain sight on walls near doorways or other potential escape routes. Use mounting brackets made for the purpose; these attach with long screws to wall studs and allow extinguishers to be instantly removed. Instead of the plastic brackets that come with many fire extinguishers, consider the sturdier marine brackets approved by the U.S. Coast Guard. The correct mounting height for extinguishers is between four and five feet above the floor, but mount them as high as six feet if necessary to keep them out of the reach of young children. Do not keep fire extinguishers in closets or elsewhere out of sight; in an emergency they are likely to be overlooked.
Buy fire extinguishers that have pressure gauges that enable you to check the condition of the charge at a glance. Inspect the gauge once a month; have an extinguisher recharged where you bought it or through your local fire department whenever the gauge indicates it has lost pressure or after it has been used, even if only for a few seconds. Fire extinguishers that cannot be recharged or have outlasted their rated life span, which is printed on the label, must be replaced. In no case should you keep a fire extinguisher longer than ten years, regardless of the manufacturer's claims. Unfortunately, recharging a smaller extinguisher often costs nearly as much as replacing it and may not restore the extinguisher to its original condition. Wasteful as it seems, it is usually better to replace most residential fire extinguishers rather than have them recharged. To do this, discharge the extinguisher (the contents are nontoxic) into a paper or plastic bag, and then discard both the bag and the extinguisher in the trash. Aluminum extinguisher cylinders can be recycled.
Everyone in the household except young children should practice using a fire extinguisher to learn the technique in case a fire breaks out. A good way to do this is to spread a large sheet of plastic on the ground and use it as a test area (the contents of most extinguishers will kill grass and stain pavement). To operate a fire extinguisher properly, stand or kneel six to ten feet from the fire with your back to the nearest exit. (If you cannot get within six feet of a fire because of smoke or intense heat, do not try to extinguish it; evacuate the house and call the fire department.) Holding the extinguisher upright, pull the locking pin from the handle and aim the nozzle at the base of the flames. Then squeeze the handle and extinguish the fire by sweeping the nozzle from side to side to blanket the fire with retardant until the flames go out. Watch for flames to rekindle, and be prepared to spray again.
Chimney Fire Extinguishers
If you operate a fireplace or wood-burning stove, keep on hand two or three oxygen-starving sticks, available at fireplace and woodstove dealers. In case of a chimney fire, tossing the sticks into the flames will quickly quench a fire inside the chimney flue or stovepipe. Evacuate the house and call the fire department immediately in any case.