Fire extinguishers are a must for any home. Unfortunately, the contents of fire extinguishers expire after a few years whether the extinguisher has been used or not. Those contents can also be toxic and must be disposed of properly.
Fire Extinguisher Basics
There are several types of fire extinguishers. The most common type is the dry chemical extinguisher. This type sprays the fire with chemicals, which deprive the fire of oxygen and puts it out. This is the type found in most kitchens. Most dry chemical extinguishers are labeled A-B-C, which means that they are for use on general materials (everything from wood to plastic to fabric), chemical fires, and electrical fires.
Another type of extinguisher, and one which is becoming more common, is the carbon dioxide extinguisher. Since fires require oxygen to burn and grow, replacing the air around a fire with carbon dioxide "starves" the fire and causes it to go out. Carbon dioxide extinguishers are used in areas where the chemicals of a dry chemical extinguisher could cause damage, such as offices and stores where there are numerous computers.
A third type is the foam extinguisher, which is used primarily on chemical fires that would not respond to the dry chemicals or carbon dioxide. Carbon dioxide extinguishers are usually labeled B-C (chemical and electrical) fires.
A third type of extinguisher, not commonly found in offices and homes, is available for "D" fires, which are fires of flammable metals. This type of extinguisher generally contains finely powdered sand or metal and is used to smother a fire that might not react to other types of fire extinguishers.
All fire extinguishers depend on a propellant to push their contents out of the hose and onto the fire. Much like a can of whipped cream will go "flat", it is the propellant in extinguishers that tends to expire.
Recharging and Disposing of Extinguishers
Depending on the facilities in your community, you can often have expired fire extinguishers recharged for a low fee. Check your extinguisher to make sure that it can be recharged--some extinguishers are single use only--and then call the office number for your local fire department. If the fire department does not have the facilities to recharge your extinguisher, they will be able to direct you to a local business that can provide this service.
If your extinguisher is a single use model, you must dispose of it properly. This means you cannot put it in your household trash or drop it in a local dumpster. The materials that fire extinguishers are made of, combined with the chemicals inside, qualify old extinguishers as hazardous waste. To dispose of an old or empty extinguisher, put in a call to your area Public Works department or sanitation services. They will be able to instruct you as to where to take your extinguisher or where and when you can place it for pickup by the department.