Fire extinguishers are not substitute for a fire alarm system, and should only be used in conjunction with good detection equipment. They are an affordable way to put out small fires before they get out of control, and they can come in handy in the event of an emergency like a power outage. You should have at least one fire extinguisher in your home and several in your office, especially if you work with lots of electrical or other potentially dangerous equipment. There are several different types of fires and extinguishers. Most people recognize the familiar red design and assume that they are all the same, but that is not the case. A class A fire composed of combustible materials including wood, paper, plastics, and cardboard. These are the kinds that usually occur in people's homes. Class B fires are made for flammable liquids such as kerosene, oil, grease, and gasoline. These may break out in homes and businesses alike because most people have greases, oils, and gases in their homes and garages. Obviously, restaurants and gas stations experience these kinds of fire. Class C fires are electrical in nature and stem from appliances, circuit breakers, power outlets, and wires. Finally, Class D fires are started by combustible metals. These are commonly found in chemical labs, though they are not in most private residences. Class A extinguishers are watered based and should never be used on grease, electrical, and chemical fires. They will actually only make these kinds of fires larger, which is totally counterproductive. Dry chemical extinguishers, on the other hand, can put out class A, B, and C fires. For this reason, they are sometimes referred to as multipurpose extinguishers. Carbon Dioxide extinguishers are capable of putting out class B and C fires only. There are handheld miniature fire extinguishers, too. These are often included in emergency kits and can be stored in your home and vehicle.