What Is a Fire Extinguisher?

Fire extinguisher are handheld devices that can be used to stop or reduce a fire from spreading. They do this by applying an agent that cools burning fuel, displaces or removes oxygen from the fire or disrupts the chemical reaction that causes a fire to burn.

There are a wide range of fire extinguishers available, from simple water extinguishers to more sophisticated dry powder or carbon dioxide extinguishers that are often used in motor vehicles and electrical equipment. There are also specialized models that can be used to fight specific types of fires, such as class B or class D. All are designed to help people escape the area before a fire takes hold and to limit the spread of a fire until emergency services arrive.

The most common type of fire extinguisher is a water extinguisher that works by cooling the burning fuel and materials by soaking them with water. They are a good choice for fires caused by various organic materials, paper and cardboard. They can be very effective and are easy to use, but they cannot be used on metals (classes F and D), or electrical equipment fires (class C).

Most jurisdictions require building owners and other property managers to install and keep a fire extinguisher handy in easily accessible places. They may also be required to check the fire extinguisher’s pressure regularly, typically every 30 days, and perform an annual inspection by a qualified technician who may recharge or replace the extinguisher. There are also electronic monitoring systems that monitor the physical presence and internal pressure of an extinguisher and can alert authorities to any problems, as well as hose reel covers for protection from the elements.

In addition, some manufacturers offer a variety of specialized models that are more durable and designed to be used by fire departments or other professionals in hazardous situations. These are often more expensive and can be customized with markings and colors to match the fire department’s brand.

The classification label on a fire extinguisher is an important guide to the type of fire it can be used on, and how large an area it can cover. For example, a fire extinguisher classified 1A:10B:C indicates it can be used on Class A and Class B fires and can be effective for up to 10 square feet.

The maintenance of a fire extinguisher is very simple. The can, hoses and nozzle should be kept clean and free of bugs and other debris. The extinguisher should be shaken monthly to prevent the powder from settling or packing, and the outside of the unit should be free of dirt, dust and oil. All extinguishers should be tagged or otherwise marked to indicate the date of last service, whether that service was for recharging, annual inspection or servicing, or replacement. Some extinguishers are high-pressure, and so are subject to additional safety requirements that include hydraulic pressure testing, periodic recharging and an external inspection by a certified technician.