Fire extinguishers are practical devices that assist in the prevention of small fires from becoming massive fires that may lead to further damages. Knowing what type of fire extinguisher to use for a particular fire type can be a lifesaver in the event and prevent a small fire from turning into a large blaze. The fire extinguishers are classified into classes of fire and types depending on the kind of fire that they are required to put out. In order to use them effectively when needed, one needs to know what they are and how they function.
Class A Extinguishers
The ordinary combustibles fire extinguisher is also known as Class A extinguisher and it is used in cases where the fire involves wood, paper, cloth, trash or plastics. The number accompanying the class A extinguisher explains the volume of water the extinguisher contains and the degree of fire it can put out. Some of the chemicals are the mono ammonium phosphate, which has the role of cooling the fire, and the ammonium sulphate which goes further and inhibits the combustion process. These substances are also released as fine powders as opposed to jets of liquids; in the process they can put out fires by creating a layer over the fuel and the oxygen. Class A fire extinguishers are available in different sizes from portable lightweight fire extinguishers meant for small trash container fires to heavy duty trailer mounted extinguishers for commercial buildings and warehouses.
Class B Extinguishers
Class B extinguishers are used in cases of flammable liquids, gases, greases, oil based paints etc, The contents of these devices may include sodium bicarbonate, potassium bicarbonate or potassium chloride. When applied, they react with the fuel with the aim of denying it contact with oxygen through forming a layer of chemical compound. Class B fires cannot be tackled with water as it will instead aid in the spreading of the fire. Similar to class A device, class B extinguishers also have a numerical rating; nonetheless, it is the approximate square footage of a flaming liquid fire that the extinguisher can handle. There are wheeled and portable types of class B extinguisher, with the wheeled ones typically found in garages, laboratories, commercial kitchens and other places where flammable liquids are dealt with.
Class C Extinguishers
These fire extinguishers are for use in electrical fires, where the equipment is still live with electricity and includes appliances, fuse boxes, wiring, circuit breakers or outlets. They have additives like the carbon dioxide and dry powder which do not conduct electricity back to the person handling them. Class C devices work by breaking the fire triangle by eliminating the element of heat, and are not associated with the risk of electric shock from using water or foam. These are usually mixed with class A and B type extinguishers They are either designed to tackle class A, B or C type fires. The numerical rating that is associated with the extinguishing agent is the volume of the extinguishing agent and the current capacity that it is safe to extinguish. There are class C fire extinguishers that are small unit for homes to large wheeled ones for commercial use and industrial purposes.
Class D Extinguishers
Some of them include magnesium, sodium, aluminum, titanium, potassium, and other metals that can easily catch fire at high temperatures and which need specific fire fighters to put out the fire. Class D extinguisher is filled with powdered graphite, copper dusts, dry sand and soda ash etc. , which puts out a fire by removing the fuel and denying it access to oxygen. It helps extinguish the fire and formation of a crust to reduce chances of rekindle. This type of extinguisher is placed near areas where combustible metals are in use for example in industries that deal with aluminum melting, airplane manufacturing, metal cutting die, among others. The rating of this type of extinguisher is measured in terms of weight and volume of the combustible metal that it is capable of putting off.
Class K Extinguishers
Cooking equipment that uses vegetable oils or animal fats used in commercial kitchens is prone to explosion of grease fires. Type B and C extinguishers put out fire through means of removing the fire’s source of oxygen however, they may not effectively lower the temperature of the dangerously hot oils enough to avoid reignition. Class K fire extinguisher consists of alkaline agents such as sodium, potassium, and base liquids such as sodium potassium acetate that are particularly suitable for hot grease fires. They beat the heavy oils into a foam which dribbles over the appliance and sets on all the hot areas. The rating for class K devices is expressed in terms of the fire size in square feet (two numerical values) for Stainless Steel grill and lightly/heavily breaded oils. It fasts and eliminates fires and their likelihood without compromising on apparatus. It is used mostly in commercial kitchens that use high horsepower griddles and fryers.
Wet Chemical Extinguishers
Another type of device, which is becoming more popular, is wet chemical extinguishers used for commercial kitchen. It is very useful for extinguishing grease fires in stoves, grills, fryers etc The big red cylinder houses an alkaline solution that gels OIL grease fires and turns them to soap to avoid flare ups. The fine mist also helps to prevent splashing and distribution of hot grease and oil all over. While it works in a way that is similar to a class K extinguisher, the wet chemical type cools hot surfaces more quickly than the other types. In addition, it is flexible compared to other powders; its wet mist is safer near the food. The extinguishers take little effort to maneuver and put out fires in mere seconds; these should be available in restaurant and cafeteria-style kitchens.
Carbon Dioxide Extinguishers
Carbon dioxide or CO2 extinguishers operate on the principle of taking out oxygen and heat and not on the chemical precordial interruption of the burning process. It is discharged in a snow like structure of carbon dioxide particles and immediately on discharge, the carbon dioxide particles turn into heavy gaseous state. This helps to stop the fire and also reduces the amount of oxygen that is supplying the flame. This fact makes CO2 extinguishers perfect for temperature and humidity control in areas that contain sensitive electronics and documents since it leaves no residue. There are also portable CO2 extinguishers intended for use in homes, particularly those used in extinguishing stove top kitchen fires. They normally contain a horn which can be used to signal evacuation after putting out the fire.
Summing up, it is crucial to raise awareness of the different sorts of special-use fire extinguishers and how they can be used in a fire emergency. The small battery-powered units for households to the large castor type used in industries and commercial buildings have their uses. Using this basic knowledge one can effectively put into use the suitable firefighting device for putting off the fire in the initial few minutes. Time will not be wasted if we get to know about them because it will be of great help in fire safety.
