What Fire Extinguisher to Use: The Different Types of Fire Extinguishers
- Luke Song
- Oct 20
- 2 min read
When thinking of quelling a fire, fire extinguishers often come to mind. Indeed, they are incredibly helpful tools, helping to stop fires before they become too large and impossible to control. But how much do we actually know about fire extinguishers? While they all serve the same general purpose, not all fire extinguishers are the same. Since fires are caused by a variety of factors, a variety of fire extinguishers, naturally, is needed. Understanding these differences is crucial; in fact, using the wrong extinguisher can actually worsen a fire rather than put it out.
Depending on the type of burning object, fires are grouped into several classes. Class A fires involve ordinary materials such as wood, paper, cloth, or plastics, while Class B fires occur when flammable liquids such as gasoline, oil, or paint catch on fire. Furthermore, Class C fires are electrical by nature and occur when wires, outlets, or appliances catch fire, and Class D fires involve combustible metals such as magnesium or titanium. Finally, Class K fires occur in kitchens, where cooking oils and fats ignite.
One of the most common types of fire extinguisher uses water and foam. Water extinguishers are used primarily on Class A fires, as they cool the burning object and remove heat. However, since water conducts electricity and thus spreads flammable liquids, they should not be used on electrical or grease fires. Foam extinguishers are slightly more versatile, as they work on both Class A and B fires. Forming a barrier over the burning liquid, the foam cuts off oxygen supply and prevents vapor from escaping.
Additionally, carbon dioxide extinguishers are also common, and they are used for fires involving electrical or flammable materials. Carbon dioxide displaces the oxygen around the fire and cools the fuel, allowing for quick and clean extinguishing of fires, as it leaves no residue. Thus, they are extremely effective indoors, but much less so outdoors due to the wind’s dispersal of the gas.
Dry chemical extinguishers are also widely used since they can deal with multiple classes of fires. The ABC type, which contains monoammonium phosphate powder, fights fires involving sundry combustibles, flammable liquids, and electrical equipment by interrupting the progression of the fire. Other types of extinguishers, such as BC powder extinguishers, are used in industrial settings for liquid and electrical fires but are less effective on solid materials.
Wet chemical extinguishers are designed specifically for kitchen use, particularly Class K fires. These fires often involve deep fryers or cooking oils that burn at extremely high temperatures. To combat this, the wet chemical solution cools the oil and forms a soapy layer that prevents the fire from reigniting. Similarly, clean agent or Halotron extinguishers are popular in areas with sensitive electronics because they leave no residue and do not damage equipment.
Knowing the differences between fire extinguishers is an essential aspect of safety. All extinguishers are labeled with the types of fires they can control, and learning these labels can easily make the difference between a small incident and a disaster.
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-Written by Ethan Liang
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