While you might think that a fire is a fire plain and simple this isn’t always the case. In fact, there are 5 different basic classifications for fires and each of them has a unique response. In some situations using water to try to extinguish a fire can make it even more hazardous. Fortunately there’s always a proper response it’s just about being prepared ahead of time. Here we’ll look at each of the different fire classifications as well as the proper response.
Class A fires are what you think of when you hear fire. These fires involve common combustible materials like paper, wood, cloth, rubber, trash, and plastics. This is the most common type of fire for homes and businesses and fortunately also the easiest to manage and deal with. These fires are best managed with water or the standard ABC fire extinguisher.
Class B fires involve typically flammable gasses. Some examples of combustibles that create class B fires include: oil, gasoline, paint, solvents, lacquers, tars, and other synthetic oil based products. These fires are typically more dangerous than class A fires because they can spread very quickly and even reflash after the flames are extinguished. The best way to manage this type of fire is with carbon dioxide or dry chemical ABC extinguishers. Pressurized water is a really bad idea for class B fires because it can further spread the flammable material and help the fire get out of control.
Class C fires are basically electrical fires. This is a little bit more difficult to explain because they aren’t classified based on the combustible material like the others but rather by the source that starts the fire. However, it does merit special consideration for extinguishing an electrical fire because again water is problematic unless you first turn off the electricity. Dry chemical or carbon dioxide extinguishers are best suited to class C fires.
Class D fires are also often called metal fires and usually start from metal powders (sodium, potassium, magnesium, titanium, and zirconium are the most common) and require very specific methods to extinguish. These fires require specialized class D extinguishers which use a dry agent like sand, limestone, graphite, or sodium carbonate. Any other method has a high risk of reacting with the metal and worsening the fire.
Class K fires are generally referred to as cooking fires as they stem from cooking oils and grease. These fires burn extremely hot and have a chance of reflashing if not properly extinguished. A special wet chemical extinguisher is typically used to combat class K fires.