Everybody who’s ever held a fire extinguisher before knows that there are four different extinguisher classes: A, B, C, and D. Each class designates the kind of fires the extinguisher can douse, but people often make the mistake that they’re arranged in some kind of order.
Because the classes have the appearance of being in alphabetical order, people assume that Class A extinguishers are somehow superior to the others. Fire fighters and safety educators need to focus on teaching people about what the different classes actually mean, and explain that there’s no such thing as an extinguisher hierarchy.
The “A” in Class A doesn’t represent its status of being the first fire extinguisher type, but actually stands for “Ash”. Class A extinguishers are water-based designed to fight flames caused by burning organic materials, such as wood and paper. In other words, Class A extinguishers can douse fires burning from anything that turns into ash. It is the most familiar extinguisher on the market, and the only commonly wholesale fire extinguisher.
Obviously, the “B” also stands for something as well, and that’s Barrel. It is designed to fight fires fed by flammable liquids and gasses. There are a few good reasons the people assigning codes for classes didn’t appoint something more straightforward, as is the case with Class A.
As B-class extinguishers could douse both flammable liquids and gasses, “L” and “G” were off the table. Class “F” was also out because that would only stand for flammable, which is extremely silly, considering anything that needs a fire extinguisher is already understood to be flammable.
The “C” stands for current, which makes sense since it is designed to fight electrical fires. Class C extinguishers are probably the most specialized of all the types, because electrical fires are the trickiest to deal with.
Class A water-types are useless, and though Class B extinguishers can smother the flames, they can’t completely neutralize the danger.
The “D” stands for dynamite, not because these extinguishers are the bomb, but because they’re designed to douse combustible materials. Fortunately, the demand for this class is limited, and restricted to establishments like firework factories.