Fire extinguishers are literally life-saving. They can keep something like a grease fire from evolving into something that shuts down a business, or worse, kills an employee. Not all fire extinguishers are created equal though, and many fire extinguishers will do various things others will not. Understanding how the fire extinguisher works, and what its code means will keep you from using the wrong fire extinguisher on a fire.
1. Class A: This fire extinguisher is one used for things like paper, wood, plastics and cardboard. This is used primarily for normal combustible items. Class A fire extinguishers are most often water fire extinguishers, so they should never be used to deal with grease fires, or electrical fires. Some Class A fire extinguishers use dry chemicals like foam, instead of water.
2. Class B: This type of fire extinguisher is used for combustible liquids like gasoline, grease and oil. This type of fire extinguisher is never a water extinguisher, and is most commonly a dry chemical extinguisher. Often, it is filled with sodium bicarbonate, potassium biocarbonate or monoammonium phosphate. Some Class B extinguishers are carbon dioxide extinguishers, which is a non-flammable gas.
3. Class C: This type of fire extinguisher is used for electrical fires from appliances, wiring, circuit breakers and outlets. These types of fire extinguishers are never water-based extinguishers and are primarily carbon dioxide extinguishers or dry chemical extinguishers.
4. Class D: This type of extinguisher is the type found in areas where chemicals like magnesium, titanium, potassium and sodium are used. These fire extinguishers use special chemicals to put the fire out properly. Water fire extinguishers are never used here.
5. Class K: This type of fire extinguisher is used for fires that come from cooking oils, and are most often found in restaurant kitchens.
Understanding what fire extinguisher to use in a fire can be the difference between life and death.