When you think of a fire, you may think of a basic wood-burning fire, such as one found in a fireplace.
However, there are several different types of fires with different characteristics that many people may not be aware of.
Depending on the fuel that propagates the fire, a different type of extinguishing agent may be needed to put it out.
To differentiate fire types, fire departments around the world have developed fire classification systems.
Below is a description of the fire classes used in the Unites States today.
Fire Classes and Their Extinguishing Agents In the U.
S.
, fires are classified into five different categories.
These five classes are distinct and each type behaves differently.
The five classifications are broken down as follows:

• Class A: Ordinary combustibles (wood, cloth, rubber).
  Extinguished using water, foam, or ammonium phosphate.
  
• Class B: Flammable liquids and gases (gasoline, natural gas).
  Extinguished using a dry chemical agent, carbon dioxide, or foam.
  
• Class C: Electrical equipment.
  Extinguished by carbon dioxide and dry chemical powders.
  
• Class D: Combustible metals (sodium, steel, magnesium).
  Extinguished using dry powder agents, such as graphite powder or sodium chloride (salt) granules.
  
• Class K: Cooking oil or fat.
  Extinguished using saponification or a dry powder such as baking soda.
  

It is important to know which extinguishing agents can be used on which types of fires, because using the wrong agent can be disastrous.
In fact, it can often make the situation worse.
For example, in a Class K oil or grease fire, never use water to attempt to put it out.
Water will vaporize immediately and cause the oil or grease to scatter, engulfing the area in flames.
If you have a fire extinguisher, it will indicate on the label which class(es) of fire it can extinguish.
For More Information Knowing how to react to different classes of fires and having the appropriate extinguishing agents on hand can be a life-saving investment.