• Fire extinguishers are labeled for proper use.fire extinguisher image by Chris Roselli from Fotolia.com
  
  Fire extinguishers are an important tool in front-line fire fighting. They can be used to put out small fires before they spread into major blazes. Fires come in various types; extinguishers do, too. For example, fires fueled by grease are handled differently than electrical blazes, according to the the U. S. Fire Administration website. Each type of fire needs the appropriate extinguisher to extinguish it safely and effectively.
  
  

Class A

• Class A fire extinguishers are the type used for ordinary combustible materials. They usually contain water and are appropriate for blazes fueled by paper, cardboard, wood and most plastics, the Fire Extinguisher 101 website explains. They are marked with a numerical rating that indicates their water capacity and how much fire they can handle.
  
  

Class B

• Class B fire extinguishers are used on fires fueled by flammable liquids like grease, oil, kerosene or gasoline, according to Fire Extinguisher 101. The liquids can spatter if doused with water, so these extinguishers contain foam, powder, carbon dioxide, sodium bicarbonate, potassium bicarbonate or monoammonium phosphate. They have a numerical rating that shows the square footage of fire that can be extinguished with their contents.
  
  

Class C

• Class C fire extinguishers are appropriate for use on electrical fires. They can be used on wiring, outlets, circuit breakers and appliances. Water causes electric shock risk, according to Fire Extinguisher 101, so they contain foam, powder, carbon dioxide, sodium bicarbonate or potassium bicarbonate. These extinguishing substances pose no shock hazard because they are non-conductive. Class C extinguishers do not have a numerical rating, according to Fire Extinguisher 101.
  
  

Class D

• Class D fire extinguishers are made specifically for use with combustible metals like sodium, magnesium, titanium and potassium. Fire Extinguisher 101 explains that they are typically used in chemical laboratories. They do not have a numerical rating, and they are sometimes made to handle fires involving a specific metal, according to the U. S. Fire Administration.
  
  

Class K

• The U. S. Fire Administration explains that Class K extinguishers are meant to extinguish blazes fueled by animal oils, vegetable oils or cooking fats. They are common in commercial kitchens in restaurants or cafeterias, and they are also sold for home kitchen use.
  
  

Multiple Class

• There is some overlap in the extinguishing material for certain fire types. Fire Extinguisher 101 explains that some extingishers are rated for multiple fires. For example, extinguishers that use foam or powder are appropriate for class A, B and C use. Sodium bicarbonate and potassium bicarbonate are both safe for class B and C use. Monoammonium phosphate covers classes A, B and C but it may harm computers or electrical devices because of the sticky residue it leaves behind.