Class A: Ordinary Combustibles

• Class A fires involve ordinary combustibles such as wood, paper, cloth, plastic or rubber. These fire extinguishers contain pressurized water. They are labeled with an "A" within a green triangle.
  
  

Class B: Flammable Liquids

• In Class B fires, flammable liquids such as oils, grease, solvents, gasoline and some paints, would be burning. These extinguishers contain pressurized carbon dioxide. Class B fire extinguishers are labeled with a red square containing a "B."
  
  

Class C: Electrical Equipment

• Class C fires are fires that involve electrical equipment such as computers, wiring or fuse boxes. They contain either carbon dioxide or dry chemicals. The labels of Class C fire extinguishers have the letter "C" within a blue circle.
  
  

Class D: Metals

• Class D fire extinguishers are specialty extinguishers that are used for fires involving shavings or flakes of combustible metals, which include titanium and sodium. These extinguishers contain a dry powder consisting of sodium chloride, but most are specialized to extinguish a specific metal. The "D" will be in a yellow decagon.
  
  

Class K: Combustible Cooking Fluids

• Class K fires involve burning cooking oils or fats. These specialty extinguishers are used in some restaurant kitchens because Class B extinguishers don't always work on fires in commercial cookers. Class K extinguishers may contain either dry or wet chemicals. They are labeled with a "K" in a black hexagon.