CO2 or Dry Chemical Extinguisher - Class B Fires

A CO2 or dry chemical portable fire extinguisher is used to put out Class B fires fueled by flammable liquids, such as:

• Oil
• Gasoline

These fire extinguishers deprive the fire of oxygen and interrupt the fire chain by inhibiting the release of combustible vapors. One example of this type of extinguisher is an extinguisher filled with CO2, a non-flammable gas under extreme pressure. Because of its high pressure, when you use this extinguisher, pieces of dry ice shoot from the horn, which also has a cooling effect on the fire. You can recognize this type of extinguisher by its hard horn and absent pressure gauge.

CO2 cylinders are red and range in size from five to 100 pounds or larger.

Extinguishers that are suitable for Class B fires are identified by a square containing the letter "B."

It is important to remember the instances in which it is not suitable to use a Class B or Class C CO2 portable fire extinguisher, such as:

• For a Class A fire, because these fires may continue to smolder and re-ignite after the CO2 dissipates
• In a confined space while people are present without proper respiratory protection

To learn more about Fire Extinguishers visit our Portable Fire Extinguishers Online Training web page.