Can an ABC Dry Chemical Fire Extinguisher Be Used to Put Out Class A, B, C & D Fires?

Read the instructions for fire extinguisher use before a fire.

One piece of equipment that you purchase for your home yet hope never to use is the fire extinguisher. According to the National Fire Protection Association, fires in homes in the U.S. caused $7.6 billion in damage in 2009. Home fire extinguishers can put out small contained fires but only if they have the rating for the type of fire they are used against. Use the wrong extinguisher and you could make things worse. A class ABC extinguisher can put out A, B, and C fires but not D.

Class D Fires

It is extremely unlikely that you would need a class D fire extinguisher in your home. You typically find them in factories and chemical laboratories. This type of extinguisher puts out fires that involve combustible metals. A building where people work with metals like titanium or potassium should have a class D extinguisher. This type of extinguisher sometimes contains ingredients specific to one type of metal.

Class ABC Extinguishers

The class ABC type extinguisher is a multipurpose extinguisher containing a dry chemical, monoammonium phosphate. It looks yellow and powdery and will leave a residue wherever it is used. The substance left by a dry chemical extinguisher will reduce the chance of re-ignition. This type of extinguisher is most often called into service for home use.

Extinguisher Types

For everyday materials like paper or cardboard, a type A extinguisher will work; it is filled with water. For fires of combustible liquids like grease or gasoline, use a class B extinguisher. Class B has a number rating that indicates how many square feet of fire it can put out. A class C extinguisher has a non-conductive material inside, making it safe to use on fires of an electrical nature. Class K extinguishers can be found in commercial kitchens for use on grease fires.

Agents Used Inside Fire Extinguishers

Air pressurized water, or APW, types of fire extinguishers have water in them, and rate class A only. Type BC extinguishers have sodium bicarbonate or potassium bicarbonate and pressurized with nitrogen in them. This leaves a residue that can damage items it lands on. Fast cleanup is essential to avoid more damage than the fire has already caused. Carbon dioxide-type extinguishers do not leave a residue. Use a CO2 type extinguisher on class B and C fires. This type is filled with pressurized carbon dioxide.

References

• Home Safety Council: How and When to Use a Fire Extinguisher
• National Fire Protection Association: The U.S. Fire Problem
• Fire Extinguisher 101: Fire Extinguisher Types

Resources

• U.S. Fire Administration; Fire extinguishers; May 2010