Fire Extinguisher ABC’s – Weekly Safety Moment

Just as there is a right tool for every job, there is a right extinguisher for every fire. The class of an extinguisher,  identified on its nameplate, corresponds to the class or classes of fire the extinguisher controls. On most construction jobs, we are concerned with Class A, B and C fires. Consequently, the best extinguisher to have on a job is a multi-purpose Class ABC extinguisher, which contains a dry, powdered chemical under pressure. The following  describes the classes of fire and the kind of extinguisher that can be used on each.


Wood, paper, trash, and other materials that have glowing embers when they burn. Extinguisher to Use: For Class A fires, use a Class A or Class ABC extinguisher. Always remember that a Class A extinguisher contains water and should be used only on a Class A fire. If used on gasoline, it can spread the fire.  If used on electrical fires, it can cause you to be electrocuted.


These are fires involving flammable liquids and gases, such things as gasoline, solvents, paint thinners, grease, LPG, and acetylene. Extinguisher to Use: Use Class B or Class ABC extinguishers.


These are fires in energized  electrical equipment. Extinguisher to Use: Use a Class BC or Class ABC extinguisher.


  1. Use the fire extinguisher whose class corresponds to the class of the fire.
  2. Never use a Class A extinguisher, which contains water or foam, on a liquid or electrical fire.
  3. Know where extinguishers are located and how to use them. Follow the directions printed on the label.
  4. Keep the area around the fire extinguisher clear for easy access.
  5. Don’t hide the extinguisher by hanging coats, rope, or other materials on it.
  6. Take care of the extinguishers just as you do your tools.
  7. Never remove tags from extinguishers. They indicate the last time the extinguisher was serviced and inspected.
  8. Report defective or suspect extinguishers to your Supervisor, so that they can be replaced or repaired.
  9. When inspecting extinguishers, look for cracked hoses, plugged nozzles, and corrosion. Also, look for damage that may have been done by equipment running into the extinguishers.
  10. Don’t use extinguishers for purposes other than fighting fires.

Nobody wants a fire. But if one starts, know what extinguishers to use and how to use them!!

PDF version is available through the link below.

Safety Moment – Fire Extinguisher ABC’s