How to Understand Fire Extinguisher Codes

The code on a fire extinguisher tells you what kind of fire it will fight.

A fire extinguisher hanging on the wall often gives people the secure assurance that they can stop a small fire if it occurs. Before you grab that fire extinguisher, however, make sure you know what kind of fire you can extinguish with it. Fire extinguishers have labels that indicate what kind of fire they will put out. When you understand fire extinguisher codes, you will know what kind of fire will succumb to your fire extinguisher.

Instructions

1. Find on the white label on your fire extinguisher. Look for the alphanumeric code on the fire extinguisher.

2. Read the number that begins the code. This number indicates how much water is in the fire extinguisher to fight a type A fire. Every number represents 1.25 gallons. For example, a fire extinguisher labeled with "3A" has 3.75 gallons of water. The "A" represents fires of basic combustible materials that leave ashes behind, such as wood, cloth and other common household items.

3. Look for another number and other letters. A second number represents how many square feet the fire extinguisher can cover. Additional letters after this number indicate other types of fires you can put out with the fire extinguisher. A "B" represents flammable materials, a "C" represents electrical fires, a "D" represents metal fires (extremely dangerous) and "K" represents common kitchen fires. For example, a fire extinguisher labeled with "5B" could handle 5 square feet of a flammable fire.

4. Note a fire extinguisher with multiple numbers and letters. For example, the label "2A10BC" has 2.5 gallons of water for an ordinary combustible fire and it can cover 10 square feet of a flammable or electrical fire.

Tips & Warnings

• You may also see letters in colored shapes on the label, representing the same information.

References

• OSHA: Extinguisher Basics