Using a Fire Extinguisher

We are all aware of the ways of dealing with fires, at least superficially. For example, we have seen in movies or documentaries how raging fires are quelled using fire extinguishers. You just seemingly pick one up, take the pin out and start spraying.

But in reality, how does a fire extinguisher work? What are its various types that exist, and what are their uses? Let us take a step-by-step look at the multiple characteristics of a fire extinguisher and the correct ways of using them.

 

What Causes a Fire?

There are three main components for a fire to take place. First, it needs fuel required to ignite and light the fire up and keep it burning. Secondly, it needs a sufficient amount of heat to ignite the flammable fuel.

And finally, it needs oxygen, in addition to fuel, to continue burning.

Cutting off the supply of any one of these is the best way to stop a fire.

 

How are Fires Classified?

Fires are classified based on their cause/fuel into four categories.

A - Wood, paper, cloth, trash, plastic

B - Flammable liquids, gasoline, grease, oil, acetone

C - Energized electrical equipment

D - Metals: Potassium, sodium, magnesium, aluminum

Types of Fire Extinguishers

1.   APW Fire Extinguishers

  • Air-pressurized water

  • Large, silver filled with 2/3 water

  • Pressurized with water

  • Two ft. tall and weigh approximately 25 lbs.

  • Class “A” fires only

  • They remove heat

2.   Carbon Dioxide Fire Extinguishers

  • Filled with non-flammable carbon dioxide gas

  • Recognized by the horn and lack of pressure gauge

  • 5lbs. to over 100lbs.

  • B and C fires only

  • Can cause freeze burns

 3.   Dry Chemical Fire Extinguishers

  • AB and ABC ratings

  • Coats fuel with a fine layer of powder agent such as Monoammonium Phosphate

  • Nitrogen is the typical pressurizing agent.

Rules for Fighting Fires

Always try and assist people in immediate danger due to the fire. Keep in mind to activate alarms and signals, if present, and use fire extinguishers on insipient-stage fires only.

Additionally, don’t try to fight the fire if the cause of the fire is unknown or the fire is out of control or spreading. Also, don’t fight a fire without the right equipment. Most importantly, always avoid it if you are uncomfortable with fire, smoke, or other prevailing conditions, even if the right equipment is present.

There are some rules that you should keep in mind when a fire breaks out:

  • In case of fire, pull the alarm or ask someone else to pull it.

  • Do not take the initiative into your hand unless you have been told, trained, or expected to fight the fires. Instead, follow the standard operating procedures.

  • Use a fire extinguisher only if you know/are trained to use one.

Finally, follow the PASS method for controlling fires:

  • Pull pin to release the discharge mechanism

  • Aim at the base of the fire

  • Squeeze the handle to release the extinguishing agent

  • Sweep the fire extinguisher back and forth across the fire.