Fire Extinguishers

This is a quick guide - you should be trained to use an extinguisher! You should also know the number, kind and size of extinguishers in your area. Check them occasionally too.

Using Extinguishers.

In general, extinguishers are simple to use. You'll have to remove a locking mechanism of some kind (usually a pin) , aim at the base of the fire, and activate (usually by squeezing s lever/handle). When you are finished with the extinguisher, do not place it back in it's holder - lie it down - this is recognized as a sign the extinguisher is "dead". The Chief Warden must be notified of any use of an extinguisher (so it can get refilled). Even if you use one and the gauge still shows "green", the extinguisher is dead, is to be laid down and needs re-charging.

Note that one extinguisher does not put out much fire. If the fire is large, you will place yourself in great danger in attempting to deal with it - extinguishers are suitable for small fires only. It is probably a good plan to carry two extinguishers to the fire - one as a backup. Even better is to have a "buddy" with an extinguisher behind you. Extinguishers sometimes don't work!

Note that extinguishers operate only at short distances. This means you need to get close to the fire. This should ring warning bells! If you are going to try to deal with a fire personally, make sure someone else has gone to raise the alarm - you may need rescuing in the very near future. When in doubt GET OUT (but close the door when leaving, to help contain the fire).

To actually use an extinguisher - remember "PASS":

P - Pull the pin (and give it a "squirt" to make sure it's going to actually work)

A - Aim the extinguisher at the base of the fire

S - Squeeze the handle

S - Sweep back and forth, extinguishing as you go

Fire Extinguisher Problems

There are many reasons why extinguishers may not work, these include: the extinguisher is discharged (all types except CO2 have a pressure gauge), the chemicals in the extinguisher have "packed down", the locking mechanism is still in place, or the extinguisher is simply a dud.

In the face of panic, many people are unable to remove the locking pin: do NOT hold the extinguisher by the "handle" to do this - you tend to squeeze the handles together which locks the pin in place! This is the most common problem people encounter when trying to use an extinguisher for the first time (apart from aiming it at the burning material and "blowing" the burning material around the room). To remove the pin, rest your hand on the top of the cylinder, not on the handle itself. The pins are retained with a plastic strap which can be broken by twisting the pin. If you can't get the pin out, you can't use the extinguisher and you should be taking large steps away from the incident.

Quick Guide to Extinguisher Types

Note on types of fires

Fires are classified as type "A" or "B" or "E" fires in our environment. Class A fires are burning solids like wood, paper etc. Class B fires are burning liquids like Petrol and Class E fires are Electrical fires. There are other fire types ("C" - Gas fires, "D" - metal fires, "F" - cooking fats). Extinguishers are marked with the classes of fire they can be used on. They also give an indication of how big a fire they can deal with, eg: 4A(E) says the extinguisher can deal with a small class "A" fire and is also suitable for electrical fires. The bigger the number the bigger the fire. You should know the ratings of all your extinguishers - in particular, you should know which ones have the "E" rating, since this is the most likely kind of fire in our building! For (hopefully) obvious reasons, water based extinguishers can not be used on electrical fires, or near powered equipment. Be sensible and cautious - even if you believe the burning computer is now unplugged - treat it as live.

Types of Extinguisher:

You need to know this stuff - you can't risk using the wrong type of extinguishing agent on a fire or you'll make the situation worse and may involve yourself in the incident (by being electrocuted, for example).



Pressurised Water Extinguisher


(Class A)



Carbon Dioxide Extinguisher

(Class A,B,E)



Dry Chemical Extinguisher

(Class A,B,E or Just B,E)



Foam Extinguisher

(Class A,B)



Page last updated: 05/11/1999 Kevin Maciunas