Knowing how to use a fire extinguisher could save your
life in an emergency. It is also very important to have
fire a extinguisher at your home, workplace office etc. It
will go a long way to save life and property. So today I
will show you how to correctly use fire extinguisher.
The key to putting out a fire with an extinguisher is to
use the PASS strategy:
Pull the pin, Aim the hose, Squeeze the lever, and
Sweep the hose. However,
before you use a fire extinguisher to put out a fire, it’s
very important that you known whether or not it’s
appropriate for you to be fighting the fire, and whether
or not you'll be
able to put it out. If you don’t think you can fight the fire,
or if you have any doubts, leave the building
immediately
and call the fire department. This is save yourself first.
Tell someone else to call the fire department.
Evacuate everybody you could from the building. Tell
somebody to call the fire department or emergency
services once that person is safely outside. Even if
you're able to extinguish the fire on your own, it’s
important to have the fire department on the way in
case something happens.
When the fire department arrives, they can check that
the fire has been extinguished properly.
Stand with your back to an exit. Before you use a fire
extinguisher to put out a fire, it’s important to
take a couple safety precautions. Find the nearest exit,
and position yourself so your back is toward the exit.
This will help a lot if it goes beyond your control, try to
escape if you have
to. leave quickly in an emergency.
Just position yourself toward the nearest exit at all times
so you
know where it is and don’t get turned around or
disoriented.
Move to the proper distance. Many fire
extinguishers have a range of between 8 and 12 feet
(2.4 to 3.7 m). Before discharging the extinguisher,
move toward or away from the fire so you're standing 6
to 8 feet (1.8 to 2.4 m) away. You can move closer once
you start dousing the fire and the flames die down.

Source https://www.uchehub.com.ng/2017/11/how-to-use-fire-extinguisher-correctly.html?m=1