How to Use a Fire Extinguisher — The PASS Method

Short answer: PASS — Pull the pin, Aim at the base of the flames, Squeeze the handle, Sweep side to side. But the more important decision comes first and takes about two seconds: is this a fire you should be fighting at all? Most people injured in household fires were fighting one they should have walked away from.

Before you pull the pin, decide

Fight it only if all of these are true:

The fire is small — roughly wastebasket size or less — and not spreading.
Everyone else is already leaving, or is out.
The alarm has been raised and someone is calling the fire service.
You have a clear escape route behind you and can keep your back to it.
The extinguisher is the right type and you know how to use it.
There is no significant smoke in the room.

If even one of those is false: leave, close the door behind you, and call the fire service. A closed door buys real minutes. Smoke rather than flame is what kills most people, and two or three breaths of it can leave you unable to walk out.

PASS, step by step

P — Pull the pin. A plastic tamper seal holds it; a firm tug breaks it, with a slight twist if it resists. Do this with the cylinder upright and away from your face.
A — Aim at the base of the fire, not at the flames. Flames are the product; the fuel is at the bottom. Aiming high is the most common mistake and it empties the cylinder for nothing.
S — Squeeze the handle steadily. Letting go stops the discharge, which is useful — you are not obliged to empty it in one burst.
S — Sweep side to side across the base, advancing slowly as the flames drop. Keep sweeping until it is fully out.

Start 2 to 2.5 metres back (6 to 8 feet) and close in only as the fire shrinks. A typical home extinguisher delivers 8 to 15 seconds of discharge — that is your entire budget, and knowing the number in advance is what stops the silence catching you by surprise.

Once the flames are out, keep watching. Fires re-ignite, fabric and rubbish especially. Do not turn your back on it and do not go to bed.

Match the extinguisher to the fire

Class	Fuel	Use
A	Wood, paper, cloth, plastics	Water, foam, ABC dry powder
B	Petrol, oil, paint, solvents	Foam, CO2, ABC dry powder
C	Flammable gases	ABC dry powder — and shut the gas off
Electrical	Live equipment	CO2 or dry powder, never water
F / K	Cooking oil and fat	Wet chemical only

For a home, one ABC dry powder unit covers the widest range and is the usual recommendation; a small CO2 unit near electronics and a wet chemical unit in the kitchen are worthwhile additions. Class letters vary slightly between countries, but the fuel categories do not.

The kitchen exception matters enormously. Burning cooking oil is a class F fire, and hitting it with water — or with the wrong extinguisher at close range — produces an explosive boil-over. Never throw water on a grease fire, and know what to do when a pan catches fire: the lid and the heat switched off beat any extinguisher.

Keeping it usable

Mount it somewhere you would run past, near an exit — not in the cupboard behind the vacuum, and not beside the stove. You must be able to reach it without walking toward the fire.
Check the gauge monthly. The needle belongs in the green. It takes three seconds.
Invert and shake dry powder units a couple of times a year; the powder cakes.
Service or replace on schedule. The service life is printed on the label.
Any extinguisher that has been used at all must be recharged or replaced. A partly discharged unit bleeds pressure.

An expired or empty extinguisher is genuinely worse than none, because it commits you to fighting a fire you then cannot fight.

Frequent questions

Should I practise? Yes, whenever you get the chance — fire services and many workplaces run sessions with live trays. Ten minutes of practice changes your behaviour far more than any amount of reading.

Can I use it on someone whose clothes are alight? Stop, drop and roll, or smother with a blanket. CO2 can cause cold burns and dry powder is harmful to inhale. Use an extinguisher only if there is nothing else.

What about fire inside a wall or ceiling? Do not fight it. If flames are in the structure, the fire is already larger than the part you can see. Get out and call the fire service.

If I buy only one, which? A 2 kg ABC dry powder unit, plus a fire blanket for the kitchen. The blanket is cheap and handles the most likely fire in the house.

Is an extinguisher enough on its own? No. Working smoke alarms matter more, because they create the time in which any of this is possible — test your smoke alarms monthly.

Decide the whole plan before you need it: know what to do during a fire in a building, remember that shouting "fire" gets a response where shouting "help" does not, and keep the documents you would hate to lose in one fireproof folder.