The standard UK method for using a portable fire extinguisher is built around four steps and a four-letter mnemonic: PASS — Pull, Aim, Squeeze, Sweep. The acronym is widely taught, but it is not the whole story. Knowing the four steps matters less than knowing whether to use the extinguisher at all, and recognising what is different about the unit in your hand once you do.

This page walks through PASS, sets out the assessment that has to come first, and covers what changes between extinguisher types — because the same four steps look quite different with a CO2 horn, a powder cloud, and a wet chemical lance.

What PASS stands for

The four letters break down to:

  • P — Pull the safety pin.
  • A — Aim at the base of the fire.
  • S — Squeeze the lever.
  • S — Sweep from side to side.

PASS is a useful reminder for many lever-operated extinguishers. Product instructions and training take precedence: the aiming method, operating mechanism and application technique vary with the equipment and fuel.

Before you pick it up: assess the fire

PASS is the second decision, not the first. The first decision is whether to fight the fire at all.

Three questions to run through, faster than they read on the page:

Has the alarm been raised? If the fire alarm hasn't been activated, do that first. Other people in the building need to know, and the response (evacuation, fire and rescue service called) needs to be in motion before you concentrate on a single fire point.

Is the fire at its earliest stage, and can I act safely within my training? Size alone cannot establish safety. Smoke, battery involvement, gas cylinders, an unknown fuel or rapid spread are reasons to withdraw. Portable equipment is not a substitute for calling the fire and rescue service.

Do I have a clear escape route? This is the question people miss most often. Keep the fire in front of you, with an unobstructed exit behind you. If the only way out is past the fire, do not engage — leave.

If any of those answers is no, the right action is to evacuate, close the door behind you, and call 999. Fighting a fire that is too big, with no exit, with the alarm not raised, kills people. It is not a failure of nerve to walk away; it is the standard advice from every UK fire and rescue service.

Pull

The pin (sometimes called a tamper seal pin) sits at the top of the extinguisher, below the lever. It is held in place by a small plastic tag that breaks when the pin is pulled. Often a quarter-turn or twisting motion makes the pin come out more easily — the tag is designed to break with that movement.

Pulling the pin does not start the extinguisher. It just removes the safety lock that prevents the lever from being squeezed accidentally. Until you squeeze, nothing comes out.

A missing pin or broken seal may mean the unit has been used, damaged or tampered with. Do not assume it will work. Report it for inspection; in an emergency, withdraw if suitable, serviceable equipment is not immediately available.

Aim

Aim at the base of the fire, not at the flames. This is the step people most often get wrong. Flames are the visible product of combustion; the chemistry that sustains the fire is happening at the fuel surface below. Spraying a fine cloud of agent through the air above the flames does very little. Hitting the burning material itself takes the heat (water), the oxygen (foam, powder, CO2), or the chemical chain reaction (powder again, in a different way) out of the fire triangle.

Use the operating distance and technique taught for that specific extinguisher, within its label limits. Do not approach into smoke or heat, and always preserve an unobstructed escape route behind you.

If discharge does not control the fire promptly, withdraw. Do not move closer simply to make the agent reach, and never allow the fire or smoke to cut off your exit.

Squeeze

Operate the control as instructed for the unit. Some agents and situations require a particular discharge pattern; there is no universal rule that every extinguisher must be emptied in one uninterrupted burst.

Discharge duration varies by capacity, model and agent and can be brief. Check it during training; do not rely on a generic number of seconds to decide how long it is safe to remain near a fire.

If the fire isn't out by the time the extinguisher is empty, that is the signal to evacuate. Do not try to find a second extinguisher and continue. By the time you locate, fetch, deploy a second one, the fire has had another minute to spread, and you are now fighting in a worse position.

Sweep

Sweep the discharge across the base of the fire from side to side. Two reasons for this. First, it covers a wider area — most fires are not a neat point source, and you need to address the whole burning surface. Second, it stops the agent from hitting one spot and bouncing off, which is especially a problem with water on a hard surface or foam on a flammable liquid.

Do not assume the fire is safe because visible flames have disappeared. Follow the taught application method while keeping a safe escape route, then withdraw and have the incident checked by the fire and rescue service.

Type-specific notes

PASS is a reminder for many common units; the operating and application method depends on the specific extinguisher. The differences that matter most:

Water and foam

A jet or spray nozzle, fired in a sweeping motion across the base of the fire. The discharge is heavy and wets surfaces — expect water on the floor and runoff after use. With foam, the sweep should leave a continuous foam blanket on a flammable liquid surface; if the blanket breaks, the fire can re-ignite through the gap. Use the trained technique and withdraw if conditions deteriorate; visible flame extinction does not prove the area is safe.

CO2

CO2 discharge can make exposed parts dangerously cold. Hold only the manufacturer-designated handles or insulated grips, following the unit’s instructions. The gas can displace oxygen, so confined spaces present an additional hazard. Its main extinguishing action is oxygen displacement, not sustained cooling.

Dry powder

The discharge is a thick, opaque cloud of powder that drastically reduces visibility within seconds. In an enclosed space, this can mean losing sight of your escape route, the fire, and the people behind you. The standard advice in BS 5306-8:2023 is that powder extinguishers should not normally be used indoors unless that risk has been mitigated through a health and safety risk assessment. Use a dry powder extinguisher in earnest, and you will spend the next hour cleaning powder off everything in the room.

Wet chemical

Wet chemical extinguishers are supplied with a long lance rather than a short nozzle. The lance is there for a reason: it lets you apply the mist from a safe distance to a hot oil fire without the discharge force splashing burning oil out of the pan. Don't try to use a wet chemical extinguisher up close like a foam unit — keep the lance extended, point the mist into the burning oil, and let the saponification chemistry do the work. (More on that on our wet chemical fire extinguisher page.)

Water mist

Sweep the mist across the fire as you would water, but expect a finer, gentler discharge. Water mist works through a combination of cooling, oxygen displacement, and rapid steam generation; it doesn't drench surfaces the way bulk water does. A fine mist does not make entry into smoke or a confined fire area safe.

When not to fight a fire

A short list, worth memorising:

  • The fire is bigger than waste-bin or chair-back size.
  • The fire has reached the ceiling, the walls, or another room.
  • The room is filling with smoke that obscures vision or makes breathing difficult.
  • The only escape route runs past the fire.
  • The right type of extinguisher isn't immediately to hand.
  • You haven't been trained to use the extinguisher in front of you.
  • You are alone in the building, or others haven't been alerted yet.

Any one of these is a reason to evacuate, close the door behind you to slow the spread, raise the alarm, and call 999. None of them are a reason to feel embarrassed afterwards. The duty for almost everyone in a UK workplace is to evacuate safely; only people designated and suitably trained under the premises’ plan should consider using extinguishers on incipient fires. There is more on that distinction on who is responsible for fire extinguishers in UK workplaces.

Why training beats reading

PASS can be learned from a page. Using a fire extinguisher confidently in the actual seconds of a fire is harder, and that gap is the whole reason fire safety training exists.

The Regulatory Reform (Fire Safety) Order 2005 requires employers to provide adequate fire safety training to all employees, including how to react to a fire and the basics of fire safety equipment. For most staff, that does not mean live-fire practice — it means knowing the alarms, the escape routes, the assembly point, and the principle of when to fight versus when to flee. Our online fire safety awareness training course covers exactly that ground for UK workplaces, in 90 minutes, RoSPA-approved and CPD-accredited.

For nominated fire wardens and fire marshals, training goes further — practical extinguisher handling, evacuation leadership, and post-incident duties — and is normally provided as a separate course.

The point is that nobody learns to drive from reading the Highway Code. The same applies here. PASS gives you the framework; training gives you the muscle memory.

Frequently asked questions

What does PASS stand for?

Pull, Aim, Squeeze, Sweep — the four-step technique for operating a portable fire extinguisher. Pull the pin, aim at the base of the fire, squeeze the lever, sweep across the burning material.

How close should I stand to a fire when using an extinguisher?

Follow the distance, grip and application instructions on the specific unit and your practical training. Do not approach into heat or smoke; maintain a clear exit and withdraw if conditions are unsafe.

When should I not try to put out a fire?

Anytime the fire is bigger than waste-bin size, has spread, is filling the room with smoke, or is between you and the only exit. Anytime you are alone with the alarm not yet raised. Anytime the right type of extinguisher isn't immediately available. Evacuate, close doors, call 999.

Does PASS work for every type of extinguisher?

PASS is a reminder for many common units, not a universal operating procedure. Foam on liquid fuel, wet chemical on cooking oil and specialist agents need their own techniques. Follow the manufacturer’s instructions and training.

How often should I refresh fire safety training?

Training must remain adequate for the risks and be repeated where appropriate. Review it when roles, equipment, hazards or arrangements change. Set refresher timing through the fire risk assessment; the Fire Safety Order does not prescribe a universal annual interval.

Where this connects

If you have read this far and want the next layer of detail, the most useful next steps are:

And if it is your team's training that needs sorting, the online fire safety awareness course is the place to start — every UK employee needs the basics, and ours delivers them in 90 minutes with an instant certificate.

Sources & references

Official guidance and standards checked on 15 October 2026.

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Mark McShane
Mark McShane
Health & Safety Training Specialist, Online CPD Academy

Mark writes about workplace health & safety, fire safety awareness and accredited online training for Fire Safety Awareness Training, part of Online CPD Academy.