Once you have decided that a fire is safe to tackle and you have the right extinguisher, you need to use it correctly. Most extinguishers work in a similar way, but each type has its own technique and its own dangers.

Most portable extinguishers empty in less than a minute, so there is no time to work it out as you go. Knowing the technique in advance makes the difference between putting a fire out and making it worse.

In this module you will learn about:

• Checking an extinguisher before use.
• The PASS technique.
• Using water, foam, powder, carbon dioxide and wet chemical extinguishers.
• Using a fire blanket.
• What to do if the fire does not go out.
• Checking and maintaining extinguishers.

Take a few seconds to check:

• The label: is it the right type for this fire?
• The pressure gauge, if there is one: the needle should be in the green zone.
• The safety pin and tamper seal are in place, and there is no obvious damage.

Then carry the extinguisher by its handle, keep low to avoid heat and smoke, and approach the fire from the side where your exit is. Test that it works by giving a short burst before you reach the fire.

Once you have chosen the right extinguisher, carry out a few checks before use. Look at the pressure gauge and confirm that it is in the green, which shows the extinguisher is pressurised. Inspect it for damage, such as a broken hose or visible cracks, because a damaged extinguisher may not work and could be unsafe. Pull out the safety pin, twisting it if a plastic tag holds it in place, so that you can reach the trigger.

Make sure you have a secure and comfortable grip. Then give a short test discharge to confirm that it works. When you tackle the fire, start about two metres from the flames and move closer only as the fire dies down. Your safety comes first. If you lose confidence at any point, stop and evacuate.

Remember PASS:

• Pull: pull out the safety pin, breaking the tamper seal.
• Aim: aim the nozzle or hose at the base of the fire, where the fuel is, not at the flames.
• Squeeze: squeeze the handle firmly to discharge the extinguisher.
• Sweep: sweep the jet slowly from side to side across the base of the fire, until it is out.

Start about two metres from the fire, and move closer as the fire dies down. Keep your exit behind you at all times.

• Water: aim the jet at the base of the fire and move it over the burning area. Direct it at any hot spots, and keep going until the fire is out and cooled.
• Foam on solid materials: use it like a water extinguisher, aiming at the base of the fire.
• Foam on burning liquids: do not aim straight into the liquid, as this can splash burning fuel. Aim at a nearby surface, such as the back of a tray or a wall, so the foam flows gently over the liquid and forms a blanket.
• Never use water or foam on live electrical equipment or cooking oil.

Hold the hose by its handle and point it at the fire, with the cupped nozzle facing directly down. Squeeze the trigger to release the powder. Unlike other extinguishers, you do not aim at the base of the fire. Instead, sweep above the fire in a gentle circular motion so that the powder spreads evenly over it. This is especially important with metal swarf, because the gentle technique stops you from pushing the burning swarf around.

Keep going until the whole contents are used and the fire is completely out. These extinguishers are made for metal swarf fires, so never use any other type on burning swarf. The technique is identical for both, but know which you hold. The M28 deals with all metal fires except lithium, while the L2 deals with every metal fire, including lithium.

• Aim the horn at the base of the fire, or at the electrical equipment, and sweep it across.
• Never hold the horn itself. It becomes extremely cold and can freeze your skin. Hold the extinguisher by the handle, and on many models by the insulated part of the hose.
• The discharge is very loud. Be ready for it.
• Carbon dioxide replaces the oxygen in the air. In a small room, leave as soon as you have finished, and ventilate the room afterwards.
• The fire can re-ignite once the gas clears, so watch it carefully, and switch off the power if it is safe.

Before you discharge a CO2 extinguisher, set the horn at the right angle so that it stands upright by itself. Then hold the extinguisher only by its centre body and the trigger. Do not hold the horn, the pipework, the nuts and bolts or the base while it discharges, because during use these parts become extremely cold and can cause cold burns to your hands. This is why you position the horn first.

Squeeze the trigger and the gas flows towards the base of the fire. Sweep the horn from side to side, and carry on until the contents are used and the fire is fully out. CO2 extinguishers must not be used on metal swarf or on hot cooking oils and fats, which need specialised agents.

• Aim at the base of the fire and sweep from side to side.
• On burning liquids, do not aim directly into the liquid. Sweep the powder across the surface from the front edge.
• The powder cloud makes it hard to see and to breathe. Back away as soon as the fire is out, and do not use powder in small enclosed rooms.
• Specialist Class D powder extinguishers, such as M28 and L2, are used gently, with a low-velocity applicator, to cover burning metal completely without scattering it.

On burning solids, point the nozzle at the base of the fire and squeeze the trigger; on burning liquids, aim at a nearby surface, such as the back of a tray, so the foam flows gently across. Sweep from side to side so that the foam spreads evenly and smothers the flames, and keep going until the whole contents are used and the fire is fully out.

Do not stop early, because the flames must be completely suppressed. Foam must not be used on fires involving electrical equipment. The foam can conduct electricity and create a shock hazard, so use a carbon dioxide extinguisher for those fires. Do not use foam on fires involving free-flowing liquids unless you have had specific training, as without it the foam may not be effective. Always take a moment to read the label first, to be sure the extinguisher is correct for the fire.

• Turn off the heat source first, if it is safe to do so.
• Hold the lance or applicator above the fire, at arm’s length, about one metre away.
• Apply the wet chemical in slow, gentle circles, so that it falls onto the surface of the oil as a fine spray.
• Never spray it straight into the oil at short range, as this can splash burning oil.
• Keep going until the extinguisher is empty, so that a full layer forms over the oil and stops it re-igniting.

To use a wet chemical extinguisher, grasp the hose by its handle, stand about a metre from the fire, and point the nozzle downwards at the flames. Press the trigger and sweep gently in circles so the liquid spreads evenly. Continue until the flames are completely out, having first turned off the heat source, if it was safe to do so. Never use it on other types of fire, particularly electrical ones, because the liquid can conduct electricity.

To use a fire blanket, pull both tapes to release it, hold it at arm's length with your hands covered by the folds, and approach steadily. Lay it gently over the pan, away from you, without throwing it, and leave it undisturbed for at least 15 minutes. If a person's clothing is alight, wrap the blanket around them and tell them to stop, drop and roll. A blanket should only be used once.

• Pull both tapes sharply downwards to release the blanket from its container.
• Hold the blanket by the tapes, and wrap the top edges over your hands to protect them.
• Hold it in front of you as a shield, and lay it gently over the fire, away from you. Do not throw it.
• Turn off the heat source, if possible.
• Leave the blanket in place for at least 15 minutes, and until everything has cooled. Do not lift it to check.

If the extinguisher runs out, or the blanket does not put out the fire, or the fire starts to spread:

• Stop immediately. Do not try a second extinguisher on a fire that is growing.
• Leave the room, closing the door behind you to contain the fire and smoke.
• Leave the building, and go to the assembly point.
• Tell the person in charge and the fire service what happened: where the fire is, what is burning and what you used on it.

After any use, even a short burst, the extinguisher must be reported and replaced or refilled.

• Extinguishers should be visually checked regularly, often monthly, to make sure they are in place, undamaged, with the pin and seal intact and the gauge in the green.
• They must be serviced at least once a year by a competent person, in line with the Irish Standard IS 291, with a fuller test or replacement at set intervals.
• Never hide extinguishers, block access to them, or use them as door stops.
• Report any extinguisher that is missing, damaged, discharged or out of date straight away.