The correct sequence for operating a portable fire extinguisher follows a four-step method known by the acronym PASS: Pull the pin, Aim at the base of the fire, Squeeze the handle, and Sweep side to side. But the full sequence of actions actually starts before you ever touch the extinguisher, with a quick assessment of whether the fire is small enough to fight safely and whether you’re using the right type of extinguisher for the fuel that’s burning.
Before You Start: Size Up the Fire
Portable fire extinguishers are designed for incipient-stage fires, meaning fires that are just getting started. If the fire has spread beyond a single object, if the room is filling with smoke, or if your exit path is blocked, the extinguisher is not the right tool. Leave and call 911. OSHA requires that any workplace providing extinguishers for employee use also provide training on recognizing these limits, and the same logic applies at home.
You also need to confirm the extinguisher matches the type of fire. Fires are classified by what’s burning:
- Class A: Ordinary materials like wood, paper, cloth, rubber, and plastics
- Class B: Flammable liquids such as gasoline, oil-based paints, grease, and solvents
- Class C: Energized electrical equipment
- Class D: Combustible metals like magnesium, titanium, or lithium
- Class K: Cooking oils and fats in kitchen appliances
Most home and office extinguishers are labeled ABC, which covers the three most common fire types. Check the label on your extinguisher before you need it. Using the wrong class, like spraying water on a grease fire, can make things dramatically worse.
Check That the Extinguisher Is Functional
This takes about two seconds but matters. Most extinguishers have a small pressure gauge on the top. If the needle is in the green zone, the unit is charged and ready. If it’s in the red, the extinguisher may not discharge properly. Carbon dioxide extinguishers and some specialty Class D units don’t have gauges, so those rely on regular professional inspections and a weight check.
Also glance at the body of the extinguisher for visible damage, corrosion, or a broken seal. If anything looks wrong, don’t waste time with it.
The PASS Technique Step by Step
Once you’ve confirmed the fire is small, your exit is clear, and the extinguisher is the right type and properly charged, position yourself 6 to 8 feet from the fire (or at whatever distance feels safe while still being within the extinguisher’s spray range). Then follow these four steps in order.
Pull the Pin
Every portable extinguisher has a metal or plastic pin inserted through the handle assembly. This pin prevents accidental discharge. Twist or pull it free. Some models have a small tamper seal that will snap off when you pull. Don’t worry about being gentle; just yank it out.
Aim at the Base of the Fire
Point the nozzle, hose, or horn at the base of the flames, not at the top. The base is where the fuel source is. Spraying into the upper flames wastes your agent and does almost nothing to put the fire out. If you’re using a CO2 extinguisher, avoid gripping the plastic discharge horn directly, as it gets extremely cold during use and can injure your skin.
Squeeze the Handle
Press the two handles together to release the extinguishing agent. The discharge starts immediately. If you release your grip, the flow stops on most models, which gives you some control over how quickly you use up the contents. A typical home extinguisher holds only 8 to 15 seconds of spray time, so be deliberate.
Sweep Side to Side
Move the nozzle in a slow, controlled sweeping motion across the base of the fire from one side to the other. Don’t hold it in one spot. The goal is to cover the entire fuel source with the extinguishing agent, smothering or cooling the fire across its full width. Keep sweeping until the flames are completely out or the extinguisher is empty.
After the Fire Is Out
Don’t turn your back on it right away. Fires can reignite, especially with flammable liquids or deep-seated materials like upholstery. Watch the area for at least a minute. If flames return and you’ve already emptied the extinguisher, evacuate immediately.
Even if the fire appears fully extinguished, call the fire department to inspect the area. Fires can smolder inside walls, under floors, or in materials that look fine on the surface. A thermal camera check can catch hidden hot spots you’d never see.
Any extinguisher that has been partially or fully discharged needs to be recharged or replaced before it goes back into service. Even a brief squeeze can reduce the pressure enough to make it unreliable next time.
Why Aiming at the Base Matters Most
Of all four steps, aiming low is the one people most often get wrong under pressure. The instinct is to spray at the visible flames, which are the most dramatic and frightening part of the fire. But flames are a symptom. The fuel feeding them is at the bottom. Directing your limited supply of extinguishing agent at the base starves the fire of its heat source or coats the fuel so it can no longer release flammable vapors. Spraying at the top of the flames is like trying to stop a leak by mopping the floor instead of turning off the faucet.
This is especially critical given how little time you have. With under 15 seconds of spray in most residential extinguishers, every second of properly aimed discharge counts. Practicing the PASS sequence mentally, or better yet in a hands-on training session, makes it far more likely you’ll aim correctly when adrenaline is running high.