The P.A.S.S. method is a standardized mnemonic device taught in fire safety training to help individuals remember the four proper steps for operating a portable fire extinguisher safely and effectively. This technique is universally recognized as the foundation for basic fire suppression, providing a straightforward procedure during the high-stress environment of an emerging fire. Following P.A.S.S. ensures the extinguishing agent is directed correctly to stop the combustion process. It is a fundamental element of fire safety, designed to stop a small fire before it can grow into a major threat.
Deciding Whether to Fight the Fire
Before even considering the P.A.S.S. method, a rapid safety assessment must determine if fighting the fire is appropriate and safe. The first step involves confirming that the fire is small, contained to its point of origin, and not spreading beyond an easily manageable size. You must also ensure you have the correct type of extinguisher for the specific fire class, as an incorrect agent can be ineffective or even worsen the situation.
A clear and unobstructed escape route must always be available behind you, allowing for an immediate retreat if the fire grows or the extinguisher fails. It is important to initiate emergency procedures, such as pulling the fire alarm and ensuring emergency services have been called, before attempting to suppress the fire. If you feel any hesitation or the fire is too large for a single extinguisher, your immediate priority must shift to evacuation.
The Four Steps of the P.A.S.S. Method
The first step in the P.A.S.S. method is Pull the pin, which is located at the top of the extinguisher’s handle and prevents accidental discharge. The pin is typically secured with a tamper seal that must be broken when the pin is pulled free, effectively arming the unit for use. This action unlocks the operating lever, allowing the pressurized contents to be released.
Next, you Aim the nozzle or horn low at the base of the fire, which is the source of the fuel. Aiming at the flames themselves is a common mistake, as the extinguishing agent will simply pass through the heat without breaking the chemical reaction. By targeting the base, you attack the material that is burning, which is the necessary action to extinguish the fire.
The third step is to Squeeze the operating handle slowly and evenly to begin discharging the extinguishing agent. Releasing the handle will stop the discharge, allowing the user to control the flow and conserve the limited supply of extinguishing agent. You should maintain a safe distance, typically starting about eight feet away, and gradually move closer as the fire begins to subside.
Finally, you Sweep the nozzle from side to side across the base of the fire until the flames appear to be completely out. This sweeping motion ensures that the agent covers the entire burning area, preventing re-ignition from overlooked hot spots. Once the fire is extinguished, you must continue to watch the area closely for any signs of re-ignition.
Matching the Extinguisher to the Fire Type
The P.A.S.S. method is only effective when the correct extinguishing agent is used, which depends on the type of material fueling the fire. Fires are categorized into classes based on their fuel source, and the extinguisher’s label indicates the class it is rated to suppress. Using a water-based extinguisher on a Class B fire, for example, can cause the burning liquid to splash and spread the fire.
A multi-purpose dry chemical extinguisher, often labeled ABC, is the most common type and is effective on ordinary combustibles, flammable liquids, and electrical fires. Understanding the fire class and selecting the appropriately labeled extinguisher is a prerequisite for successful fire suppression.
Fire Classes
- Class A fires involve ordinary combustibles like wood and paper.
- Class B fires are fueled by flammable liquids and gases.
- Class C fires involve energized electrical equipment, requiring a non-conductive agent.
- Class D fires involve combustible metals.
- Class K fires are specific to cooking oils and fats found in commercial kitchens.