Using a fire extinguisher on a person is generally not advised and can cause severe injury, despite the immediate need to put out flames. Fire extinguishers are engineered to suppress combustion, not to interact safely with human skin, eyes, or respiratory systems. While the instantaneous force of the discharge might halt a life-threatening fire, the secondary physical and chemical damage often outweighs the benefit. Understanding the specific dangers involved illustrates why alternative methods are preferred for personal fires.
Hazards of Pressurized Discharge
The immediate physical danger from a fire extinguisher comes from the sheer force and nature of the propellant discharge. Extinguishers are high-pressure devices designed to project their contents over a distance, and the kinetic energy of this stream can cause significant trauma. Direct contact with the high-velocity stream can result in internal injuries, severe eye damage, and deep soft tissue damage, even from several feet away.
Carbon dioxide (\(\text{CO}_2\)) extinguishers pose a unique and immediate temperature-related hazard. The \(\text{CO}_2\) is stored as a liquid under high pressure and, upon release, expands rapidly, causing its temperature to plummet to approximately \(-78\,^{\circ}\text{C}\) (\(-109\,^{\circ}\text{F}\)). Direct skin exposure to this extremely cold agent results in instant cryogenic burns, or frostbite, which can lead to permanent tissue damage requiring specialized burn treatment.
The discharge of dry chemical extinguishers, which are the most common type, creates a sudden and dense cloud of fine powder. This fine particulate matter immediately impairs visibility and creates a high risk of respiratory obstruction. Inhaling the dense powder cloud can cause rapid breathing difficulty and disorientation, especially in enclosed spaces, which may lead to suffocation or panic. The compressed gas used to propel the agent can also displace oxygen in small areas, increasing the risk of asphyxiation for everyone present.
Specific Chemical Agent Toxicity
The chemical makeup of extinguishing agents presents significant health hazards upon contact or inhalation. Dry chemical powders, such as those found in common \(\text{ABC}\) extinguishers, primarily contain monoammonium phosphate. While often described as non-toxic in small amounts, this fine powder is highly irritating to mucous membranes, eyes, and skin.
Inhalation of monoammonium phosphate can cause irritation to the nose, throat, and lungs, leading to coughing and shortness of breath. Symptoms are more severe for individuals with pre-existing conditions like asthma. Large exposure has been linked to severe systemic toxicity, requiring immediate medical intervention.
Other types of extinguishers carry specific chemical risks. Foam and wet chemical agents contain various surfactants designed to cool and smother fires. Direct exposure can cause severe irritation and chemical burns to the eyes, potentially leading to lasting vision damage. Removing the sticky, caustic residue from the skin and hair prolongs irritation and increases the potential for secondary skin infections.
Protocol for Personal Fires
When a person’s clothing catches fire, the safest procedure is the “Stop, Drop, and Roll” technique. The person should immediately stop, drop to the ground, and cover their face to protect their airway and head. They must roll continuously until the flames are extinguished, which smothers the fire by depriving it of oxygen. Running or standing up will fan the flames, making the fire worse.
If the person cannot perform this action, the fire should be smothered using a non-synthetic material. A fire blanket, heavy coat, or rug can be wrapped tightly around the person to cut off the fire’s oxygen supply. Synthetic fabrics should be avoided for smothering, as they can melt and fuse to the skin, causing more severe burns.
Clean water is the preferred extinguishing agent if it is immediately and readily available, such as from a shower or hose. Water works by cooling the burning material and the skin, which helps to minimize the depth of the burn injury. Applying cool water to the burned area for several minutes is also the first aid protocol after the flames are out.