The idea of using urine to extinguish a fire often sparks curiosity, particularly in hypothetical or survival situations. Many wonder if this readily available bodily fluid could serve as a makeshift fire suppressant. Understanding the properties of urine and the dynamics of fire reveals why this approach is generally ineffective and can even be dangerous.
The Limited Effectiveness of Urine
Urine is primarily composed of water, with the remaining percentage consisting of dissolved salts, urea, and other waste products. The water content is the only component capable of cooling a burning material and reducing its temperature, which is a fundamental principle of fire extinguishment. However, the limited volume of urine an individual can produce makes it insufficient for anything beyond the smallest flames. The small amount of liquid will evaporate quickly without significantly impacting a fire.
While the water in urine could dampen flames, the volume is too small to absorb enough heat to put out even a modest fire. Unlike a fire extinguisher, urine lacks the necessary quantity and pressure for effective fire suppression. The presence of dissolved solids like urea and ammonia also means that when urine hits a hot surface, it can produce an unpleasant odor as these compounds vaporize.
The Dangers of Urinating on Fire
Attempting to extinguish a fire with urine carries significant risks. One immediate danger is the creation of superheated steam when the water in urine comes into contact with intense heat. This steam can cause severe burns, especially if one is in close proximity to the flames.
Electrical fires are particularly hazardous, as urine is an electrolyte due to its salt content and can conduct electricity. Urinating on an electrical fire can result in an electrical shock or even electrocution, with the current traveling up the urine stream to the body. Approaching a fire to urinate on it places an individual in close proximity, which can expose them to intense heat and flames. If the attempt is unsuccessful, this delay can allow the fire to grow and spread, making it harder to control with proper methods.
Urinating on fires involving flammable liquids, such as grease or gasoline, can exacerbate the situation. Water, including the water in urine, should never be used on Class B (flammable liquids) or Class K (cooking oils/greases) fires because it can cause the burning material to splash and spread the fire. Getting too close to any fire exposes one to smoke and toxic fumes, which can be harmful. Smoke inhalation is a leading cause of fire-related fatalities, as smoke contains harmful particles and gases like carbon monoxide that damage airways and lungs, and reduce oxygen supply.
Proper Fire Safety and Extinguishing
For any fire beyond the smallest, immediately calling emergency services, such as 911, is an important step. Prioritizing personal safety, if a fire cannot be safely and quickly extinguished, evacuation is the primary course of action.
For small, contained fires, a fire extinguisher can be used effectively by remembering the PASS method:
Pull the pin.
Aim the nozzle at the base of the fire.
Squeeze the handle.
Sweep from side to side until the fire is out.
Fire blankets offer another safe alternative for smothering small fires, especially those involving cooking oils and fats, by cutting off the oxygen supply. These methods are designed for controlled fire suppression and prioritize safety, unlike improvised approaches such as using urine.