The enduring image of napalm, often depicted in popular culture as an unstoppable force, raises a compelling question about its properties. Many wonder if this incendiary substance, known for its destructive capabilities, can truly burn even when submerged in water. Understanding the science behind napalm’s composition and its interaction with fundamental elements like water helps clarify this widespread perception.
What Napalm Is
Napalm is an incendiary mixture primarily composed of a gelling agent combined with a volatile hydrocarbon fuel, such as gasoline or jet fuel. The term “napalm” itself is derived from the original gelling agents used: aluminum salts of naphthenic and palmitic acids. This combination yields a sticky, gelatinous substance that adheres firmly to surfaces, enabling it to burn for extended periods.
Once ignited, napalm burns at very high temperatures, typically ranging from 800 to 1,200 degrees Celsius (approximately 1,470 to 2,190 degrees Fahrenheit). This intense heat, coupled with its adhesive nature, makes it particularly challenging to extinguish. Modern formulations, like Napalm-B, often incorporate benzene and polystyrene to enhance these properties.
The Fundamentals of Fire and Water
Combustion, the process we commonly refer to as fire, fundamentally relies on three components: heat, fuel, and an oxidizing agent, typically oxygen. This relationship is often visualized as the “fire triangle.” A fire can only ignite and sustain itself when all three elements are present in sufficient quantities. Removing any single component from this triangle effectively extinguishes the fire.
Water is commonly used as a fire retardant due to its ability to disrupt this triangle. When applied to a fire, water works primarily by cooling the fuel below its ignition temperature, thereby removing the heat element. Additionally, water turns into steam upon contact with intense heat, expanding significantly and displacing the oxygen surrounding the flames. This dual action of cooling and smothering makes water effective against most fires.
How Napalm Behaves in Water
While napalm is notoriously difficult to extinguish, its ability to burn underwater is largely misunderstood. For the vast majority of napalm formulations, continuous combustion underwater is not possible. This is because napalm, like most fuels, requires oxygen to sustain its burning process, and oxygen is scarce beneath the water’s surface. The fuel components within napalm are not self-oxidizing, meaning they do not contain an internal source of oxygen to fuel their own combustion without external air.
When ignited napalm comes into contact with water, its hydrophobic nature causes it to repel water and float on the surface. This allows it to continue burning as long as it remains exposed to atmospheric oxygen. If fully submerged, the water’s immediate cooling effect and, more importantly, its deprivation of oxygen will extinguish the flame. However, its sticky consistency means it can cling to objects and re-ignite if it resurfaces and regains access to oxygen.
Setting the Record Straight
Popular media often portrays napalm as a substance that burns indiscriminately, even underwater, contributing to a significant misconception. This dramatic depiction, while visually impactful, does not align with the scientific realities of how napalm functions. The idea of napalm burning relentlessly beneath the surface is a myth.
The fundamental requirement for combustion, including napalm’s, is access to an oxidizer, predominantly oxygen from the air. Water acts as an effective barrier, cutting off this oxygen supply and simultaneously cooling the fuel. Although napalm is engineered to be highly adhesive and difficult to remove from surfaces, making it devastating on land, its burning process ceases when fully deprived of oxygen by submersion. The persistent image of underwater burning largely originates from specific, less common formulations or from the general public’s misinterpretation of its intense, surface-level combustion.