Napalm is an incendiary weapon—a thickened, flammable agent designed to maximize destructive thermal effects. Developed during World War II, its initial purpose was to create a substance that would stick to its target while burning intensely and for a sustained duration. This article examines napalm’s chemical makeup, the physics of its combustion, and the resulting physical and biological consequences.
Chemical Composition and Formulation
The core of napalm is a petroleum-based fuel, typically gasoline or jet fuel, combined with a specialized thickening agent. This agent transforms the volatile liquid fuel into a cohesive, sticky gel, preventing it from quickly running off a surface or evaporating.
The original formulation, developed in 1942, lends the weapon its name, a portmanteau of two constituents: naphthenic and palmitic acids. Combined with an aluminum soap powder, these acids acted as the gelling agent, creating a stable, flammable gel when mixed with gasoline. This original mixture was a tan-colored powder that was highly hygroscopic, meaning it absorbed water readily.
Following the Korean War, a more advanced version known as Napalm-B emerged, utilizing synthetic polymers as the thickening agent. This newer formulation often contained a mixture of gasoline, benzene, and a synthetic polymer like polystyrene. Polystyrene, a material commonly found in plastics, dissolves in the fuel mixture to create a thick, sticky gel, offering a more stable and longer-burning substance than the original aluminum soap mixture.
The Mechanism of Sustained Combustion
Napalm’s effectiveness stems from its ability to adhere to surfaces and maintain a prolonged, high-temperature burn. When ignited, the gelling agent creates a matrix that traps the fuel, preventing it from spreading out and exposing a large surface area to oxygen simultaneously. This mechanism slows the fuel’s rate of vaporization and combustion, ensuring a sustained thermal output rather than a quick flash of heat.
The thickened fuel’s adhesion to materials, including skin, is a primary factor in its destructive mechanism. Because the burning gel sticks to the target, it maintains continuous contact, preventing the heat from dissipating through movement or attempts at removal. Napalm can reach combustion temperatures ranging from 1,470 to 2,190 degrees Fahrenheit (800 to 1,200 degrees Celsius).
The high viscosity and hydrophobic nature of the gel make it difficult to extinguish with water. The thickener prevents water from penetrating the burning fuel matrix, often causing the flaming gel to float and spread the fire further. This sustained thermal exposure ensures that the heat penetrates deep into materials or tissue, causing extensive damage.
Immediate Physical and Biological Effects
Exposure to burning napalm leads to immediate, severe, and often fatal injuries primarily through sustained thermal exposure and secondary effects. The prolonged contact time of the hot, sticky gel results in deep, full-thickness burns, also known as third-degree burns. This sustained heat destroys all layers of the skin, including nerve endings, fat, and muscle tissue.
The difficulty in treating these burns is compounded because the burning agent adheres firmly to the tissue, making it nearly impossible to remove without causing further trauma. Victims suffer from widespread, severe burns that are highly susceptible to infection and require extensive, specialized medical intervention.
Beyond direct contact, napalm fires consume a significant amount of oxygen from the surrounding air while generating substantial quantities of carbon monoxide. This rapid depletion of breathable air and the presence of toxic smoke can lead to asphyxiation or severe inhalation injuries. High temperatures generated by the combustion can also cause thermal injury to the respiratory tract, even in individuals not directly coated by the gel.
Evolution and International Status
The formulation of napalm evolved from the original aluminum soap mixture to the polymer-based Napalm-B, which offered improved stability and adherence. This transition reflected a continuous effort to create a more effective incendiary weapon that could burn for a longer duration. While the United States military phased out the use of the older Napalm-B formulation, similar thickened fuel mixtures are still utilized as incendiary agents.
The legal status of napalm is governed by international humanitarian law, specifically Protocol III of the Convention on Certain Conventional Weapons (CCW). This protocol does not impose a total ban on the weapon but prohibits the use of incendiary weapons against civilian populations. The convention also restricts the use of air-delivered incendiary weapons against military targets located within a concentration of civilians.