How Napalm Works

He loves the smell of napalm in the morning -- Robert Duvall as Lt. Col. Kilgore on the set of "Apocalypse Now."
Matthew Naythons/Getty Images

­Dep­ending on whom you ask, it's a noun, a verb, a chemical weapon, a tool to destroy crabgrass, a symbol of war's brutality or just a classic movie line. Napalm, with its varying forms and long history in warfare, is at once iconic and misunderstood. In this article, we'll take a look at napalm, from its origins to its contemporary use, and find out why it's known for its distinctive smell.

The security information Web site describes napalm as "a tactical weapon used to remove vegetative cover and instill fear." It comes from a powder that's mixed with gasoline (in some forms). Napalm, also called a firebomb fuel gel mixture, has a gel-like consistency, allowing it to stick to targets. Napalm is often used in combination with gasoline or jet fuel to make a bomb with a thin outer shell that easily explodes and ignites upon impact with a target. Once ignited, napalm can burn at more than 5,000 degrees Fahrenheit (2,760 degrees Celsius).


Military experts consider napalm particularly effective against fortified positions, like bunkers, caves and tunnels, as well as vehicles, convoys, small bases and structures. It clings to whatever it touches, creating a large, hotly burning area around the target. This feature also decreases the need for accuracy when dropping napalm bombs.

­U.S. and German forces used a precursor to napalm in flamethrowers during World War I. These weapons weren't considered effective because the flamethrowers' gasoline acted like a liquid, dripping off targets. Military leaders decided that they needed something to make fuels thicker.

The answer came from a team of scientists led by Dr. Louis F. Fieser. They created an aluminum soap mixed with naphthenic acid from crude oil and palmitic acid from coconut oil. (Take the "na" from naphthenic and "palm" from palmitic and you have "napalm"). The new agent, when combined with gasoline, made for a cheap, brutally effective weapon. It also could be shot long distances and was safer for the soldiers using it.

­Many militaries have used napalm in its various incarnations, but its use, especially in civilian areas, remains controversial. The 1980 United Nations Convention on Certain Conventional Weapons outlawed the use of napalm on civilians. Protocol III of the convention forbade the use of incendiary weapons like napalm on civilians. The United States ratified the convention but isn't party to Protocol III and has used napalm in many conflicts since the substance's invention.


Napalm's Effects on Health and the Environment

Egyptian soldier burned by napalm during Arab-Israeli war, being cared for at Helmia Military Hospital­
Charles Bonnay//Time Life Pictures/Getty Images

­­Napal­­m is an enormously destructive weapon. It'­s very stic­ky and can adhere to the skin even after ignition, causing terrible burns. Because napalm burns ­so hot,­ slight contact with the subst­ance can result in second-degree burns, eventually causing scars called keloids. The burns caused by incendiary weapons like napalm are tough for doctors to treat, according to Physicians for Social Responsibility [source: Crawley].

Napalm can cause death by burns or asphyxiation. Napalm bombs generate carbon monoxide while simultaneously removing oxygen from the air. The air in the bombing area can be 20 percent or more carbon monoxide [source:]. This effect occurs because napalm partially combusts the oxygen in the air, turning CO2 (carbon dioxide) into CO (carbon monoxide). In some cases, people have been boiled to death in rivers made hot by the heat of napalm bombs.


The raw ingredients of napalm can also be harmful, though certainly less so than when a napalm mixture is ignited as part of a bomb. If you've ever felt a little dizzy after breathing in fumes at a gas station, you can understand. But when polystyrene, another common ingredient in napalm, burns at high temperatures, it becomes styrene, which is toxic [source:].

Although one of napalm's early uses was agricultural -- Dr. Fieser found that it destroyed crabgrass by burning the invasive species' seeds while preserving other, necessary grasses -- it has largely proved destructive toward the environment. Fires caused by napalm can cause widespread ­damage. In Vietnam, the U.S. military took advantage of this fact by deploying napalm to destroy forests that North Vietnamese soldiers relied on for cover. The extensive use of napalm in Vietnam, along with Agent Orange, herbicides and a variety of unexploded landmines and munitions, are now believed to have contributed to that country's ongoing environmental and public health problems [source: King].

In the United States, the storage of unused napalm has proven a contentious issue. In 1998, protesters turned back trainloads of napalm on their way to recycling plants, perhaps fearful of napalm canisters leaking, as happened at the Weapons Support Facility, Fallbrook Detachment, in Southern California. This stockpile, supposedly the last batch of napalm in the U.S. arsenal, was dismantled and recycled in 2001.



Napalm in World War II and Korea

Allied napalm bombings decimated the city of Dresden, Germany.
William Vandivert//Time Life Pictures/Getty Images

­During World War II, U.S. forces used a 6 percent mixture of napalm in flamethrowers. Napalm bombs, a type of firebomb, became a prominent part of aerial campaigns later in the war. In 1944, Allied forces dropped the first napalm bombs on Tinian Island in 1944, which is part of the Northern Mariana Islands in the northern Pacific Ocean. Napalm devastated Japanese cities, especially since many houses were made of wood. A napalm bombing campaign against Tokyo on March 9, 1945, killed an estimated 100,000 people and burned 15 square miles (39 square kilometers) of the city [source: Laney].

Allied forces also used napalm in European fighting, with around 3.4 kilotons of napalm bombs -- up to 50 percent of bombs dropped -- falling on Dresden in February 1945 [source:]. The bombing, immortalized in Kurt Vonnegut's "Slaughterhouse-Five," was part of a controversial campaign in which between 35,000 and 135,000 German civilians died [source: Encyclopaedia Britannica].


U.S. forces found napalm useful against German bunkers. If the blast didn't kill the soldiers inside, the heat likely did. Similar tactics were employed against Japanese soldiers occupying Pacific islands, who used extensive underground tunnel systems.

­­If World War II was napalm's testing ground -- albeit a violent one that caused much destruction and loss of life -- then the Korean War was its true coming-out party. U.S. forces used a tremendous amount of napalm in Korea, ironically much of it made in Japan. During the conflict, U.S. forces dropped a quarter of a million pounds (113,398 kilograms) of napalm bombs every day, mostly in the form of the M-47 napalm bomb and the M-74 incendiary bomb [source:]. High-altitude bombers and dive-bombers unleashed them on enemy tanks and soldiers.

After the Korean War, the United States developed a more advanced form of napalm. This type of napalm wasn't made from naphthenic and palmitic acids (the source of the original napalm name). By then, napalm had already become a catchall term encompassing a variety of incendiary weapons, like when people say "Coke" to mean soda or "Kleenex" to stand for all facial tissues. Napalm-B, a napalm successor sometimes called super-napalm, NP2 or Incendergel, is made of 33 percent gasoline, 21 percent benzene and 46 percent polystyrene [sources: Browne,]. The gasoline in napalm is generally the same as that found at most gas stations, and that gasoline already has some benzene in it, but the benzene level is increased for napalm.

Napalm-B was considered safer than previous forms, although when the term "safe" is used in relation to napalm, it generally refers to those who deploy the weapon, not those against whom it's used. One of Napalm-B's safety features was that it was rather difficult to ignite, decreasing the chances of an accidental ignition. Thermite, a chemical mixture that burns at very high temperatures, is often used with a fuse to ignite Napalm-B.

Now, let's take a look at the use of napalm in Vietnam, where its controversial legacy was made.


Napalm in Vietnam

Kim Phuc, seen here with then-Sen. Joe Biden, stands in front of the famous photograph of herself as a child, being burned by napalm.
Scott J. Ferrell/Congressional Quarterly/­Getty Images

­The U.S. military used Napalm-B extensively during the Vietnam War -- up to 400,000 tons (362,874 metric tons) [source:]. In movies or newsreels from the era, you may have seen shots of planes diving low, then suddenly rising as enormous fireballs explode below. That's probably napalm in action. One retired U.S. Air Force Lieutenant Colonel, speaking to the San Francisco Chronicle, described the effect as "like a fiery blanket [that] burns everything that it hits" [source: Taylor].

Although the Vietnam War produced numerous images of bombs exploding and their aftermath, none is as indelible and well-known as that of Phan Thi Kim Phuc, taken by Associated Press photographer Nick Ut. Kim Phuc was 9 years old when she and fellow villager were napalmed accidentally by a South Vietnamese plane. In the famous picture, Kim Phuc and a group of children are running, fleeing their village. Phuc is naked, screaming because napalm is burning her body.


Upon realizing how hurt she was, Ut took Kim Phuc to a hospital. She survived but after enduring extensive third-degree burns and 17 operations. In her late teens and early 20s, the Vietnamese government used Kim Phuc as a propaganda tool, forcing her to speak to reporters from abroad. Eventually, she and her husband fled to Canada. She now lives in a suburb of Toronto, and although she still deals with pain from her injuries, she speaks publicly about the horrors of napalm [source: Omara-Otunnu]. She's also a U.N. Goodwill Ambassador. The photograph taken by Ut has become, along with images of burning monks, one of the most widely seen photos from the war.

The use of napalm in Vietnam helped to galvanize the antiwar movement in the United States. One target was Dow Chemical Company, which manufactured napalm for the U.S. government from 1965 to 1969. Protests against Dow and boycotts of its products occurred across the country. Company recruiters faced virulent protests on college campuses, in some cases finding themselves barricaded in buildings. In response to criticism, Dow said that it had a responsibility to the U.S. government to fulfill its requests for napalm. The company also claimed that napalm only represented a small fraction -- 0.5 percent -- of overall sales [source: BusinessWeek]. After Dow's contract expired, American Electric Inc. won the next government contract for napalm production. Some other companies that produced napalm for the government faced protests (and some did not submit bids for future napalm contracts), but no other company remains as linked with napalm as Dow.

­Although the U.S. government officially recycled its last batch of napalm in 2001, some contend that napalm is still in use today in ­Iraq.


The MK-77 and Napalm in Iraq

Napalm exploding in an area south of Saigon
Images like this one, of napalm exploding in an area south of Saigon, became well known during the Vietnam War, but napalm hasn't exactly died out since then.
Hulton Archive/­Getty Images

­Since its development, napalm has been used by many countries' militaries, including that of the United States, Angola, Nigeria, Brazil, Egypt], Israel, Argentina, Serbia, Turkey and possibly others. Today, America's sole incendiary bomb is the MK-77, or Mark 77 bomb. The MK-77 is a firebomb with a "thin skin" of aluminum [source: Iraq Analysis Group]. This "dumb" bomb -- as opposed to a precision-guided or "smart" bomb -- is a mix of 63 gallons (238 liters) of jet fuel (mostly kerosene) and 44 pounds (20 kilograms) of a polystyrene-type gel [source: Buncombe]. Although technically an incendiary bomb, the MK-77 is often referred to colloquially by soldiers and experts, and even in some military documents, as napalm. (Remember the previous discussion of napalm as a catchall term?)

During the Persian Gulf War, U.S. forces dropped about 500 MK-77 bombs [source:]. These bombs were used on trenches that Iraqi forces had dug and filled with oil. Iraqi soldiers were going to light these oil-filled trenches on fire when U.S. forces approached, but U.S. soldiers dropped napalm on the trenches to light them prematurely and clear the area. At the end of that conflict, Iraqi Kurds led a revolt against Saddam Hussein's government. In its reprisal attacks, Hussein's forces also used napalm to brutally crush the rebellious Kurds.


Although the U.S. military claims it hasn't used napalm in Afghanistan or the war in Iraq, some experts believe this distinction is simply a semantic one [source:]. They contend that while the old form of napalm isn't used, a similar, reformulated compound, also a jelled incendiary substance, has been used, most notably in the form of the MK-77 bomb.

In 2003, U.S. pilots admitted to using napalm on Iraqi soldiers. One American commander told The Independent newspaper that commanders like napalm for its "psychological effect" [source: Buncombe]. A Marine Corps Major General agreed that the United States had used napalm in Iraq [source: Crawley]. In the same article, a Marine spokesman said that Mark 77 bombs -- specifically the MK-77 Mod 5 used in Iraq -- were "remarkably similar" to napalm bombs (although less environmentally harmful), but referred to them as "firebombs" [source: Crawley].

There have been allegations that napalm was used when American forces assaulted Fallujah in November 2004 [source: Iraq Analysis Group]. But there has been considerable debate about whether this is true. U.S.-led forces may have instead used white phosphorous, another divisive incendiary weapon, rather than napalm [source: FAIR].

The use of napalm or napalmlike weapons has drawn some controversy for countries working with U.S.-led coalition forces who signed U.N. Protocol III but were working with or under the command of U.S. forces employing napalm. The eventual revelation that U.S. forces dropped MK-77 firebombs in the Iraq War angered British officials, who, in 2005, accused the U.S. of offering misleading information about the use of the MK-77 [source: BBC News].

Whatever the final verdict, napalm, like Agent Orange, has become a loaded word, symbolizing for many the carnage and brutality of war. During the Vietnam War, signs reading "Dow Shall Not Kill" and the photograph of Kim Phuc became icons of the antiwar movement. But despite the ghastly images we've seen, some experts on the subject point out that while napalm produces horrific results, it's used as part of waging war, which itself contains numerous images and symbols of horror, death and destruction. Yet even if napalm is a weapon like many others, something in particular about the substance and the images that have chronicled it, have lent it a special symbolism, unlikely to fade.


Napalm FAQ

Why was napalm used in Vietnam?
Napalm was used in Vietnam by American flamethrowers to burn down bushes and forests, neutralizing guerrilla fighters.
How do you treat napalm burns?
It's difficult to treat napalm wounds, as the chemical burns extremely hot. Doctors remove contaminated clothing to stop the continued burning.
What is napalm?
Napalm is a substance that can be used to create a bomb, also known as a firebomb fuel gel mixture. It has a gel-like consistency that allows the attacker to stick it to a target. It is mostly used in combination with jet fuel or gasoline to produce a bomb that ignites easily.
What does napalm do to humans?
Due to its sticky nature, it can stick to one’s skin even after ignition. That is why it produces awful burns on the human body. Even brief contact with napalm can cause second-degree burns, leading to keloids.
Why is it called napalm?
Chemists from Harvard invented napalm during World War II. Its name is derived from the first ingredients used to make it – aluminum salts of palmitic and naphthenic acids.

Lots More Information

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More Great Links

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