MK77 750lb Napalm
MK78 500lb Napalm
MK79 1000lb Napalm

A fire bomb is a thin skinned container of fuel gel designed for use against dug-in troops, supply installations, wooden structures, and land convoys. Fire bombs rupture on impact and spread burning fuel gel on surrounding objects. MK 13 Mod 0 igniters are used to ignite the fuel gel mixture upon impact. The Mk-77 is the only fire bomb still in service, replacing the BLU-27.

While the MK-77 is the only incendiary munition currently in active inventory, a variety of other incendiary devices were produced, including the M-47 Napalm bomb, the M-74 incendiary bomb, and white phosphorous and munitions manufacturing. Production of these devices continued during the Korean conflict, though various demilitarization and decontamination programs were initiated in the late 1950s. Munitions destroyed included M-47 Napalm-filled bombs and incendiary cluster bombs.

The containers of napalm bomber are very light and fabricated of aluminum, with a capacity for about 75 gallons of combustible gel. They lack stabilizing fins, and consequently acquire a tumbling motion on being dropped that contributes to the scattering of the combustible gel over a wide area.

Napalm is a mixture of benzene (21%), gasoline (33%), and polystyrene (46%). Benzene is a normal component of gasoline (about 2%). The gasoline used in napalm is the same leaded or unleaded gas that is used in automobiles. Gasoline is a mixture of hydrocarbons, which burn in an engine. It is a clear liquid, made from crude oil that burns and explodes easily. It naturally contains some benzene (which makes gas smell the way it does). Gasoline is lighter than, and floats on, water, but it will not mix with water. It dissolves grease and oil but will not dissolve polystyrene by itself, more benzene must be added to it. If gasoline is inhaled or swallowed, it can be dangerous or fatal. Breathing it results in an intense burning sensation in the throat and lungs, resulting in bronchitis and, eventually, pneumonia and possibly death. Swallowing gasoline results in inebriation (drunkenness), vomiting, dizziness, fever, drowsiness, confusion, and cyanosis (blue color).

Benzene is a light, colorless, aromatic liquid made from a variety of raw materials, mostly crude oil and coal. In many ways it is similar to gasoline, of which it is a part. The major uses of benzene are in making plastics and other chemicals, not fuel, although it could be used as one. If benzene is breathed or swallowed, it causes throat irritation, rest lessens, excitement, depression, and, finally, convulsions, which can lead to death. A long exposure to benzene vapors (months or years) leads to bone marrow depression and in rare cases, leukemia.

Polystyrene is the white, tough plastic that is used to make cups, plates, and other tableware and food containers. In the pure state it is slightly heavier than water. It dissolves easily in acetone and benzene, but not in gasoline. It is not poisonous; if swallowed it passes unchanged through the digestive tract. But it is possible to choke on it. Heated polystyrene softens at about 185 F. At higher temperatures it turns back into styrene, the chemical from which it was made. Styrene has been tested as toxic to rats. In air, polystyrene melts and burns with a yellow, sooty flame. Styrene itself has a sharp, unpleasant smell that is easy to recognize.

MK 77 Mod 4

The last remnants of America's MK 77 Mod 4 napalm stockpile were stored at Fallbrook, and a state-of-the-art facility was built on base to help eliminate these weapons. The last filled napalm canister was destroyed in March 2001.

The MK-77 is a napalm canister munition. The MK77 familiy is an evolution of the incendiary bombs M-47 and M-74, used during the conflict in Korea and the war in Vietnam. Napalm is an incendiary mixture of benzene, gasoline and polystyrene. The Marine Corps dropped all of the approximately 500 MK-77s used in the Gulf War. They were delivered primarily by the AV-8 Harriers from relatively low altitudes. During Operation Desert Storm MK-77s were used to ignite the Iraqis oil-filled fire trenches, which were part of barriers constructed in southern Kuwait.

Beginning in 1973 the Department of the Navy (DoN) began placing Vietnam era napalm canisters in storage at the Weapons Support Facility, Fallbrook Detachment. The Detachment is located approximately 60 miles north of San Diego, CA. By 1978 all such canisters had been consolidated and placed at the Detachment for storage and maintenance. The stockpile consists of approximately 34,123 individually crated napalm canisters. The canisters are not fused nor do they contain ignition devices. Over time, some of the aluminum canisters have degraded which has resulted in leaks. On-going maintenance of the stockpile includes the identification and repair of leaking canisters, grounds maintenance, and air monitoring.

The Department of the Navy (DoN) undertook a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to remove and dispose of the napalm stockpile at the Fallbrook Detachment. The removal action is being taken to remove the potential for release of harmful levels of pollutants to the air which may result as the aluminum napalm canisters continue to degrade over time. Removal and disposal activities began in the Spring of 1998 and took approximately two years to complete. The removal process involved On-site Demilitarization & Separation: napalm canisters will be decrated, punched, drained and shredded to result in three waste streams, wood, napalm, and aluminum; Containerization and Manifesting: napalm will be containerized in 6000 gallon tankers, aluminum in 55 gallon drums, and wood in 40 cubic yard steel boxes.

All applicable state and federal manifesting procedures were followed; Transportation: was conducted in accordance with US Dept of Transportation regulations and will occur by truck from the Fallbrook Detachment to a Marine Corps Base Camp Pendleton railhead and then by rail to treatment facilities, and finally; Treatment and Disposal: treatment of the napalm and aluminum wastes occured at GNI, a Resource Conservation and Recovery Act (RCRA) Subtitle C permitted facility located in Deer Park, Texas. GNI blended the napalm into alternative fuel for use as a substitute fuel at various cement manufacturing facilities. Treatment of the aluminum occured by solvent cleaning. The clean aluminum was then sent to a commercial smelter for recycling. Disposal of the wood occured at a Resource Conservation and Recovery Act (RCRA) Subtitle D permitted co-generation facility located in Tulsa, Oklahoma, where it was burned to produce electricity and steam.

MK 77 Mod 5

In March 2003 the Pentagon denied a report in The Age that napalm had been used in an attack by US Navy planes on an Iraqi position at Safwan Hill in southern Iraq. A navy official in Washington, Lieutenant-Commander Danny Hernandez, said: "We don't even have that in our arsenal." The report was filed by Age correspondent Lindsay Murdoch, who was attached to units of the First US Marine Division.

The Mk 77 Mod 5 firebombs are incendiary devices with a function indentical to earlier Mk 77 napalm weapons. Instead of the gasoline and benzene fuel, the Mk 77 Mod 5 firebomb uses kerosene-based jet fuel, which has a smaller concentration of benzene. Prior to Operation Iraqi Freedom, hundreds of partially loaded Mk77 Mod5 firebombs were stored on pre-positioned ammunition ships overseas. Those ships were unloaded in Kuwait during the weeks preceding the war.

There was a report on Al-Jazeera on December, 14, 2001 that the US was using napalm at Tora Bora in Afghanistan. In response, General Tommy Franks said "We're not using -- we're not using the old napalm in Tora Bora."

The US Department of Defense denied the use of napalm during Operation Iraqi Freedom. A rebuttal letter from the US Depeartment of Defense had been in fact been sent to the Australian Sydney Morning Herald newspaper which had claimed that napalm had been used in Iraq.

An article by the San Diego Union Tribune revealed however, on August 5, 2003, that incendiary weapons were in fact used against Iraqi troops in the course of Operation Iraqi Freedom, as Marines were fighting their way to Baghdad. The denial by the US DOD was issued on the technical basis that the incendiaries used consisted primarily of kerosene-based jet fuel (which has a smaller concentration of benzene), rather than the traditional mixture of gasoline and benzene used for napalm, and that these therefore did not qualify as napalm.