Assembled chemical weapons are configured with fuzes, explosives, propellants, chemical agents, shipping and firing tubes and packaging materials. Examples include rockets and projectiles.

The U.S. Army Pueblo Chemical Depot originally stored 2,613 U.S. tons of the mustard agents in projectiles and mortar rounds. In Kentucky, the Blue Grass Army Depot originally stored 523 U.S. tons of both nerve and mustard agents in rockets and projectiles. Destruction of the remaining U.S. chemical weapons stockpile is occurring in both Colorado and Kentucky.

Mustard (blister) agent, purified sulfur mustard or distilled mustard, has a 5% sulfur impurity, less odor and greater blistering power than the original mustard agent used in World War I. Mustard agent is also known as H, HD or HT. Exposure to mustard agent causes inflammation of the eyes, nose, throat, trachea, bronchi and lung tissue, and blisters the skin. In amounts approaching the lethal dose, injury to bone marrow, lymph nodes and spleen may occur. Mustard agent is toxic and the International Agency for Research on Cancer has deemed it a carcinogen (cancer-causing agent).

To learn more, visit the Facts: Characteristics of Mustard (Blister) Agents page.

There are two types of nerve agents currently stored in the U.S. chemical weapons stockpile: VX and GB. Nerve agent VX, a clear, odorless and tasteless liquid, has an appearance similar to motor oil. VX can become an aerosol (very small droplets) through explosion or a vapor through ignition. It is heavier than water and evaporates 2,000 times more slowly. Highly toxic in its liquid, aerosol and vapor forms, VX is the most hazardous when absorbed through the skin.

Nerve agent GB, also known as sarin, is one of the most toxic members of the organophosphate family. Under normal conditions, it is a clear to straw-colored liquid and has approximately the same density and evaporation rate as water. GB presents the greatest hazard when released in vapor form. Such vapors can be released only by evaporation of the liquid or vaporization into the air.

To learn more, visit the Facts: Characteristics of Nerve Agents page.

Pueblo Chemical Agent-Destruction Pilot Plant, or PCAPP, is a state-of-the-art facility that is safely destroying the remaining U.S. chemical weapons stockpile at the U.S. Army Pueblo Chemical Depot, or PCD, in Pueblo, Colorado. The stockpile of chemical weapons originally stored at PCD are 155mm projectiles, 105mm projectiles and 4.2-inch mortar rounds. PCAPP is using neutralization followed by biotreatment to destroy the remaining stockpile in the main plant. The Explosive Destruction System, an explosive destruction technology, was used to destroy problematic chemical munitions from 2015 to 2018. Static Detonation Chamber technology was selected to augment main plant operations and destroy problematic mustard chemical agent-filled projectiles and 4.2-inch mortar rounds.

The Blue Grass Chemical Agent-Destruction Pilot Plant, or BGCAPP, is a state-of-the-art facility that is safely destroying the remaining U.S. chemical weapons stockpile at the Blue Grass Army Depot near Richmond, Kentucky. The depot stored three types of chemical weapons in the original stockpile in Kentucky: 155mm projectiles, 8-in. projectiles and M55 rockets. The BGCAPP main plant is using neutralization to destroy the nerve agent stockpile. Meanwhile, the site’s explosive destruction technology, the Static Detonation Chamber, was selected to destroy the entire mustard agent stockpile, as well as two 3-gallon Department of Transportation bottles containing mustard agent. Static Detonation Chamber technology is being used to process containerized, drained rocket warheads and overpacked munitions to augment main plant destruction in Kentucky.

To learn more, visit the BGCAPP Project Stages page and the Facts: Chemical Weapons Destruction at Blue Grass page.

The Pueblo Chemical Agent-Destruction Pilot Plant is in the operations phase and has completed two of three munitions destruction campaigns in the main plant. Static Detonation Chamber, or SDC, technology is currently in use to destroy 4.2-inch mortar rounds and other problematic mustard agent-filled munitions from the stockpile in Colorado. ACWA is targeting completion of its mission by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023. U.S. Public Law mandates stockpile destruction by Dec. 31, 2023.

 To learn more, visit the PCAPP Project Stages page and the Facts: Chemical Weapons Destruction at the U.S. Army Pueblo Chemical Depot page.

The Blue Grass Chemical Agent-Destruction Pilot Plant, or BGCAPP, is in the operations phase and has completed four of five munitions destruction campaigns. The plant is currently destroying GB nerve agent M55 rockets as part of the site’s fifth and final campaign. The Explosive Destruction Technology, which completed destruction of all the mustard agent-filled munitions in the stockpile in Kentucky, is being converted to the Static Detonation Chamber, or SDC 1200, to destroy containerized, drained VX rocket warheads. The SDC 2000, used for processing containerized, drained and undrained GB rocket warheads and overpacked munitions, is in operations. ACWA is targeting completion of its mission by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023. U.S. Public Law mandates stockpile destruction by Dec. 31, 2023.

 To learn more, visit the BGCAPP Project Stages page and Facts: Chemical Weapons Destruction at Blue Grass page.

Neutralization followed by biotreatment

Neutralization followed by biotreatment uses hot water to neutralize the chemical agent, effectively destroying the mustard agent molecules. The resulting product, hydrolysate, is mostly water and thiodiglycol, a common industrial chemical that is readily biodegradable. Ordinary sewage treatment bacteria, or microbes, consume the organics in the hydrolysate. Besides being a common phenomenon in nature, the science of using microbes to help dispose of hazardous waste has existed for decades. Sewage treatment facilities across the country use microbes every day to help break down raw sewage.

To learn more, visit the Neutralization Followed by Biotreatment page.

Explosive Destruction Technology

The Static Detonation Chamber, an explosive destruction technology, was selected to augment the baseline technology to destroy 4.2-inch mortar rounds and problematic chemical munitions that cannot be easily processed through the main plant. The SDC uses thermal destruction technology to process the weapons. Chemical munitions are placed in a feed box, conveyed to the top of the SDC vessel and fed into the electrically heated detonation chamber. The high heat (approximately 1,100 degrees Fahrenheit) detonates the munition, and the chemical agents and energetics are destroyed by thermal decomposition. Gases generated as a result of the process are treated by an off-gas treatment system that includes a thermal oxidizer, scrubbers and a carbon filtered system. All waste streams generated are screened and remaining scrap metal is decontaminated to be recycled.

Watch the following video to learn more about how the SDC works:

Neutralization

During the neutralization process, munitions are taken apart and the chemical agent is the mixed vigorously with hot water and sodium hydroxide, which destroys or neutralizes the agent. The resulting product, known as hydrolysate, is held and tested to ensure agent destruction before being shipped to an off-site treatment, storage and disposal facility for processing.

To learn more, visit the Facts: Neutralization page.

Static Detonation Chamber

Static Detonation Chamber technology was selected to augment the neutralization process to destroy the entire mustard stockpile in Kentucky, many of which have been found unsuited for processing through the main plant. Static Detonation Chamber units were also selected to augment the main plant in destroying containerized, drained rocket warheads and overpacked munitions from the stockpile.

Explosive Destruction Technologies, are used to supplement destruction at the main plants, and use explosive charges or heat to destroy chemical weapons. They do not require disassembly of the munitions. There are three general types of explosive destruction technologies that can destroy chemical weapons: detonation technology, neutralization technology and thermal destruction.

In Colorado, Static Detonation Chamber, or SDC, technology was selected to destroy the 4.2-inch mortar rounds and problematic munitions unsuited for processing through main plant operations at the Pueblo plant. In February 2022, the three SDC units began operations. Previously, from 2015 to 2018, the Pueblo plant used the U.S. Army’s Explosive Destruction System to destroy problematic munitions.

In Kentucky, SDC technology was selected to destroy all of the mustard projectiles, as well as two 3-gallon Department of Transportation bottles containing mustard agent. Static Detonation Chamber units were also selected to process containerized, drained rocket warheads and overpacked munitions from the stockpile to augment main plant destruction in Kentucky.

The Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP) and Blue Grass Chemical Agent-Destruction Pilot Plant (BGCAPP) comply with a number of safety standards set forth by the Department of Defense, U.S. Army, Army Materiel Command, Centers for Disease Control and Prevention and more. Additionally, each site has been recognized as an Occupational Safety and Health Administration Voluntary Protection Programs , or VPP, Star Status. The VPP recognizes employers and workers in the private industry and federal agencies who have implemented effective safety and health management systems and maintain injury and illness rates below national Bureau of Labor Statistics averages for their respective industries.

The Pueblo Chemical Agent-Destruction Pilot Plant and Blue Grass Chemical Agent-Destruction Pilot Plant must adhere to the Resource Conservation and Recovery Act, which gives the U.S. Environmental Protection Agency authority to control hazardous waste, including generation, transportation, treatment, storage and disposal of hazardous waste to protect human health and the environment. Furthermore, both plants comply with all permit regulations in accordance with the state of Colorado and the Commonwealth of Kentucky.

To learn more, visit the Environmental Activities at PCAPP and Environmental Activities at BGCAPP pages.

With its available Static Detonation Chamber, the Anniston Field Office, or AFO, allowed Blue Grass and Pueblo operators to be effectively trained while the Blue Grass and Pueblo plant’s Static Detonation Chamber units were being installed and tested, saving both time and money. AFO is also handling the disposition of the Pueblo plant’s non-contaminated explosive components of some 780,000 artillery and mortar rounds and non-contaminated rocket motors from the Blue Grass plant.

To learn more, visit the Facts: Anniston Field Office page.

As a signatory to the Chemical Weapons Convention, the U.S. must destroy all chemical weapons it owns or possesses. The U.S. Army Chemical Materials Activity (formerly known as the Chemical Materials Agency) destroyed nearly 90% of the original chemical weapons stockpile. PEO ACWA is actively destroying the remaining 10% of the nation’s chemical weapons stockpile and is targeting completion of its mission by the Chemical Weapons Convention treaty commitment of Sept. 30, 2023. U.S. Public Law mandates stockpile destruction by Dec. 31, 2023.

For the latest chemical agent destruction statistics in Colorado, visit the PCAPP homepage. For the latest chemical agent destruction statistics in Kentucky, visit the BGCAPP homepage.