History of U.S. Chemical Weapons Elimination

From World War I to 1968, the United States produced chemical weapons as a deterrent against use of similar weapons by other countries. Though never used in battle, these U.S. weapons are now obsolete and deteriorating with age. The U.S. national stockpile of lethal chemical warfare agents primarily involves six chemicals:

Nerve Agents

• GA - Tabun or ethyl N,N-dimethyl phosphoroamidocyanidate, CAS 77-81-6
• GB - Sarin or isopropyl methylphosphonofluoridate, CAS 107-44-8
• VX - O-ethyl-S-(2-diisopropylaminoethyl)-methyl phosphonothiolate, CAS 50782-69-9

Vesicant, or Blister Agents

• H, HD - Sulfur mustard, bis-(2-chloroethyl)sulfide, or di-2-chloroethyl sulfide (HD), CAS 505-60-2
• HT - bis(2-chloroethylthioethyl) ether (HT), CAS 63918-89-8
• L - Lewisite or dichloro 2-chlorovinylarsine, CAS 541-25-3

Congress Mandates Destruction of Outdated Chemical Weapons

From World War I to the early 1960s, the amount of chemical warfare agents stockpiled in the United States is thought to have reached nearly 40,000 tons. These chemical warfare agents were stored in bulk containers or as assembled weapons and ammunition at 9 sites in the United States.

During Operation Cut Holes and Sink ‘Em (CHASE) from 1967 to 1970, thousands of tons of unwanted chemical warfare agents and ammunition were disposed of by loading them onto old ships that then were intentionally sunk at sea. Eventually, environmental concern about dumping chemical weapons in the sea resulted in Congress passing Public Law (PL) 92-532 (33 USC 1401). Known as the Marine Protection, Research, and Sanctuaries Act of 1972, this law prohibits the kind of dumping done during Operation CHASE.

In 1970, Congress passed PL 91-121/441 (50 USC 1521). This law directed what is now the Department of Health and Human Services (HHS) and the Office of the Surgeon General (OSG) to review plans made by the Department of Defense (DoD) to transport, test or dispose of lethal chemical agents, and to recommend actions to protect the public’s health and safety during such activities.

HHS and OSG assigned responsibility for reviewing these DoD plans to the National Center for Environmental Health (NCEH) at the Centers for Disease Control and Prevention (CDC). Since 1983, NCEH’s Environmental Public Health Readiness Branch has reviewed plans of DoD’s Chemical Weapons Demilitarization Program. After these reviews, NCEH recommends actions to ensure that public health and safety are protected when chemical warfare agents are destroyed.

In 1986 as part of PL 99-145 (50 USC 1521), Congress required that all stockpiles of U.S. chemical warfare agents be destroyed. U.S. stockpiles totaled approximately 30,500 tons, according to the 1997 Organisation for the Prohibition of Chemical Weapons (OPCW) inventory. In addition, an estimated amount of non-stockpile chemical warfare items, such as recovered chemical weapons and chemical agent identification sets, existed at more than 200 sites in the United States and its territories.

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U.S. Signs International Chemical Weapons Convention Treaty

In 1997, the United States ratified the United Nations International Chemical Weapons Convention treaty. By participating in the treaty, the United States agreed to destroy its stockpile of aging chemical weapons—principally mustard agent and nerve agents—by April 29, 2007. However, the final destruction deadline was extended to April 29, 2012, at the Eleventh Session of the Conference of the States Parties to the Chemical Weapons Convention at The Hague on December 8, 2006.

The CDC chemical weapons elimination team’s mission is to protect public health and safety by providing oversight and guidance to the U.S. Army’s chemical warfare materiel demilitarization program by reviewing, advising, and making recommendations on the Army’s plans to destroy stockpile and nonstockpile chemical weapons. This mission is mandated by Public Laws 91-121, 91-441, and 99-145.

Today, the U.S. Army is recognized as a world leader in international chemical weapons elimination efforts. Over a decade of experience has demonstrated that these weapons can be destroyed safely, without harm to employees, to the community, or to the environment.

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Disposal of Stockpile and Nonstockpile Chemical Warfare Agents

Years ago, DoD stored chemical warfare agents, either in bulk containers or as assembled munitions, at locations within the continental United States. The remainder of the stockpile was transferred to Johnston Atoll, a small remote island in the Pacific Ocean (Southwest of the Hawaiian Islands). All chemical warfare agent materials previously stored on Johnston Atoll now have been destroyed.

Chemical warfare agents at two other sites (Aberdeen Chemical Agent Disposal Facility and Newport Chemical Agent Disposal Facility) have been destroyed and those sites are closed.

Disposal of all chemical warfare agents is complete at four other sites, and facilities are under construction at the two remaining sites. Read more about Closing U.S. Chemical Warfare Agent Disposal Facilities.

Nonstockpile chemical warfare materiel includes former chemical weapons production facilities; recovered chemical weapons, chemical samples, and binary chemical weapons; and miscellaneous equipment, such as empty aerial spray tanks.

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