• Also Known As:
  • Chemical Warfare
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What are chemical terrorism agents?

Chemical terrorism agents can be poisonous vapors, aerosols, liquids or solids that have toxic effects on people. These chemicals are usually manmade but can also naturally occur in the environment. Chemical exposures can be unintentional, such as an industrial accident, or intentional, as in the case of a terrorist attack. The early detection and correct identification of chemical agents is critical to enable effective treatment and to prevent additional exposures.

Chemical agents can be deadly, are easy to distribute, and are relatively inexpensive to produce. Terrorists actively seek these agents due to the tremendous psychological impact their real or perceived use can have on the public.

These agents have been used in war since the time of the ancient Greeks. However, they gained international attention during World War I as various chemical gases were extensively used against the enemy in opposing trenches. More recently, there has been a resurgence of use in such places as Syria and Iraq; in 2017 and 2018 nerve agents were used in foreign political assassinations.

Chemical terrorism agents can be coated onto everyday items or dispersed into the air as an aerosol as occurred in Japan. In 1994 and 1995, the terrorist cult Aum Shinrikyo released a crude form of sarin nerve gas into the air in two Japanese cities, which resulted in 19 deaths and over one thousand people injured. Most of the injuries were due to the panic that ensued after the attack.

Chemical agents normally cause a small number of deaths each year. They can enter the body by inhalation into the lungs, ingestion through food and water, absorption through the skin, or by contact with the mucous membranes of the eyes and nose.


About Chemical Terrorism Agents


The Centers for Disease Control and Prevention (CDC) identifies potential chemical terrorism agents according to type of chemical or by the effect it would have on people exposed to it. The table below identifies the major CDC categories and gives select examples of each group.

Category CDC General Definition Key Agent(s)
Biotoxins Poisons that come from plants or animals Nicotine, Digitalis, Ricin, Strychnine
Blister agents/Vesicants Chemicals that severely blister the eyes, respiratory tract, and skin on contact Mustard gas, Lewisite
Blood Agents Poisons that affect the body by being absorbed into the blood Carbon monoxide, Cyanide
Caustics (Acids) Chemicals that on contact burn or corrode a person’s skin, eyes, mucus membranes (lining of the nose, mouth, throat, and lungs) Hydrogen chloride, Hydrogen fluoride
Choking/Pulmonary Chemicals that cause severe irritation or swelling of the respiratory tract (lining of the nose, throat and lungs) Chlorine, Phosgene, Phosphorus
Incapacitating Drugs that make people unable to clearly think or that cause an altered state of consciousness or unconsciousness Opioids like fentanyl, BZ (3-Quinuclidinyl Benzilate)
Long-acting anticoagulants (blood thinners) Poisons that stop the blood from clotting, leading to uncontrolled bleeding Superwarfarin—an ingredient in rodent poisons
Metals (Heavy) Agents that consist of metallic poisons Arsenic, Mercury, Thallium
Nerve agents Highly poisonous chemicals that work by preventing the nervous system from working properly Novichok, Soman, Sarin, Tabun, VX
Riot control/Tear gas Highly irritating agents normally used by law enforcement for crowd control or by individuals for protection, like Mace CS (Chlorobenzylidenemalononitrile) tear gas, Chloropicrin
Toxic alcohols Poisonous alcohols that can damage the heart, kidneys, and nervous system Ethylene glycol, Methanol

For more information, visit the CDC’s web site. For information regarding the emergency preparedness and response plans the U.S. government has in place in the event of a chemical terrorist attack, see the CDC’s chemical emergencies web site.

In addition to chemical agents, biological and radioactive agents may also be used as weapons of terrorism. In 2001, highly purified anthrax bacterial spores were packaged into letters that were sent through the U.S. mail. This resulted in 5 deaths and 17 non-fatal infections. An example of a radioactive agent is polonium 210, which was listed as the cause of death of the Russian dissident Alexander Litvinenko in 2006. For more on these agents, see the CDC webpage Preparing for and Responding to Specific Hazards.


At present, there are no commercially available tests to broadly screen people who may have been exposed to a chemical terrorism agent, although testing is available through specific organizations. For example, if an individual appears to display signs and symptoms of a chemical agent, the CDC can conduct a Rapid Toxic Screen that can detect 150 chemical agents in blood and/or urine. Specific chemicals, like nerve agents or blister agents, once presumptively identified are then confirmed using more sophisticated technology. These lab results can identify which chemicals were used, exactly who was exposed, and estimate how much of a specific agent their bodies absorbed.

Select laboratories are currently equipped or are appropriately staffed to test for chemical terrorism agents. In 1999, the CDC, with the Federal Bureau of Investigation and the Association of Public Health Laboratories, established the Laboratory Response Network (LRN). This serves as an integrated national and international group of clinical, public health, environmental, food, water, veterinary, military, and agriculture laboratories that can respond quickly to chemical terrorism, bioterrorism, and other public health threats.

The LRN-C network specifically focuses on chemical agents and, as of August 2018, includes over fifty linked state and public health laboratories. These labs are divided into three levels based on the type of testing performed:

  • Level 1 labs: ten labs provide complete testing of chemical agents and are considered national resources since they serve as surge capacity for CDC (i.e., they can provide testing when there is a sudden increase in samples).
  • Level 2 labs: thirty-four labs provide testing for a number of chemical agents, including analysis of cyanide, nerve agents, and toxic metals in human samples.
  • Level 3 labs: nine labs maintain competency in clinical specimen collection and processing, storage and shipment of samples to appropriate Level 1 or Level 2 labs for testing.

The CDC oversees the production of standardized reagents, procedures, training, and a secure electronic communications system in the LRN-C. The U.S. Department of Defense can also provide support through such organizations at the Army Medical Research Institute of Chemical Defense as can the Organization for the Prevention of Chemical Weapons (OPCW). The latter organization includes the recognized international experts that confirmed the use of nerve agents to assassinate Kim Jong Nam in 2017 and the attempted assassination of a Russian dissident and his daughter in 2018.

The U.S. is well prepared to respond quickly to domestic chemical terrorism with established standardized tests to identify specific chemicals agents and their sources. Through planned coordination with local and state health departments, law enforcement, the CDC, and other major government agencies like the military, exposure to chemical agents can be rapidly identified, impacted areas isolated, and victims effectively treated.

View Sources

Author: Peter L. Platteborze, PhD, DABCC, FACB, Laboratory Director

Kyle B. Olson, Aum Shinrikyo: Once and Future Threat? Volume 5, Number 4—August 1999. Available online at https://wwwnc.cdc.gov/eid/article/5/4/99-0409_article. Accessed July 2018.

Gregory JA, Platteborze PL. (2015) Chemical Warfare Agents: a Century of Terror: Part 1- the Vesicants. Therapeutics and Toxins News. Available online at https://www.aacc.org/-/media/Files/Divisions/TDM-TOX/TDM_Newsletter_Winter_2015.pdf?la=en&hash=4DE7084C2B0C6767CA4CD2FB8CBA88B87F3F8874. Accessed July 2018.

Studer L, Ennis BA, Platteborze PL. (2016) Chemical Warfare Agents: a Century of Terror: Part 2- the Nerve Agents. Therapeutics and Toxins News. Available online at https://www.aacc.org/-/media/Files/Divisions/TDM-TOX/TDM-Newsletter-1601.pdf?la=en&hash=4906C5D196E7538C5309CAAE233EEBF4531B73F3. Accessed July 2018.

Platteborze PL. (2017). International Intrigue: Alleged VX Nerve Agent assassination. Available online at https://www.aacc.org/-/media/Files/Divisions/TDM-TOX/TDM-Newsletter-1704.pdf?la=en&hash=80029C645B114EF59A18E98011F99FB37BA0E779. Accessed July 2018.

Laboratory Response Network. Available pdf at https://www.aphl.org/aboutAPHL/publications/Documents/PHPR_LRNBrochure_52015.pdf. Accessed July 2018.

Kubin G, Klein DM. Available online at https://www.aphl.org/conferences/proceedings/Documents/2017/Annual-Meeting/41Kubin.pdf. Accessed July 2018.

Chemical Threats. Ready.gov. Available online at https://www.ready.gov/chemical. Accessed July 2018.

(April 4, 2018) Centers for Disease Control and Prevention. Chemical Emergencies. Available online at https://emergency.cdc.gov/chemical/index.asp. Accessed August 2018.

Available online at https://en.wikipedia.org/wiki/Chemical_warfare. Accessed July 2018.