Table 2: Characteristics of Chemical Warfare Agents¹

Click here to see the toxicity of chemical and biological agents.

Blister Agents   Agents that cause blisters on skin and damage the respiratory tract, mucous membranes, and eyes.
Name	Physical Characteristics	Persistency2	Commercial Uses of Chemicals or Precursor Chemicals3
Sulfur Mustard (HD)	Colorless to amber, oily liquid with odor of garlic	Persistent	Paper and rubber manufacturing, pharmaceuticals, insecticides, plastics, detergents, cosmetics, lubricants
Lewisite	Light amber liquid with odor of geraniums	Semi-persistent	Ceramics, insecticides, pharmaceuticals
Nitrogen Mustard (HN-3)4	Amber, odorless liquid	Persistent	Toiletries, insecticides, waxes, polishes, lubricants, cosmetics
Mustard- Lewisite (HL)	Liquid with garlic odor	Semi-persistent	Paper and rubber manufacturing, pharmaceuticals, insecticides, plastics, detergents, cosmetics, ceramics, lubricants
Phosgene oxime (CX)	Colorless liquid or crystalling solid with a disagreeable odor	Relatively non-persistent
Nerve Agents Lethal substances that disable enzymes responsible for the transmission of nerve impulses.
Name (Symbol)	Physical Characteristics	Persistency2	Commercial Uses of Chemicals or Precursor Chemicals3
Tabun (GA)	Brownish to colorless liquid with odor ranging from none to fruity	Persistent	Insecticides, gasoline additives, detergents, missile fuel, plastics, dyes, and pigments
Sarin (GB)	Colorless liquid with almost no odor	Non-persistent	Fire retardants, insecticides, disinfectants, paint solvents, ceramics, optical brighteners
Soman (GD)	Colorless liquid with fruity to camphor like odor	Semi-persistent	Fire retardants, paint solvents, ceramics, disinfectants, textile softeners
VX	Amber liquid with no odor	Persistent	Insecticides, pyrotechnics, textile softeners, pharmaceuticals
Novichok agents5	Unknown	Unknown	Fertilizers, pesticides
Choking Agents Substances that damage respiratory tract, causing extensive fluid build-up in the lungs.
Name (Symbol)	Physical Characteristics	Persistency2	Commercial Uses of Chemicals or Precursor Chemicals3
Chlorine	Colorless to slightly yellow with sharp, irritating odor	Non-persistent	Disinfectants, plastics, pesticides, solvents, chemical synthesis
Phosgene (CG)	Colorless gas with odor of freshly mown hay, or corn	Non-persistent	Plastics, pesticides, dyes, and herbicides
Diphosgene (DP)	Colorless liquid with odor of corn or freshly mown hay	Non-persistent	Plastics, pesticides, dyes, and herbicides
Chloropicrin (PS)	Oily, colorless liquid with pungent odor	Non-persistent	Disinfectant, chemical synthesis
Blood Agents Agents that interfere with the absorption of oxygen into the bloodstream.
Name (Symbol)	Physical Characteristics	Persistency2	Commercial Uses of Chemicals or Precursor Chemicals3
Hydrogen Cyanide (AC)	Colorless gas with odor of bitter almonds	Non-persistent	Pesticides, fumigating, electroplating, gold and silver extraction
Cyanogen Chloride (CK)	Colorless liquid with sharp, pungent odor	Non-persistent	Dyes and pigments, nylon production
Riot Control (Incapacitating) Agents6 Substances that rapidly produce temporary disabling effects.
Name (Symbol)	Physical Characteristics	Persistency2	Commercial Uses of Chemicals or Precursor Chemicals3
Tear Agent 2 (CN)	Colorless, gray solid with sharp, irritating, floral odor	Non-persistent	Commercially available as mace
Tear Agent O (CS)	White crystalline substance with pepper-like odor	Non-persistent
Psychedelic Agent 3 (BZ)	White crystalline solid with no odor	Non-persistent	Pharmaceuticals, tranquilizers

1. Sources: Central Intelligence Agency, The Chemical and Biological Warfare Threat (Washington, D.C.: Central Intelligence Agency, 1995); Office of Technology Assessment, Proliferation of Weapons of Mass Destruction: Assessing the Risks, OTA-ISC-559 (Washington, D.C.: Government Printing Office, 1993); Valerie Adams, Chemical Warfare, Chemical Disarmament (Indianapolis: Indiana University Press, 1990); Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare Volume I The Rise of CB Weapons (New York: Humanities Press, 1971); Chemical Weapons Convention Verification: Handbook on Scheduled Chemicals (August 1993); Gordon Burck and Charles Floweree, International Handbook on Chemical Weapons Proliferation ( New York: Greenwood Press, 1991); U.S. Army Center for Health Promotion and Medicine, Detailed Chemical Fact Sheets, Office to the Deputy for Technical Services, last updated 23 July 1998; Iraqi Weapons of Mass Destruction Programs (Washington, D.C.: Central Intelligence Agency, 13 February 1998); Edward M. Spiers, Chemical Warfare (Urbana: University of Illinois Press, 1986); Robert E. Boyle, U.S. Chemical Warfare: A Historical Perspective, (Albuquerque, N.M.: Sandia National Laboratories, August 1998)

2. Persistency refers to the length of time that contact and inhalation effects of an agent remain operative once disseminated. (Burck & Floweree)

3. Precursors are chemicals changed by reaction to make a chemical warfare agent.

4. In total, three nitrogen mustard agents were developed. The first, HN-1, explored in the late 1920s and early 1930s, was originally designed as a pharmaceutical product. HN-2 followed as a military agent, but later transitioned into the pharmeutical realm. HN-3 was the last of the nitrogen mustards to be developed. These charts focus on HN-3 because its formidable blistering capabilities approach those of sulfur mustard (HD).

5. For more information regarding novichok agents, refer to Vil Mirzayanov's "Dismantling the Soviet/Russian Chemical Weapons Complex: An Insider's View," Chemical Weapons Disarmament in Russia: Problems and Prospects (Washington, D.C.: Henry L. Stimson Center, 1995).

6. Riot control agents listed are a partial representation of existing incapacitating agents. Other agents currently stockpiled around the world for law enforcement purposes can cause vomiting and irritation of the skin, among other symptoms.