Chemical warfare agents are poisonous chemicals that can produce irritating effects, make materials or areas unusable, and cause death. The severity of the injuries depends on the type of agent, concentration of the agent used, and the method of dissemination.
Types of Chemical Agents
The United States Military classifies lethal chemical warfare agents into four categories:
Nerve Agents.Nerve agents attack the nervous system and affect muscle control, vision, heart, and lung functions. The Department of Defense (DOD) considers this the most likely category of chemical agents that may be used against U.S. Military personnel engaging in combat operations.
Blister Agents.Blister agents attack and destroy cell tissue causing irritation, inflammation, and severe blisters. This tissue damage increases the chance of infection and may ultimately cause death. In most cases, pain and blisters may not occur until long after exposure.
Choking Agents.Choking agents cause irritation and inflammation of the bronchial tubes and lungs. If a sufficient amount enters the lungs, liquid may gather there. Death results from lack of oxygen.
Blood Agents. Blood agents disrupt the oxygen-carrying properties of the blood. These fast-acting agents dissipate quickly in the open air but are very deadly. Blood agents also damage mask filters, so filters must be changed as soon as possible after a blood agent attack.
For detailed information about the primary chemical warfare agents threats, see our Chemical Warfare Agents Fact Sheets.
Delivery and Physical Properties
Chemical agents can be released by artillery shells, rockets, bombs, grenades, mines, aircraft sprays, and missiles. Additionally, they can be sprayed from air, land, and water vehicles or covertly used to contaminate food and water supplies. Common forms of chemical agents include:
Gases and Vapors. Gases and vapors are usually invisible. However, gas clouds may be visible for a short time after their release or in areas where there is little air movement to dissipate them. Their primary route of entry is through the respiratory tract, although some agents in heavy concentrations can penetrate the eyes and exposed skin. Gases and vapors may linger for up to several hours, with heaviest concentrations occurring in low-lying, dead air spaces such as buildings, caves, shell craters, ravines, and wooded areas.
Liquids. Liquid agents can be clear to dark in color and have the viscosity of fine machine oil; thickened agents may have the appearance of motor oil. Chemical agents used in liquid form can be extremely difficult to detect with the unaided eye. The most reliable method of both detecting and identifying liquid nerve and blister agents is M8 chemical detector paper. Finally, liquid agents also release toxic vapors that can be inhaled and can remain effective for many days.
Solids (Powders). Some agents are released in powder form. They can enter the body through the skin or be inhaled. Agents in dust-like form are released in a variety of climatic conditions and can remain effective for many weeks. These "dusty" agents are difficult to detect unless wetted. Once detected, they may be decontaminated with a 5 percent chlorine bleach solution.
Regardless of the type, concentration, or method of attack, the best immediate protection against chemical agents is the mask and chemical-defense ensemble. The United States Military has the best equipment fielded anywhere in the world, and when used correctly, it protects against enemy chemical or biological attack.
The mask is the primary piece of protective equipment. When properly worn, it protects the face, eyes, and respiratory tract against all known chemical and biological agents. In addition to the mask, the chemical-defense ensemble used by the United States Military include the chemical overgarment (pants and jacket), the mask-hood, protective gloves, and protective overboots.
Gas Mask.Gas masks are not new to the military. Military gas masks were first employed en masse during the First World War to protect soldiers from gas attacks. Toxic gases were seen as a way to bring an end to the stalemate on the Western Front. The predominant chemical agents used on the Western Front were mustard gas (blister agent) and chlorine gas (choking agent). From then until now gas masks have become as much a part of the military member's personal equipment as the rifle, flak vest and helmet.