CHEMICAL OPERATIONS

In chemical operations, death, injury, or irritating effects are produced by toxic chemical agents. Although chemical agents are frequently referred to as gases, they may actually be found as solid particles, liquids, or gases. Chemical agents are used chiefly for their effects on personnel. Some agents have corrosive effects on certain materials, and incendiary agents will burn most materials. Chemical agents produce harmful physiological reactions when applied to the body externally, inhaled, or swallowed. Most military chemical agents cause disorganization of the functioning of the body.

Chemical agents can be disseminated by aircraft spray, chemical projectiles, chemical bombs, chemical grenades, smoke pots, smoke candles, chemical land mines, and missiles. These principal factors determine the method by which a chemical agent is spread, the quantity of the agent required to accomplish specific objectives, the nature of the agent being used, the distance to the place of attack, and the speed with which the agent must be used.

CHARACTERISTICS AND EFFECTS OF CHEMICAL AGENTS

A few of the general physiological effects of the more common chemical agents are discussed here and are listed in table 9-1. More detailed physiological effects of the different groups of agents are discussed later.

The rate of action of a chemical agent is the rate at which a body reacts to or is affected by that agent. There is a wide variation in the rate of reaction to the toxic chemical agents, even to those of similar tactical or physiological classifications. For example, distilled mustard (HD) produces no immediate sensation, and 4 to 6 hours may pass before the skin reddens. Lewisite (L), on the other hand, causes immediate pain, and the skin begins to redden within 30 minutes.

Blister agents must be decontaminated within 1 to 2 minutes after exposure if serious effects are to be prevented. Nerve agents and blood agents act quickly. If death is to be averted, you should administer antidotes or start other first aid measures within 30 seconds after the beginning of symptoms. Vomiting and tear agents also take effect within a short time after being inhaled.

Some agents are effective when absorbed through the skin or eyes, but others must be inhaled. Tear agent CN primarily affects the eyes; tear agent CS affects both the eyes and the upper respiratory tract. Blister agents affect the internal as well as the external body surfaces. Nerve agents can attack the body through contact with the skin and eyes and through inhalation. Vomiting agent adamsite (DM) and choking agent phosgene (CG) must enter the lungs to produce their effects.

The rate of detoxification is the rate at which the body counteracts the effects of a chemical agent. It is an important factor in determining the hazards of repeated exposure to sublethal doses of toxic chemical agents. Some agents are detoxified quite rapidly. Other agents are detoxified very slowly, and their effects are cumulative. The blood agents cyanogen chloride (CK) and

Table 9-1.-Properties of Chemical Agents Page 9-7.

Table 9-1.-Properties of Chemical Agents-Continued page 9-8

hydrogen cyanide (AC) are detoxified rapidly, thus requiring high concentration for maximum casualties. The nerve agent sarin (GB) is detoxified slowly and is cumulative to a large degree. If 50% of a lethal dose is received, only minor symptoms appear. However, another 50% received within the next few hours may cause death if no treatment is received. The blister agent distilled mustard (HD) and the choking agent phosgene (CG) also are cumulative. A 10-minute exposure to either followed a few hours later by a similar exposure has the same effect as one 20-minute exposure. Additionally, repeated exposure to sublethal doses of HD can result in sensitivity to low concentrations of the agent.