(2) Vapors and droplets of liquids can be absorbed from the surface of the skin and mucous membranes. Toxic compounds that are harmful to the skin can produce their effects in liquid or solid state. Agents penetrating the skin may form temporary reservoirs under the skin; the vapors of some volatile liquids can penetrate the skin and cause intoxication. Additionally, wounds and abrasions may present areas that are more permeable than intact skin.
b. Chemical agents may be divided into two main categories (persistent and nonpersistent) that describe how long they are capable of producing casualties. [Table A-12] lists the common chemical agents, their effects and time of effectiveness. [Table A-13] lists the types and characteristics of common chemical agents.
(1) Persistent agents continue to present a hazard for considerable periods (days) after delivery by remaining as a contact hazard, or by slowly vaporizing to produce a hazard by inhalation.
(2) Nonpersistent agents disperse rapidly after release and present an immediate, short duration (hours) hazard. They are released as airborne particles, aerosols, and gases.
Table A-12. Common Chemical Warfare Agents
| COMMON NAME | EFFECT | TIME TO EFFECT |
|---|---|---|
| TABUN (GA) | LETHAL NERVE AGENTS | INHALATION: SECONDS TO MINUTES TOPICAL: MINUTES INGESTION: MINUTES TO HOURS |
| SARIN (GB) | ||
| SOMAN (GD) | ||
| V-AGENTS | ||
| HYDROGEN CYANIDE | LETHAL BLOOD AGENT | MINUTES |
| MUSTARD | BLISTER AGENTS | 1 TO 12 MINUTES |
| LEWISITE | MINUTES | |
| LSD AND BZ | INCAPACITATING AGENTS | 15 TO 60 MINUTES |
| PHOSGENE | LUNG-DAMAGING (CHOKING) | MINUTES |
| CHLORINE | SECONDS TO MINUTES | |
Table A-13. Types and Characteristics of Chemical Agents
| TYPE OF AGENT | SYMBOL | PERSISTENCE | RATE OF ACTION | ENTRANCE | ||
|---|---|---|---|---|---|---|
| SUMMER | WINTER | VAPOR/AEROSOL | LIQUID | |||
| NERVE | GA, GB, GD | 10 MIN-24 HR | 2 HR-3 DAYS | VERY QUICK | EYES, LUNGS | EYES, SKIN, MOUTH |
| VX | 2 DAYS-1 WK | 2 DAYS-WEEKS | QUICK | EYES, LUNGS | EYES, SKIN, MOUTH | |
| CHOKING | CG, DP | 1-10 MIN | 10 MIN-1 HR | IMMEDIATE | LUNGS | EYES |
| BLISTER | HD, HN | 3 DAYS-1 WK | WEEKS | SLOW | EYES, SKIN, LUNGS | EYES, SKIN |
| L, HL | 1-3 DAYS | WEEKS | QUICK | EYES, SKIN, LUNGS | EYES, SKIN, MOUTH | |
| CX | DAYS | DAYS | VERY QUICK | EYES, LUNGS, SKIN | EYES, SKIN, MOUTH | |
| BLOOD | AC, CK | 1-10 MIN | 10 MIN-1 HR | VERY QUICK | EYES, LUNGS | EYES, MOUTH, INJURED SKIN |
A-13. Characteristics of Chemical Agents
The effectiveness of a chemical agent is a measure of how much agent is required to produce the desired effect. Thus, an agent that is toxic at a lower dose than another similar agent is more effective. Besides dose required for a given effect, persistency may be used to measure effectiveness. Persistency depends on the agent's physical characteristics, the amount of agent delivered, its physical state, weapons system used, the terrain, and weather in the target area. The desired effects will determine the physical, chemical, and toxicological properties of the chemical agent employed.