fm 3-9 potential military chemical and biological agents and compounds (1990) ww

8/7/2019 fm 3-9 potential military chemical and biological agents and compounds (1990) ww

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Army Field Manual No 3-9

Navy Publication No P-467

Air Force Manual No 355-7

Potential Military Chemical/Biological Agents and

Compounds

Headquarters

Department of the Army

Department of the Navy

Department of the Air Force

Washington, DC, 12 December 1990 PCN 320 008457 00


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P r e f a c e

This field manual provides commanders andstaffs with general information and technicalda ta concerning chemical and biologicalagents and other compoun ds of m ilitary inter-est. It discusses the use; the classification; and

the p hysical, chemical, and physiologicalproperties of these agents and comp ound s. Italso discusses protection and decontaminationof these agents. In addition, it discusses theirsymptoms and the treatment of thosesymptoms.

The proponent of this publication is Head-quarters, TRADOC. Subm it recomm end edchanges for imp roving this pu blication on DAForm 2028 (Recommended Changes to Publi-cations and Blank Forms) and forward it to

Command ant, US Army Chem ical School,ATTN: ATZN-CM-NF, Fort McClellan, AL36205-5020. Send applicable Air Force com-ments by letter to HQ, USAF/ XOOTM,Washington, DC 20330-5054.

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*FM 3-9 NAVFAC P-467 AFR 355-7

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United States Policy

Biological Agents No Use1. The Un ited States will n ot use biological agents, includ ing toxins

and all other m ethod s of biological warfare, un der any circum stances.2. The Un ited States will strictly limit biological research to defensive

measures.

Chemical Agents No First Use1. US armed forces will n ot use leth al or incapacitating chemical

agents first.2. The Un ited States w ill strictly reserve the righ t to retaliate, usin g

lethal or incapacitating chemical agents, against an enemy force that

has used them on US forces.3. The au thority to ord er or app rove the first retaliatory chem icalstrike rests with the p resident of the United States.

4. The Un ited States will avoid risk to civilian p opu lations to themaximu m extent p ossible.


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Chapter 1

I n t r o d u c t i o n

Nations have used toxic chemical agents in the past, and w e cannot ignore the

possibility that they will use them in future conflicts. An u nd erstand ing of chemical

and biological agents and other compou nd s of military interest is vital to our ability

to cope with their possible use against our forces. To develop an u nd erstand ing of

chemical and biological agents and other compou nd s of military interest, you m ust

learn abou t several factors. You m ust learn about their historical use, the US

policy regard ing their use, and th e properties that cause a substance to be suitable

for use in military operations.

Section I. Background and Policy

Background

Chemical and biological (CB) operations are not new.Historical records show previous use of chemicals, smoke,and flame in warfare. In World War I the Allies and theGermans used them extensively. Many nations developedand manufactured agents during World War II, and somehave used these agents since then.

As with chemicals, crude forms of biological warfarestarted in ancient times. Poisoning of water supplies with

rotting carcasses was common practice. In the 1300s theTartars catapulted corpses of plague victims over the wallsand into the besieged city of Kaffa. History suggests thatfleeing survivors of this siege caused the black death, aplague epidemic that swept Europe. Pizarro in the 1500sand the British in the 1700s introduced smallpox amongIndians in the Americas as a means to win a war.

Documentation exists of more recent use of chemicaagents and some biological agents in AfghanistanSoutheast Asia, and Southwest Asia.

After World War I various international accords recognized the potential for chemical and biological weaponand outlawed these weapons. Most nations, including thSoviet Union, signed these treaties. However, recenevidence indicates some nations have not adhered to thes

bans. A growing number of nations can employ biologicaand chemical, as well as conventional, munitions.In addition to CB agents, related materials, such a

irritants and herbicides, lend themselves to modern warfare. The United States must prepare to defend againsthese weapons and materials and to retaliate when appropriate. The next paragraph further discusses US policon the use of these weapons.

United States Policy

The United States seeks to achieve a ver ifiable,world wide ban on chemical weapons. Until a verifiable ban

is achieved, the US policy is to d eter enemy chemicalweapons use through denying the enemy a significantmilitary advantage for such use. US chemical weaponsdeterrence includes a viable NBC defense capability and acredible retaliatory capability.

The United States will not use chemical weapons firstagainst an enemy but reserves the right to retaliate shouldan enemy use chemical weapons against US or Allied

forces. Only the president m ay ord er chemical weaponretaliation.

Current US policy states that we will not use herbicidein war, un less our ad versaries first employ them and thpresident directs their use in retaliation. Executive Orde11850 unilaterally renou nces first use of herbicides in warexcept to control vegetation within US bases and installations or around their immediate defensive perimeters.

The United States renounces the first use of riot controagents (RCAs) in war except in defensive military modeto save lives, such as in


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Riot control situations in areas un der d irect and dis-tinct US military control. This includes the control ofrioting p risoners of war.Situations in which civilians are used to mask or screenattacks, and these agents can reduce or avoid civiliancasualties.Rescue missions in remote or isolated areas. Examples

are recovering down ed aircrews and p assengers andrescuing escaping p risoners of war.Rear-echelon areas outside the zone of immediatecombat to protect convoys from civil disturbances, ter-rorists, and paramilitary operations.Security operations regard ing the protection orrecovery of nuclear w eapons.

The president must approve the use of riot controlagents in war.

The United States will not use biological agents, includ-ing toxins, regardless of source or mann er of prod uction,or other m ethods of biological war fare und er any cir-cumstances. The United States will strictly limit its biologi-cal and toxin research program to defensive measures, such

as production of vaccines, antidotes, treatment, andprotective equipment. US policy is in accordance with the1925 Geneva Pr otocol and the 1972 Biological Weap onsConvention, both of which the United States has signed andratified.

Section II . Militarily Significant Aspects of Chemical Agents

Classification of Chemical Agents and Miscellaneous Compounds

We classify chemical agents and compounds accordingto physical state, physiological action, and use. The termspersistent and nonp ersistent d escribe the time chemicalagents remain in an area. These terms do not classify theseagents technically. We define chemical agents apart frommilitary chemical comp ound s. Chemical agent u se kills,seriously injures, or incapacitates people. These agentsinclude blood, nerve, choking, blister, and incapacitatingagents. On the other hand, military chemical compoundsare less toxic. Military chemical compounds include riotcontrol agents, herbicides, smoke, and flame materials.The term excludes chemical agents.

Physical StateChemical agents and military chemical compou nd s mayexist as solids, liquids, or gases. To a certain extent the statein which an agent normally exists determines its use, dura-tion of effectiveness, and physiological action. It also deter-mines the type of mu nition used for its dissemination.

Physiological ActionWe classify agents and compounds by their physiological

actions as follows:

Choking AgentsChoking agents attack lung tissue, primarily causing pul-

mon ary edema (dry land d rown ing). These chemicalagents irritate and inflame tissues from th e nose to thelungs, causing a choking sensation.

Nerve AgentsThese chemical agents, when inhaled, ingested, or ab-

sorbed into the body through the skin, inhibitcholinesterase enzymes throughout the body. This inhibi-

tion perm its acetylcholine, which tran smits many nerveimpulses, to collect at its various sites of action. The majoreffects are

Muscle stimu lation w ith un coordinated contractions,followed by fatigue an d eventual paralysis.Pinpointed p up ils; tightness in chest; nausea, vomiting,and diarrhea; and secretions from the nose, mouth, andair passages.Disturbances in thought, convulsions, coma, anddep ression of vital centers of the brain, leading todeath.

Blood Agents

The body absorbs these chemical agents, including thecyanide group, primarily by breathing. They poison anenzyme called cytochrome oxidase, blocking the use ofoxygen in every cell in the body. Thus, these agents preventthe normal transfer of oxygen from the blood to bodytissues. The lack of oxygen rapidly affects all body tissues,especially the central nervous system.

Blister Agents (Vesicants)Both exterior and interior parts of the body readily

absorb these chemical agents. These agents cause inflam-mation, blisters, and general destruction of tissues. Agentvapors attack m oist tissue. Vulnerable areas include th e

eyes, mucous membranes, and respiratory tract. Eyes arevery susceptible to blister agent.

Tear Agen ts (Lacrimators)These compou nd s cause a large flow of tears and irrita-

tion of the skin. Some of these compou nds are very irritat-ing to the respiratory tract. They sometimes cause nauseaand vomiting.

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Vomiting Agents (Sternutators)These compou nds cause nausea and vomiting. They also

cause coughing, sneezing, pain in the nose and throat, nasaldischarge, or tears. A headache may follow.

DefoliantsThese compounds cause trees, shrubs, and other plants

to shed their leaves prematurely.

Plant Growth RegulatorsThese compounds regulate (stimulate or inhibit) plant

growth.

DesiccantsThese compound s remove w ater from p lant tissues,

causing the plants to dry and shrivel.

Soil SterilantsThese compou nds make a soil incapable of supp orting

higher p lant life. Their effects may last one growing seasonor many years.

UseChemical agents and military chemical compounds may

be grouped according to use.

Chemical AgentsChemical agents may be either toxic or incapacitating.Toxic agents. Toxic agents can produce incapacitation,

serious injury, or death when used in field concentrations.

This category includes lethal and damaging (blister)agents. Lethal chemical agents in field concentrations canproduce death.

Incapacitating agents. Incapacitating agents prod ucetemporary physiological or mental effects, or both. Effectmay p ersist for hou rs or d ays after exposure. They maymake individuals unable to perform their assigned dutiesVictims d o not usu ally require medical treatment, buttreatment speeds recovery.

Military Chemical CompoundsThese comp ound s include riot control agents, training

agents and compounds, smokes, and herbicides.Riot control agents (RCAs) produce transient irritating

or d isabling effects. These effects disappear w ithin minuteafter exposure ends. Governments widely use these compound s for d omestic law enforcement pu rposes.

Training agents and compounds are chemicals that areauthorized for use in training. These chemicals enhanceproficiency for operating in an NBC environment.

Smokes are used for obscuring, screening, deceivingand identifying and signaling.

Herb icides are chemical comp oun ds th at w ill kill odamage plants.

Note: This manu al seeks to show only the generalrelationship between chemical agent properties anduses. FM 3-10-1, FM 3-11, FM 3-50, and FM 20-33specifically cover use concepts.

Duration of Effectiveness of Chemical Agents

Several factors determ ine the time a chemical agentremains effective. These include the method of dissemina-tion and the physical properties of the agent. Factors alsoinclude weather, terrain, and target conditions.

Method of DisseminationThe size of the particles disseminated greatly influences

the effectiveness of liquid or solid agen ts. Vapors oraerosols (air-contaminating agents) do not persist as longas do drop lets of agents used to contaminate terrain andmateriel. In explosive munitions the degree of divisiondepends upon several factors. These factors are the

amount and the type of burster charge and the fuzing of themunition (air or ground burst). Nonexploding types ofmunitions, such as aerosol generators and spray tanks, canvary the degree of dispersion. Thus, these types influencethe duration of effectiveness of agents.

Physical Properties of the AgentVapor pressure and volatility influence the rate of

evaporation. These properties are especially important in

determ ining the d ur ation of effectiveness of an agen tGases (vapors), aerosols, and highly volatile liquids tend todisperse rapidly after release. Thus, they present an immediate short-du ration h azard. Large drops or splasheremain a hazard longer than finely divided particles. Alsoviscous m aterials tend to ad here and not spread or flowreadily. This can increase persistency. Appendix A discusses physical properties.

Weather ConditionsMany weather factors influence the duration of effec

tiveness. The m ost important are temperature, tempera

ture grad ient, wind speed, relative humidity, andprecipitation. See FM 3-6 for a detailed d iscussion of theimpact of weather on duration.

TemperatureThe higher the ground or surface temperature, the

quicker a liquid chemical agent will evaporate from it. Lowtemperatures may freeze some agents, thus reducing thimmediate contact hazard, but will increase persistency.


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Temperature GradientOften the temp eratur e of the layer of air next to the

ground is different to that of the air layers above. This givesrise to a temperature grad ient. Agents in a vapor state w illremain near th e ground du ring stable (inversion) condi-tions. When an unstable (lapse) condition exists, air layersmix and agents d isperse more quickly.

Wind SpeedHigh wind s increase the rate of evaporation of liquid

chemical agents. High wind s also d isperse chemical cloud smore rapidly than low winds. A low wind speed allowsagent to persist longer. Also, the rate of spread will be slow.Vapors and aerosols disperse rapidly in open county;dangerou s concentrations may rem ain longer in w oods,foxholes, and built-up areas.

Relative Hu midityRelative humidity has little direct effect on most chemi-

cal agents. However, the choking agent p hosgene (CG) and

the blister agent lewisite (L) rapidly decompose at relativehumidities over 70 percent.

PrecipitationHeavy or lasting rains will wash liquid agent contamina-

tion to low areas and stream beds and present a lingeringhazard. Light rainfall can cause recurrence of a contacthazard. Snow tends to wash agents from the air. Snow coverreduces the vapor concentration above the contaminated

area but, in combination with the lower temp eratures,increases the duration.

Conditions of Terrain or TargetVegetation, soil, and contours play an important p art in

the duration of effectiveness of an agent at the target. SeeFM 3-6 for a detailed discussion of terrain impact.

VegetationLiquid chemical agents cling to vegetation, increasing

the area for contact and evaporation. Because of low windspeeds and reduced temperatures, heavily wooded andjungle areas retain vapors longer.

SoilToxic liquids qu ickly soak into p orous surfaces and

evaporate more slowly than from nonp orous surfaces. Thisincreases the duration of any vapor hazard, although itreduces vapor cloud concentration.

ContoursToxic clouds follow th e contour of the su rface of the

terrain. Chemical cloud s tend to go arou nd obstacles, suchas hills. Concentrations persist in h ollows, low gr ound ,depr essions, foxholes, and bu ildings. Rough ground , in-cluding that covered with tall grass or brush, slows chemicalcloud movement. Flat country (unless covered w ith tallgrass or brush) allows an even, steady movement. Urbanareas form local heat islands that may alter significantlythe normal temperature gradient.

Requisites and Desirable Features of Chemical Agents

The combined physical, chemical, and toxicological Capable of being handled and transported withoutproperties of a substance determine its suitability and ef- extensive precautions.festiveness as a chemical agent. These factors influencewh ether the substance meets the requisite and desirable Desirable Add itional Featuresfeatures of a chemical agent. A chemical agent should

Have little or no corrosive action on the m unition orRequisites container during storage.

A chemical agent mu st be Have su ch inherent prop erties that complete protec-Toxic. Through its chemical properties in small con- tion from the chem ical agent is difficult for enem ycentrations it w ill produ ce damaging or lethal effects personnel. If possible, the agent should be capable ofon man , animals, or plants. minimizing the effectiveness of the protective equip-Stable or capable of stabilization du ring the period ment of potential enemies.between its production and use. Hav e a know n ph ysiological mechanism of action,Produ cible from readily available raw materials in ade- protective measures, and a method of medical treat-qua te quantities for effective milita ry use. ment or p rophylaxis.Capable of dissemination from a device feasible for Be difficult to detect by ordinary methods before thefield u se in sufficient concentration to p rodu ce the onset of physiological and/ or psychological effects.desired effect on the target. (Colorless, odor less, and non irritating toxic chem ical

agents are desirable.)

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Physical Properties

The physical properties impact on how a chemical agentor compound is used. These properties also impact uponthe defensive measures against its use. Some of the moreimportant physical properties are vapor density, vaporpressure, volatility, melting and freezing points, and liquid

and solid densities. The vapor density determines whetherthe agent is lighter or heavier than air; it thus determineswhether the agent will settle to low areas or float away anddissipate in the atm osphere. Vapor pressure d etermines

the volatility and the rate of evaporation of an agent. Thrate of evaporation has a major effect upon the vapoconcentration. It also affects the duration of an agenhazard after dissemination. The boiling and freezing poinof chemical agents influence their operational use and th

means of disseminating them. See Append ix A for a d icussion of physical properties. Appendix B tabulatechemical agent physical properties and other data.

Chemical Properties

The chemical properties of an agent influence itsstability, toxicity, and reactivity with water and other sub-stances.

HydrolysisHydrolysis is the reaction of a compound with the ele-

ments of water w hereby d ecomp osition of the substanceoccurs. The reaction prod uces one or m ore new substan-ces.

Rapid hydrolysis aids in lowering the duration of effec-tiveness of toxic chemical agents. For examp le, in th epresence of water or water vapor, lewisite (L) rapidlyhydrolyzes. Therefore, it has a shorter duration of effec-tiveness than distilled mustard (HD).

New substances (hydrolysis products) form when anagent or comp ound reacts with w ater. In certain caseshydrolysis does not completely destroy the toxicity of anagent or compound. The resulting hydrolysis products may

also be toxic. Examples include lewisite and other agencontaining arsenic.

Stability in StorageStability in storage determines the practical usefulne

of an agent or chemical comp ound . If a candidate agendecomposes in storage, it will have little value regardlesof any other properties that may recommend it. The addtion of stabilizers to agents will slow decomposition anpolymerization.

Action on Metals, Plastics,Fabrics, and Paint

The action between an agent or compound and certaimaterials limits the use of that chemical or materiaChemicals that are acids or form acids have a corrosiveffect on metals, leather, fabrics, and paints, except chemcal agent-resistant coatings.

Physiological Aspects

Chemical agents have various p hysiological effects uponthe human body. Most agents are used for their toxic effectsto produce a harmful physiological and/ or psychologicalreaction when app lied to the body externally, whenbreathed, or w hen taken internally. Most agents cause adisorganization of bod y functions, as d escribed in Chap -ter 2 for individu al chemical agents and in Chap ter 3 forchemical compou nds.

Routes of Entry

Chemical agents may enter the body by several routes.Any part of the respiratory tract, from the nose to the lungs,ma y absorb inhaled ga ses, vap ors, and aerosols. Moisttissues, such as the lungs or eyes, absorb vapors mostrap idly. The skin, especially areas a ffected by sw eat, canalso absorb vap ors. The su rface of the skin, eyes, andmucous membranes can absorb droplets of liquids andsolid particles. Wounds or abrasions are p robably moresusceptible to absorption than the intact skin. Chemical

agents can contaminate food and drink, and therefore thbody can absorb th em throu gh the gastrointestinal tracThe onset and severity of signs may vary, depending upothe route as w ell as the amount of exposure.

Some agents are highly toxic if absorbed through the skior eyes; others are nontoxic by those routes. Nerve agenexert their full toxic effects through the skin, th e eyes, anthe lungs. The primary blood agent h azard results frominhalation, not skin or eye absorption because of agenvolatility. Liquid hyd rogen cyanide (AC) can be toxic b

absorption through the skin or the eyes. However, liquiAC rarely exists in a military situation. Skin and eye effectalthough severe, are usually local. Blister agents damagskin and any other tissues that they contact; if absorbed isufficient quan tity, these agents can cause systemic poisoning. The vomiting compoun ds an d choking agents exetheir effects only if inhaled. The tear compounds normallhave little effect on the body except temporary irritation tthe eyes and u pper r espiratory tract.


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DosageThe dose is the amount of compound the body takes in

or absorbs. It is usually expressed as milligrams perkilogram (mg/ kg) of body weight. Median lethal dosedescribes the degree of toxicity of a substance.

Median Lethal Dosage (LD 50) of Liquid AgentThe LD50 is the amou nt of liquid agent expected to kill50 percent of a group of exposed, unprotected personnel.

Median Incapacitating Dosage (ID50) of Liqu idAgent

The ID50 is the amount of liquid agent expected toincapacitate 50 percent of a group of exposed, unprotectedindividuals.

For airborne chemical agents, the concentration of agentin the air and the time of exposure are the important factorsthat govern the dose received. The dosage may be inhaled(respiratory) or absorbed throu gh th e eyes (ocular) or

through the skin (percutaneous). Dosages are based onshort exposu res ten minutes or less. Toxicity is generallyidentified by reference to the lethal dosage,

Med ian Lethal Dosage (LCt50) of a Vapor orAerosol

The median lethal dosage of a chemical agent employedfor inhalation as a vapor or aerosol is generally the LCt50.The LCt50 of a chemical agent is the dosage (vapor con-centration of the agent multiplied by the time of exposure)that is lethal to 50 percent of exposed, unprotected person-nel at some given breathing rate. It varies with the degreeof protection provided by masks and clothing worn by

personn el and by the breathing ra te. If individu als arebreathing faster, they will inhale more agent in the sametime, increasing the dose received.

Med ian Incapacitating Dosage (ICt50) of a Vapor orAerosol

For inhalation effect, the median incapacitating dosageis the ICt50. The ICt50 is the amount of inhaled vap or thatis sufficient to disable 50 percent of exposed, unprotectedpersonnel. The unit used to express ICt50 is mg-min/ m

3.

Note: You may also express dosages in amountsother than the median dosage. For example, theLCt 25 is the dosage of vapor that would kill 25 percentof a group of exposed, unprotected personnel; ICt 90is the vapor dosage that w ould incapacitate 90 per-cent of a group of exposed, unprotected personnel.

Modifying FactorsAfter exposure to a chemical agent vapor a person may

show signs and symptoms that are less or more severe thanexpected. Severity depends upon some of the followingvariables:

How long the person held his or her breath during shortexposure.Speed with w hich he or she donned the mask.Proper fit of the mask.Whether the body absorbed the agent through the skin.Whether the agent stimulated the rate of breathing.

Rate and depth of breathing of the person at the timeof exposure.Amount of physical exertion of the person at the timeof exposure.Rate of detoxification, especially if exposure was long.

For tabulation p urp oses we ignore su ch variables. TheCt values measure the amount of agent a person receiveswhen breathing at a normal rate in a temperate climate withaverage humidity. Dosages are given for 70-kilogram (kg)individuals with very light activity (for example, desk work)with a breathing rate of 15 liters per minute. These valuesprovide a basis to compare various agents.

The skin vapor dosage is equal to the time of exposure

in minutes of a persons unprotected skin mu ltiplied by theconcentration of the agen t cloud. The p article size, thetime, and the concentration affect the physiological effec-tiveness of skin and respiratory vapor dosages. Retentionby the lungs and absorption through the skin are functionsof physical characteristics, such as particle size.

Rate of DetoxificationThe hum an bod y can detoxify some toxic materials. This

rate of detoxification is the rate at w hich the bod y cancounteract the effects of a poisonous substance. It is animportant factor in d etermining the hazards of repeatedexposure to toxic chemical agents.

Most chemical agents are essentially cumulative in theireffects. The reason is that the human body detoxifies themvery slowly or not at all. For example, a one-hour exposu reto HD or CG followed within a few hours by an otherone-hour exposure has about the same effect as a singletwo-hour exposure. Continued exposure to low concentra-tions of HD may cause sensitivity to very low concentra-tions of HD. Other chemical agents also have cumulativeeffects. For exam ple, an initial exposu re to a small (lessthan lethal) amou nt of Sarin (GB) would decreasecholinesterase levels; a second quantity less than the LD 50could be enough to kill. (Although the body can d etoxify itto some extent, GB is essentially cumulative.)

Some compounds have a detoxification rate that is sig-nificant. Because the body detoxifies such chemical agentsas AC and cyanogen chloride (CK) at a fairly rapid rate, ittakes high concentrations of these agents to produce max-imum casualty effects.

Rate of ActionThe rate of action of a chemical agent is the rate at which

the bod y reacts to or is affected by th at agent. The rate

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varies wid ely, even to those of similar tactical or ph ysiologi-cal classification. For example, blister agent HD causes noimmed iate sensation on the skin. Skin effects usually occurseveral hours later (some cases result in delays of 10 to 12days before symptoms app ear). In contrast, lewisiteproduces an immediate burning sensation on the skin uponcontact and blistering in about 13 hours. Decontamination

immediately (within four to five minutes) will preventserious blister agent effects.

With the single exception of arsine (SA), the nerveagents and the blood agents are very fast acting. Vomitingcompoun ds also exert their effects within a short time afteinhalation. In general, agents that are inhaled or ingestedwill affect the body m ore rapid ly than those that contacthe skin. To avert death, first-aid measures, such as administering antidotes, generally must follow within a few

minutes after the absorption of a lethal dosage of anyagents.

Agent MixturesMixing chemical agents with each other or with other

materials can alter the characteristics and effectiveness ofagents. This alteration occurs through changes in physicalproperties, physiological effects, or toxicity.

Mixtures may lower the freezing point, increasing agenteffectiveness over a wider temperature range. Distilledmustard has a freezing point of 14.5C (55F); but a mixture(37:63) of it and lewisite will freeze at -25C.

The add ition of thickeners or thinners to agents w illincrease or decrease persistency. Soman mixed with thick-eners will increase persistency. Riot control agents mixedwith thinners will decrease persistency.

In addition to changing the physical properties, mixingagents together will create special problems through theiphysiological effects. These problems can pr odu ce difficulty in identification, immediate and delayed effects, or contact and v apor h azards occurring simu ltaneously. Sommixtures would make it difficult to maintain the seal of thmask.

Mixing some agents can increase the toxic effects, eithe

by a synergistic effect or by an improved absorptionthrough the skin. For example, dimethylsulfoxide (DMSOcan penetrate the skin and carry substances mixed with iinto the body at a very rapid rate.

Section III. Militarily Significant Aspects of Biological Agents

Classification of Biological Agents

Biological agen ts can be classified accord ing to th eirbiological type, u ses, operational effects, and physiologicalaction. The terms p ersistent and nonp ersistent describe

the continuing hazard posed by the agent remaining in theenvironment. Do not use these terms to classify biologicalagents.

Types of Biological AgentsBiological agents can be classified as pathogens, toxins,

or oth er agen ts of biological origin, such asbioregulators/ mod ulators (BRMs).

PathogensPathogens are disease-producing microorganisms, such

as bacteria, mycoplasm a, rickettsia, fun gi, or viru ses.Pathogens are either naturally occurring or altered by

rand om m utation or recombinant deoxyribonucleic acid(DNA) techniques. TM 3-216, FM 8-9, and FM 8-33 detailthe characteristics of naturally occurring pathogens.

ToxinsToxins are p oisons naturally produ ced through th e me-

tabolic activities of living organisms. They are organicchemical compounds, such as proteins, polypeptides, and

alkaloids, that come from a variety of biological sourcesThese sources include microorganisms and various plantand animals. Although toxins were initially isolated from

living organic sources, manufacture of some by chemicasynthesis or other biochemical processes is feasible. Industrial fermentation processes can obtain large amountof highly concentrated bacterial toxins. Laboratories cansynthesize toxins composed of only 10 to 12 amino acids.

Bioregulators/ModulatorsBioregulators/ mod ulators (BRMs) are biochem ica

compoun ds, such as p eptides, that occur naturally in organisms. These peptides and other small molecules can acas neurotransmitters and/ or can modify neural responsesIt is feasible to produce some of these compounds bychemical synthesis. It is probable that neuropeptides wil

become available soon as a result of research in the medicacommunity. Although BRMs have potential as biologicaagents, this manual does not include them.

UsesBiological agents can be d irected against p ersonnel

plants, animals, or materiel. Food and industrial productcan be rendered unsafe or unfit for use by contamination


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or by the effects resulting from contamination with biologi-cal agents.

AntipersonnelBiological antipersonnel agents are those that are effec-

tive directly against humans. The Threat would select theseagents on the basis of the agents ability to cause death or

disability. The Threat might use these agents againstselected persons or grou ps or to prod uce mass casualtiesover large areas. This use could resu lt in p hysical andpsy chological effects that could w eaken or d estroy theability to resist aggression. Potential biological antiperson-nel agents include toxins, bacteria, rickettsiae, viruses, andfungi.

AntianimalBiological antian imal agents ar e those that cou ld be

employed against an imals to incapacitate or d estroy themthrough disease. The main p urp ose of the use of theseagents is to affect humans indirectly by limiting their food

supply. TM 3-216 contains information on potential an-tianimal agents.

AntiplantBiological antiplant agents are live organisms that cause

disease or dam age to plants. An enem y may u se theseagents to attack food or economically valuable (cash ormoney) crops. The enemy could thereby reduce a nationsability to resist ag gression. TM 3-216 describes some an-tiplant agents.

AntimaterielAntimateriel agents are organisms that d egrade or break

dow n some item of materiel. Most of the materiel damagedone by microorganisms is a result of natural contamina-tion that grows on ly und er very special conditions oftemperature and relative humidity. Fungi are responsiblefor damage to fabrics, rubber products, leather goods, andfoodstuffs. Some bacteria can use petroleum products asan energy source, causing residues that might clog fuel oroil lines. Other bacteria produce highly acidic compoundsthat cause pitting in metals. The use of antimateriel biologi-cal agents for military purposes appears unlikely. However,with ad vancing technology these agents could createpotential problems with stockpiled materiel.

Operational EffectsThe effects produced by biological agents can influencethe continued op erational effectiveness of un its in the field.Biological agents can p rod uce incapacitation, serious in-jury, or death. Biological agents are categorized arbitrarilyas lethal or incapacitating. Some microorganisms or toxinswill cause diseases that are usually lethal unless the target

popu lation is immu ne. Others will cause illnesses that areessentially incapacitating.

Lethal AgentsLethal biological agents are those that cou ld cause sig-

nificant mortality. Lethal agents can cause death in suscep-tible people, but from a practical standpoint death occurs

only in a certain percentage of those exposed. The mor-tality rates vary according to several factors. These factorsinclude the characteristics of the agent, the route of entry,the dose received, and, in the case of pathogens, the abilityof the host to resist infection.

Incapacitating AgentsIncapacitating agents usually do not kill healthy adults.

However, these agents can cause death in certain groups,such as the very young, the aged, or the infirm. Incapacitat-ing agents can cause infection or disease with militarilysignificant disability among susceptible, exposed people.

Transmissible AgentsPathogen s can be fur ther classified as tran smissible ornontransmissible agents. Some pathogens cause diseasethat is transm issible from p erson to p erson, which can leadto an epidemic. However, other microorganisms are non-transm issible. Toxins are not living organisms; their effectscannot spread from person to person.

Physiological ActionThe clinical effects of toxins may closely resemble those

of chemical warfare agents, such as nerve, blister, vomiting,or choking agents. Most toxins of m ilitary significancecause casualties primarily in one of two ways. These toxins

can be classified as either neurotoxins or cytotoxins by theway they act.

NeurotoxinsNeurotoxins interfere with nerve impulse transmission

and could be called nerve toxins. The neurotoxins exerthighly sp ecific effects up on the n ervou s system. Som eneurotoxins cause symptoms similar to those of chemicalnerve agents leading to convulsions and rigid paralysis.However, the mechanism causing the symptoms does notusually inhibit acetylcholine esterase. Many neurotoxinsblock the tran smission of impu lses along nerve and musclefibers. These neurotoxins can cause numbness or extreme

weakness, tremors, and m uscular incoordination leading tosevere mu scle weak ness and flaccid (limp or rag-doll)paralysis. Confusion, headache, blurred vision, and lightsensitivity (because of dilation of pupils) may occur. Someneurotoxins affect the central nervous system. Neurotoxinstend to act rapid ly.

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Cytotoxins Symptom s of exposure may resemble those of disease or oCytotoxins cause cellular destruction or interfere with various chemical agents. Cytotoxin effects may include

metabolic processes, such as cell respiration or protein irritation, blistering, and lesions of the skin; nausea osynthesis. Cytotoxins exert effects up on a va riety of tissues vomiting; hemorrhaging, bloody diarrhea and vomit; difor systems. These tissues or systems include the digestive, ficulty in breathing or sudden death.respiratory, and circulatory systems and the skin.

Duration of Effectiveness of Biological Agents

The du ration of effectiveness of a biological agent refersto the persistency of the agent in the environment. It variesgreatly betw een agents. It dep ends on th e characteristicsof the agent, the influence of environm ental factors, andany residual hazard generated through resuspension ofsettled biological particles by vehicle and troop movementsor wind.

Physical, Chemical, and BiologicalProperties

The duration of effectiveness of a biological agent doesnot generally relate to its physical properties; vapor pres-sur e or volatility are not significant factors for biologicalagents. Some toxins (for example, Staphylococcusenterotoxin, Type B) are stable in the environment and aremore resistant to heat, hydrolysis, or vaporization than G-or V-series nerve agents. The chemical structure of toxinscan strongly influence the stability of the agent to environ-men tal factors. High-molecular-weight toxins, such asproteins, are usually more sensitive to ultraviolet (UV)light, heat, and oxidation than low-molecular-weight, non-protein toxins. Many toxins are water-soluble.

Because pathogens are live exhibiting feeding, ex-

cretory, respiratory, reproductive, and defensive func-tionsany factors that reduce the viability will reduce theduration of effectiveness. Environmental conditions affectmost pathogens significantly unless altered or protected.

Weather and Terrain InfluencesSolar (ultraviolet) radiation, relative humidity, wind

speed, and temp erature gradient are the most imp ortant

weather factors in determining duration of effectivenessUltraviolet light affects most biological pathogens andsome toxins (especially high-molecular-weight proteins)However, encapsulation (natural, such as bacterial sporesor man-made protective coverings), addition of dyes to thspray fluid, or possibly genetic engineering (of pathogensmay p rotect some agents from sunlight and other destructive natural forces. Impurities in crude toxin cultures canstabilize the toxins and / or enhance toxicity.

FM 3-3 and FM 3-6 discuss the field behavior of biological agents. These manuals also discuss the impact oweather effects and terrain features (soil, vegetationrelief) on du ration. FM 8-9 discusses in detail the atmospheric influence on biological aerosols of pathogens.

Methods of DisseminationBiological agents may be disseminated as aerosols, liq

uid drop lets (toxins only), or dry pow ders. To a certainextent the state in wh ich an agent norm ally exists determines its use, duration of effectiveness, and physiologicaaction. It also determines the type of system used for itdissemination. Live microorganisms usually grow in moist environment. Therefore, these agents may be dis

seminated in a liquid medium as wet aerosols. Howeverthe technology exists to store microbiological materials aa powder (usually by a freeze-dried process), suitable fodissemination. Dissemination of spores and certain toxinas dry powders is likely. Many toxins are water-soluble, anddissemination could be as sprays or wet aerosols. Ingeneral, agents disseminated as a dry p owder will survivlonger than those disseminated as wet aerosols.

Characteristics of Likely Potential Biological Warfare Agents

Major militarily sign ificant characteristics for all biologi- ease-causing agents against US forces. Several factorcal warfare (BW) agents include would limit the selection. These limiting factors include

A susceptible population. biological properties, environmental factors, and methodHighly infectious or toxic properties. of dissemination. FM 8-9 addresses biological operationAvailability or adaptability to a large-scale production. and selection of live biological agents based on their charStability in storage, in handling, and after dissemina- acteristics.tion.Suitability for aerosol dispersion. Route of Entry

Advances in technology have increased the capability for The type of symptoms p rodu ced by biological agentproduction and modification of biological materials. The depends not only on the agent characteristics but also uponThreat could u se a considerable num ber of toxic or dis- the route of entry. The places where pathogens gain entr

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into the body are the p ortals of entry. The three importantportals of entry are the skin, the respiratory tract, and thedigestive tract. The respiratory system is much more sus-ceptible to penetration than are the other portals of entry.The lungs have a large surface area, very thin air sacs, anda large blood supply. The body is more resistant to invasionby microorganisms through the digestive tract and the skin.

However, penetration across the skin and mucousmembranes may occur. This is particularly true of abraded(broken) surfaces. Toxins (for example, mycotoxins) mayalso have a direct action on the skin or mucous membranes.

Biological agents may be encountered by natural routes,such as in w ater and food or by vectors. However, therespiratory route app ears most likely to cause m ass casual-ties. As a result of inha lation, many p athogens will initiallyprod uce flu-like symp toms or other effects on therespiratory system. Within one to five days most pathogenswill produce a unique pattern of illness. The pattern maybe fever, sore throat, stiff neck, rash, necrologic or mentalabnormalities, pneum onia, diarrhea, dysentery, hemor-

rhaging, or jaundice. Toxins absorbed through therespiratory tract might produce signs and symptoms verydifferent from those acquired through natural occurrence.

For certain organisms causing gastrointestinal diseases,the d igestive tract is the expected rout e of entry. Typicalsymptom s includ e nausea, vomiting, diarrhea, ordysentery. The gastrointestinal tract is often the naturalrou te of infection or intoxication for toxins (for example,Botulinum toxin and Staphylococcal enterotoxins). Thesigns and symp toms wou ld be similar to the natu ral infec-tion, however, the onset may be much m ore rapid.

Dosage

Most BW agents are, by weight, thousands of times morelethal or effective than equivalent amounts of chemicalwarfare agents found in modern chemical arsenals. TheseBW agents also have greater downwind hazard distancesassociated with air-contaminating clouds than do chemicalagents.

Infective DoseThe infective dose is the number of microorganisms or

spores required to produce an infection. It is comparableto the effective dose for chemical agents.

Lethal DoseSome pathogens produce toxins that can result in disease

(for example, Botulinum, cholera, diphtheria, typhus). Themedian lethal dose (LD50) expresses the toxicity ofblotoxins. It is obtained from experim ental animal inves-tigation. The extreme toxicity of many toxins causes thelethal dose to be much smaller than that of chemical agents.Hence, units of micrograms (g) or even nanograms (ng)may be used instead of milligrams (mg) in expressingtoxicity.

Most toxicity data are based on injection (into the bloodor into the body cavity) into animals. Estimates for humantoxicity are made from animal data. Some human toxicitydata are based on accidental contact, ingestion, or inhala-tion of these natural poisons.

Rate of ActionThe rate of reaction to toxins varies widely. Rapid-acting

toxins generally incapacitate within minutes. Delayed-ac-ting agents may take several hours to days to incapacitate.The times given for the onset of symptoms and the descrip-tions apply to dosages at or about LD 50 unless noted.Dosages much larger than LD50 may occur du ring toxinemployment in a BW attack, especially with in zone I of thepoten tial biological haz ard ar ea. Personn el exposed tothese dosages may experience a faster onset and moresevere symptoms. Add itional symptoms may also occur.

The time to maximum effects for pathogens is normally

more than 24 hours (unless the path ogen prod uces a toxin).However, the incubation periods of microorganisms usedin BW may be far shorter than those expected by examiningthe natural disease. Initial dose inhaled may be many timesthe infective dose. In addition, selective breeding or geneticengineering may have altered the incubation p eriod.

Comparison of Pathogens and Toxins

Biological agents, whether biological toxins or exposur e. Dosages given for toxicity ar e for 70-kilogrampath ogens, can be lethal or incapacitating. How ever, be- individuals w ith very light activity (for example, desk work)cause pathogens are live agents but toxins are nonliving and a breath ing rate of 15 liters per minu te. Increased

biochemical compounds, there are major differences. breathing rate (for example from increased activity) willThese differences are in their t oxicity, stability, lethality, decrease the respiratory d osages proportionally because aand time to effects, as well as per sistence in th e field. greater volume of agent is inhaled in th e same time.FM 3-3 addresses field characteristics of biological agents. Dosages given are for less than two-minute exposure.Table 1-1 summarizes important pathogen and toxin field The same total dosages received through longer exposureproperties. times at lower concentrations w ill redu ce the symptom s

The response to the toxic agent is a function of the total somewhat.dose received, the length of exposure, and the route of

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Chapter 2

C h e m i c a l A g e n t s a n d T h e i r P r o p e r t i e s

Chemical agents can be separated into group s accord ing to the p otential severity

of their effects: lethal, blister, and incapacitating agents. This chapter contains the

physical, chemical, and physiological properties of specific chemical agents that

migh t be used or encoun tered in the field. It also gives brief information on their

use, detection, identification d econtam ination, and the p rotective measures to be

taken against them . As noted , Append ix B gives a comp arison of the prop erties of

chemical agents. Temp eratur es are listed in d egrees Celsius (C); other d ata are in

various m etric un its. App end ix C presents a table of English-metric equivalents.

App endix D p resents temp erature conversions.

Section I. Lethal Chemical AgentsLethal chemical agents are those agents that primarily

cause deaths among target personnel. They includ e thechoking, nerve, and blood agents.

Choking AgentsChoking agents injure an unp rotected person chiefly in

the respiratory tract (the nose, the throat, and particularlythe lungs). In extreme cases membranes swell, lungs be-come filled w ith liqu id, and d eath resu lts from lack ofoxygen; thus, these agents choke an u nprotected person.Fatalities of this type are called dryland drownings.

Phosgene (CG)CG, normally a chemical agent with a short agent-cloud

duration, was used extensively in World War I. In fact,more than 80 percent of World War I chemical agentfatalities resulted from CG.

CG is a colorless gas with a n od or similar to that ofnew-mown hay, grass, or green corn, which may go u n-noticed until at toxic levels. It tends to hug the ground;vapors may linger for some time in trenches and low placesun der calm or light wind s. CG readily condenses to a

colorless liquid below 46F (7.8C). It reacts rap idly withwa ter, so rain, fog, and den se vegetation redu ce the con-centration in the air.

CG is used as a delayed-casualty agent that causes fluidbuildup in the lungs that can cause dryland drowning.During and immediately after exposure, coughing andwheezing are likely however, exposure to low concentra-tions causes n o ill effects for three h our s or m ore. Theseverity of poisoning cannot be estimated from the imm e-diate symptoms. The full effect is not usually apparent untilthree or four hours after exposure. Severe cases can resultin dryland d rowning, usually within 24 hours. With propercare a victim can recover if the amou nt of CG received isless than lethal. The protective mask provides protection.If a person inh ales some agent, he should continue normalcombat du ties unless he has respiratory distress.

Selected data regar ding th e chem ical proper ties andtoxicity of this agent follow (Table 2-l). These includeChemical Abstracts Service (CAS) registry number andRegistry of Toxic Effects of Chemical Substances

(RTECS) reference number.

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Diphosgene (DP)DP (Table 2-2) is a colorless liquid with an odor similar

to that of new-mow n hay, grain, or green corn. DP has amuch higher boiliig point than CG. Because DP has astronger tear ing effect, it has less surprise value th an CGwh en used on troop s. Furtherm ore, its low er volatility(vapor pressure) adds to the difficulty of setting up an

effective surprise concentration.

DP can prod uce delayed or immediate casualties,depend ing up on the d osage received. Because the bodyconverts DP to CG, the physical effects are the same forboth agents. Immed iate symptoms may follow exposure toa high concentration of DP; a delay of three hours or moremay elapse before exposure to a low concentration causesany ill effects. The protective mask provides protection

from DP.

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Nerve Agents.

Nerve agents are organophosphate ester derivatives ofphosp horic acid. They are generally d ivided into the G-agents, which in the unmodified state are volatile, and theV-agents, which tend to be more persistent. Even G-agentsare capable of being thickened with various substances toincrease the persistence and penetration of the intact skin.The principal nerve agents are Tabun (GA), Sarin (GB),Soman (GD), and VX. (In some countries the V-agents areknown as A-agents.)

The G-agents are fluorine- or cyanide-containing or-

ganoph osphates. In pu re form they are colorless liquids.Their solubility in water ranges from complete miscibilityfor GB to alm ost total insolubility for GD. They hav e aweakly fruity odor but in field concentrations are odorless.Clothing gives off G-agents for abou t 30 minutes aftercontact with vapor; consider this fact before unmasking.

The V-agents are sulfur-containing organophosphorouscompounds. They are oily liquids with high boiling points,low volatility, and resultant high persistency. They areprimarily contact hazard s. They are exceptionally toxic; thelimited amount of vapor they produce is sufficient to be aninhalation hazard. They have very limited volubility inwater and are hydrolyzed only minimally. V-agents affectthe body in essentially the same manner as G-agents.

The nerve agen ts are all viscous liquids, not nerve gasper se. However, the vapor pressures of the G-series nerveagents ar e sufficiently high for the vap ors to be lethalrap idly. The volatility is a ph ysical factor of most imp or-tance. GB is so volatile that small droplets sprayed from aplane or released from a shell exploding in the a ir maynever reach the ground. This total volatilization means thatGB is largely a vap or hazard . At the other extreme agentVX is of such low volatility that it is mainly a liquid contacthazard. Toxicity can occur from the spray falling on onesskin or clothes and from touching surfaces on w hich the

spray has fallen. GD is also mainly a vapor hazard, whileGA can be expected to contaminate surfaces for a suffi-ciently long time to provide a relevant contact hazard.

Thickeners added to GD increase persistence in thefield. The thickened agents form large drop lets that p ro-vide a greater concentration reaching the ground and agreater contact hazard than the unthickened forms.

The relative volubility of these compounds in water andsoil is of significance because it r elates to their disposition.

The ability of GB and GA to mix with water means thwater could wash them off surfaces, that these agents ceasily contaminate w ater sources, and that they w ill npenetrate skin as readily as the more fat-soluble agents Vand GD. G-agents spread rapidly on surfaces, such as skiVX spreads less rapidly, and the thickened agents veslowly. The moist surfaces in the lungs absorb all the agenvery w ell.

Both the G- and V-agents have the same ph ysiologiaction on humans. They are potent inhibitors of the enzym

acetylcholinesterase (AChE), wh ich is required for tfunction of many nerves and muscles in nearly every muticellular animal. Normally, AChE prevents the accumution of acetylcholine after its release in the n ervous systemAcetylcholine plays a vital role in stimulating voluntamuscles and nerve endings of the autonomic nervous sytem and many structures within the central nervous systeThus, nerve agents that are cholinesterase inhibitors pemit acetylcholine to accumulate at those sites, mimickithe effects of a massive release of acetylcholine. The majeffects will be on skeletal muscles, parasympathetic enorgans, and the central nervous system.

Individuals poisoned by nerve agents may display tfollowing symp toms:

Difficulty in breathing.Drooling and excessive sweating.Nausea.Vomiting, cramps, and loss of bladder/ bowel controTwitching, jerking, and staggering.Headache, confusion, drowsiness, coma, and convusion.

The number and severity of symptoms depend on tquantity and route of entry of the nerve agent into the bodWhen the agent is inhaled, a prominent symp tom is pipointing of the pu pils of the eyes and dimn ess of visi

because of the reduced amount of light entering. Howeveif exposure has been through the skin or by ingestion ofnerve agent, the pupils may be normal or only slightly moderately reduced in size. In this event, diagnosis murely upon the sym ptoms of nerve agent poisoning oththan its effects on the pupils.

Exposure through the eyes produces a very rapid onsof symptoms (usually less than 2 to 3 minutes). Respiratoexposure u sually results in onset of symp toms in 2 to


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minutes; lethal doses kill in less than 15 minutes. Liquid inthe eye kills nearly as rapidly as respiratory exposure.

Symptom s appear m uch more slowly from skin absorp-tion. Skin absorption great enough to cause death mayoccur in one to two hours. Respiratory lethal dosages killin one to ten minutes, and liquid in the eye kills nearly asrapidly. Very small skin dosages sometimes cause localsweating and tremors but little other effects. Nerve agentsare cumulative poisons. Repeated exposure to low con-centrations, if not too far apart, will produce symptoms.

Treatment of nerve agent poisoning includes use of thenerve agent antidote (atropine and 2-PAM chloride).Atrop ine blocks acetylcholine; 2-PAM Cl, reactivates theenzyme AChE. As time passes w ithout treatment the bind-ing of nerve agents to AChE ages and the 2-PAM Cl canno longer remov e the agent. Certain agents, such as GD,

that age rapidly m ay resist treatment if it is not promp t.Therefore, an antidote enhancer, pyridostigmine bromide(PB), is available to US forces in active theaters of opera-tion. PB pretr eatment increases the victims surv ivabilitywhen the antidote is used after exposure to nerve agents.

Tabun (GA)GA is a brow nish to colorless liquid th at gives off a

colorless vapor. GA (Table 2-3) was the first of the nerveagents developed by the Germans before World War II. Itis about 30 times as toxic as phosgene, which was used inWWI. It enters the body primarily through the respiratorytract, but it is also highly toxic through the skin and diges-tive tract. It is approximately 20 times more p ersistent thanGB but not as stable in storage.

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Sarin (GB) The physiological symptoms of GB are essentially the samThe Germans d eveloped GB after they developed GA, as those of other nerve agents.

hence the designation GB (Table 2-4). It is a volatile liquidat room temperatu re. Pure GB is od orless and colorless.


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Soman (GD) a few minu tes antidotes are not as effective for GD poisoGD is a colorless liquid that gives off a colorless vapor. ing as they are for other nerve agents. The addition of age

Soman is the most poisonous of the G-agents, apparently thickeners increases GD persistency and hazard. The usubecause of the ease w ith which it can penetrate into the thickened form of GD is designated TGD. VR-55

central nervous system. The physiological effect of GD is probably an other d esignation for thickened Soman. Sessentially the same as that of GA and GB. However, after Table 2-5.


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GF through the skin and digestive tract. It is a strongThe agent GF is a fluoride-containing organoph osphate. cholinesterase inhibitor. Toxicity information reports

It is a potential nerv e agent. It is a slightly volatile liquid LD5O values in mice from 16 g/ kg to 400 g/ kg, comparedthat is almost insoluble in water. It enters the body primari- to LD50 of 200 g/ kg for Sarin. It is approximately 20 timesly throug h the resp iratory tract but is also highly toxic more persistent that Sarin. See Table 2-6.

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VX volatility, liquid droplets on the skin do not evaporaThe US stan dard V-agent is VX (Table 2-7). It is a very quickly, thereby increasing absorption. VX by this pe

persistent, odorless, amber-colored liquid, similar in ap- cutaneous route is estimated to be more than 100 times pearance to m otor oil. Althoug h VX is many times more toxic as GB. VX by inh alation is estimated to be tw ice persistent than the G-agents, it is very similar to GB in toxic as GB.

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VxAnother V-agent of interest is Vx, called V sub x (Table

2-8). Another designation for Vx is V-gas. The propertiesof Vx are similar to those of VX. It is nearly ten times morevolatile than VX but is very persistent in comparison to theG-agents. The m olecular w eight of Vx is 211.2. Listedvalues are calculated, Information on this agent is limited.The physiological action, protection, and decontaminantsfor Vx are th e same a s for VX.

Binary Nerve Agents (GB2 and VX2)GB2 and VX2 are th e d esignations for Sarin (GB) and

agent VX which are formed in binary r eactions. GB2 and

VX2 have been d eveloped to decrease hazard s of manu facturing storing, and handling unitary nerve agents. In binaryweap ons tw o relatively non toxic chemicals are m ixed inflight to form the agent.

GB2 is formed by the reaction of methylphosp honidfluoride (DF) (see DF) with a mixture of isopropyl al

cohol and isopropylamine (OPA) (see OPA).VX2, binaryVX, is formed by there action of O,O-ethy(2-diisopropylaminoethyl) methylphosphonite (see QLwith sulfur (see NE and NM).

Compounds used to produce the binary nerve agents arnot chemical agents themselves; Chapter 3 discusses thescompounds.

Most blood agents are cyanide-containing compounds,absorbed into the body primarily by breathing. AC and CKare the imp ortant agents in this group . Blood agents arehighly volatile and, therefore, nonpersistent even at verylow temperatures. These agents can be dispersed by artil-lery shell, mortar, rocket, aircraft spray, or bomb. AC hasan odor like bitter almonds; CK is somewhat more pungent.The odor of CK often goes u nnoticed because CK is soirritating to the eyes, nose, and r espiratory tract. At high

Blood Agents

concentrations both compounds cause effects withinseconds and death within minutes in unprotected personnel. The cyanides affect body fu nctions by poisonin g thcytochrome oxidase system, this poisoning prevents celrespiration and the normal transfer of oxygen from thblood to body tissues. Cyanogen chloride also acts as choking agent. The standard protective mask gives adequate protection against field concentrations.

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Hyd rogen Cyanide (AC)Although the US armed forces do not stockpile AC

(Table 2-9), it is of interest because of its availability. It canbe readily synthesized in large quantities and is commer-cially available. Potential enemies m ay hold large stock-piles. Some states use hydrogen cyanide for capital

punishment. Pure AC is a nonpersistent, colorless liquidthat is highly volatile. It is used as a quick-acting casualtyagent that causes death within 15 minutes after a lethal dosehas been received.

AC has a faint odor, similar to bitter almonds, thatsometimes cannot be detected even in lethal concentra-tions. AC strongly stimulates breathing; the mask must be

put on as fast as possible. The pink color of the casualtyslips, fingernails, and skin suggests hydrogen cyanidepoisoning. Exposure to high concentrations m ay causeinstant loss of consciousness and d eath. A nonlethal dosagewill cause moderate symptoms, but the patient can recover.Low doses have alm ost no effect on the bod y. AC is less

persistent than other blood agents. The protective maskprovides protection against field concentrations of AC.Liquid AC can penetrate skin. However, because of its highvolatility, liquid AC is not likely to be encountered in thefield, and protective clothing is required only in very un-usual situations.

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Cyanogen Ch loride (CK)CK (Table 2-10) is a colorless, highly volatile liquid with

a pungent, biting odor that will go unnoticed because of theagents tearing and irritating p roperties. Althou gh CKquickly evaporates, vapors may persist in the forest orjungle for some time u nder suitable weather conditions.Normally, CK is nonpersistent and is used as a quick-actingcasualty agent.

CK irritates the respiratory tract similar to p hosgene;fluid may accumulate in the lungs much faster than in

phosgene poisoning. Skin and eye toxicity are too low to bof military importance, but CK is highly irritating to eyeand mucous membranes. The general action of CK, interference with use of oxygen by the body tissues, is similar tthat of AC. However, CK differs from AC in that it hastrong irritating and choking effects and slows breathingThe protective mask protects against CK; a high concentration, however, may degrade the falter and reduce the maskprotective capability.

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Arsine (SA) creased exposu re causes chills, nau sea, and v omiting.SA is a gas with a mild, garliclike odor. It is used as a Severe exposure damages blood, causing anemia. It is a

delayed-action casualty agent th at interferes with th e carcinogen. The protective mask provides adequatefunctioning of the blood and damages the liver and kidneys. protection. See Table 2-11.Slight exposure causes headache and uneasiness. In-

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Section II. Blister Agents (Vesicants)All of the blister agents are p ersistent, and all may be

employed in the form of colorless gases and liquids. Blisteragents dam age any tissue that they contact. They affect theeyes and lungs and blister the skin. They damage therespiratory tract when inhaled and cause vomiting anddiarrhea when absorbed. Vesicants poison food and waterand make other supplies dangerous to handle. They mayprod uce lethalities, but skin damage is their main casualty-producing effect. The severity of a blister agent burn direct-ly relates to the concentration of the agent and the du rationof contact with the skin. In addition to casualty production,blister agents may also be used to restrict use of terrain, toslow movements, and to hamper use of materiel and instal-lations.

During World War I mu stard (H) was the only blisteragent in major use. It had a recognizable, distinctive odorand a fairly long d uration of effectiveness und er norm alweather conditions. Since then, odorless blister agents have

been developed that vary induration of effectiveness. Mostblister agents are insidious in action; there is little or nopain at the time of exposure. Exceptions are lewisite and

phosgene oxime (CX), which cause immediate pain oncontact. CX prod uces a wheal (similar to a bee sting) ratherthan a water blister, which the other blister agents produce.

Note: Fluid in mustard agent blisters may be quite irritat-ing fluid in lewisite blisters is nontoxic and nonvesicant.

Blister agents can be described as mustards, arsenicals,or urticants. The mustards (H, HD, HN-1, HN-2, andHN-3) contain either sulfur or nitrogen. The next para-graphs d iscuss the m ustard s. The arsenical (ethyl-dichloroarsine [ED], methyldichloroarsine [MD], andphenyld ichloroarsine [PD]) are a group of related com-pou nd s in wh ich arsenic is the central atom. Arsenicalhydr olyze rapidly and are less toxic than other agents ofmilitary interest. The discussion of arsenical chemicalagents appears later in this chapter. Also later in thischapter is a discussion of urticants and, specifically, theprincipal urticant of m ilitary interest, CX. Mustard s andarsenical are sometimes mixed to alter their properties for

military effectiveness; they may also be employed withthickeners.

MustardsThis group of agents includes the sulfur mustards (H and

HD) which are chlorinated thioethers, and the nitrogenmustards (HN-1, HN-2, and HN-3) which are consideredderivatives of ammonia. The nitrogen mustards havenitrogen as the central atom with the h ydrogen atomsreplaced by various organic groups. Derivatives of thenitrogen m ustards have been u sed in the treatment of

certain types of cancer. HD and HN-3 are the principalmilitary representatives of sulfur and nitrogen mustards.The mustards can penetrate skin and a great number of

materials. These materials include wood, leather, rubber,and paints. Because of their physical properties, mustardsare very persistent under cold and temperate conditions. Itis possible to increase their persistency even more by dis-solving them in thickeners. Mustards are less persistent inhot climates but can reach relatively high concentrations inair because of greater evaporation rate.

Levinstein Mustard (H)Levinstein mustard is the original mustard (gas) of

World War I vintage. It contains about 30-percent sulfurimpu rities, which give it a pronoun ced odor. These im-purities lessen the effectiveness of H but depress its freez-ing point tw o to five degrees. Other prop erties of H areessentially the same as those for distilled mustard, which isdiscussed next.

Distilled Mustard (HD)HD originally was prod uced from H by a pu rification

process of washing and vacuum distillation. HD (Table2-12) is a colorless to amber-colored liquid with a garliclikeodor. HD has less odor and a slightly greater blisteringpower than H and is more stable in storage. It is used as adelayed-action casualty agent, the duration of which

depends upon the munitions used and the weather. Al-though HD is heavier than water, small droplets will floaton water surfaces and present a hazard.

The effects of HD are usu ally delayed for 4 to 6 hours,but latent periods have been observed for up to 24 hours.The higher the concentration, the shorter the interval oftime from exposure to the first symptoms. Mustard actsfirst as a cell irritant and finally as a cell poison on all tissuesurfaces contacted. Early symptoms include inflammationof the eyes; inflam mation of the nose, throat, trachea,bronchi, and lung tissue; and red ness of the skin; blisteringor ulceration may follow. Effects may include a more at-ease attitud e, vomiting, and fever, beginning about the

same time as skin reddening. The eyes are very sensitive tolow concentrations; skin damage requires higher con-centrations. Wet skin absorbs more mustard than does dryskin. For this reason H D exerts a casualty effect at lowerconcentrations in hot, humid weather, because the body ismoist with perspiration. The protective mask and clothing

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provide adequate protection, but protection against large more susceptible to local and overwhelming infections thandroplets, splashes, and smears requires impermeablecloth- the normal individual. Injuries produced by HD heal muching. HD has a very low detoxification rate; therefore, very more slowly and are more susceptible to infection thansmall repeated exposures are cumu lative in the body. burns of similar intensity produced by physical means or by

Individuals also can become sensitized to mustard. most other chemicals.Amou nts app roaching the lethal dose make casualties

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Nitrogen Mustard (HN-1) a delay of 12 hou rs or more before skin-damagingHN-1 (Table 2-13) is similar to m ustard in its properties symptoms are felt.

and effects; however, it is more volatile and less persistent Nitrogen mu stards act more quickly on the eyes thanthan m ustard bu t only one-fifth as dam aging and n ot as does HD. The eyes are very susceptible to low concentra-stable. HN-1 is a colorless liquid with a faint, fishy or musty tions of nitrogen m ustard , while a high concentration isodor. It is used as a delayed-action casualty agent that has required to significantly da mage th e skin or resp iratory

tract insofar as single exposures are concerned. Mild vapor

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exposure may prod uce no skin lesions. Severe vapor ex-posur e or exposure to liquid HN will result in redness ofthe skin, causing irritation and itching. Later blisters mayappear in the red area. The skin lesions are similar to thosecaused by H D. The body d oes not detoxify HN -l; there-fore, it is cumulative.

Effects on the resp iratory tract are the sam e as those ofmu stard: irritation of the n ose and throat, hoarsenessprogressing to loss of voice, and a persistent cough. These

effects can progress to fever and labored breathing.Bronchial pneumonia may appear after 24 hours.

Following ingestion or systemic absorption, the nitrogenmustards injure the intestinal tract. Severe diarrhea, w hichmay be bloody, occurs. Ingestion of 2 to 6 milligrams causesnausea and vomiting.

The protective mask and protective clothing provideadequate protection, but protection against large droplets,splashes, and smears requires impermeable clothing.

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Nitrogen Mustard (HN-2). agent. Skin effects are delayed 12 hours or longer afterHN-2 is a liquid with a fruity odor in high concentrations. exposure. The protective mask and protective clothing

It is rated as somewh at more toxic than HN -1. HN -2 affects provide ad equate protection, but protection against largethe eyes in lower doses than do the other mustards. HN-2 droplets, splashes, and smears requires impermeablehas the greatest blistering power of the nitrogen mustards clothing. See Table 2-14. HN -2 is high ly unstable and is notin vapor form but is intermediate as a liquid blistering presently considered seriously as a chemical agent.

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Nitrogen Mustard (HN-3).HN -3 is the principal representative of the nitrogen

mustards because its vesicant properties are almost equalto those of HD. It also is the most st able in storage of thethree nitrogen mustards. Because of its low volatility, HN-3does not constitute a grave vapor hazard to the skin in open

air.HN -3 is a liquid th at has no od or in its pur e form. It isused as a delayed-action casualty agent that has a persist-

ency that is considerably longer than HD. Because it is notdetoxified, it is cumulative in the body. Most symptoms aredelayed for four to six hours, but in some cases tearing, eyeirritation, and intolerance to light d evelop imm ediatelyThe protective mask and protective clothing provide ade-quate protection, but protection against large droplets,

splashes, and smears requires impermeable clothing. SeeTable 2-15.

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Mustard-T Mixture (HT). essentially the same as those of HD, but HT is more stable,HT is a clear, yellowish, highly viscous liquid . It has a has a longer duration of effectiveness, and has a lower

garliclike odor similar to HD. It is a mixture of 60-percent freezing point than HD. Its low volatility makes effectiveHD a nd 40-percent T. T is a sulfur, oxygen, and chlorine vapor concentrations in the field difficult to obtain. HT hascompou nd similar in structure to HD. HT is used a s a a strong blistering effect. In addition to causing blisters, it

delayed-casualty agent, the persistency of which depend s irritates the eyes and is toxic when inhaled. See Table 2-16.on the munitions used and the weather. Properties are

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ArsenicalThe arsenical vesicants are a group of related com-

pounds in which arsenic is the central atom. In these agentsthe hydrogen atoms of arsine (A sH 3) are replaced byvarious organic groups and chloride or cyanide. The mainarsenical vesicants are lewisite (L), mustard-lewisite mix-ture (HL), and ph enyld ichloroarsine (PD).

All arsenical vesicants are colorless to brown liquids. Ingeneral, they are more volatile than mustard and have fruityto geraniumlike odors. They hydrolyze rapidly with waterto lose most of their vesicant properties. They are muchmore dangerous as liquids than as vapors. The liquids willcause severe bur ns of the eyes and skin, whale field con-centrations of vapors are unlikely to cause permanent sig-nificant injuries. Absorption of either vapor or liquid

through the skin in adequate dosage may lead to systemicintoxication or death . The rate of d etoxification in sublethalamounts is rapid. Immediate decontamination is necessaryto remove the liquid agents, but d econtamination is notnecessary for vapor unless pain is present. Inhaled vaporscause sneezing and may produce mild to moderate irrita-tion of the upper respiratory tract. Arsenical are less toxicthan other blister agents of military interest.

Lewisite (L).Lewisite is the principal arsenical of military interest. It

is a liquid with an odor like geraniums and very little odorwhen pure. It is used as a moderately delayed-actioncasualty agent w ith a p ersistency somew hat shorter thanthat of HD. When humidity is high, L hydrolyzes so rapidlythat it is difficult to maintain a concentration sufficient toblister bare skin. It produces effects similar to mustard.One main difference is that L produces immediate pain.

Lewisite warns of its presence by irritating the eyes andskin and has a rapid rate of action. Liquid L causes imme-diate burning sensation in the eyes and permanent loss ofsight if not decontaminated within one minute with largeamou nts of water. It has abou t the same blistering action

on the skin as does HD, even though the lethal dosage forL is much higher. Skin exposure to L produces an immedi-ate and strong stinging sensation to the skin; reddening ofthe skin starts within 30 minutes. Blistering does not appearuntil after about 13 hours. Skin burns are much deeper thanthose caused by HD. When inhaled in high concentrations,lewisite may be fatal in as short a time as 10 minutes. Thebody does not detoxify L. See Table 2-17.

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Mustard-Lewisite Mixture (HL).HL is a variable mix of HD and L that provides a mixture

of low freezing p oint for use in cold-weather op erations oras high-altitude spray. Table 2-18 lists the properties forthe mixture having the lowest possible freezing point, whichis 37-percent HD and 63-percent L by weight. Other mix-tures, such as 50:50, may be prep ared to meet p redeter-mined w eather conditions and have advan tages over the3763 mixture because of the increased HD content. Thepersistency of HL depends on the munitions used and theweather.

HL has a garliclike odor from its HD content. It is usedas a delayed-action casualty agent that is not detoxified in

the body. Contamination of the skin produces immediatestinging of the skin, which turns red within 30 minutes.Blistering, wh ich ten ds to cover the en tire area of theredd ened skin, is delayed for about 13 hours. Liquid HLcauses severe damage to eyes. The respiratory damage issimilar to that prod uced by mu stard, except in the mostsevere eases. In these eases fluid in the chest cavity mayaccompany fluid in the lungs. Liquid on the skin, as well asinhaled vapor, is absorbed and may cause poisoningthroughou t the bod y. These changes cause increased capil-lary permeability, which eventually causes shock and deathbecause of the loss of fluid from the bloodstream .

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Phenyldichloroarsine (PD) PD has an immediate effect on eyes and a delayed effecPD is a colorless liquid that is used as a delayed-action of 30 minutes to 1 hour on skin. PD blisters bare skin bucasualty agent. Persistency depends on the munitions used wet clothhg decomposes it immediately. The protectivand the weather. Although PD is classed as a blister agent, mask and protective clothing provide adequate protectionit also acts as a vom iting comp oun d. Limited u se of PD but protection against large droplets, splashes, and smearduring World War I did not indicate any marked supe- requires impermeable clothing. See Table 2-19.riority over the other vomiting compoun ds u sed.

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Ethyldichloroarsine (ED) Like other chemical agents containing arsenic, ED iED is a liquid with a fruity but biting and irritating odor. irritating to the respiratory tract and will produ ce lun

The Germ ans in trod uced ED (Table 2-20) in 1918 in an injury upon sufficient exposure. The vapor is irritating toeffort to produce a volatile agent with a short duration of the eyes, and the liquid may produce severe eye injury. Theffectiveness that would act more quicldy than diphosgene absorption of either vap or or liquid throu gh the skin ior mu stard an d th at wou ld last longer in its effects than sufficient amounts may lead to systemic poisoning or deathp hen yld ich loroar sin e (PD). Pr olon ged con tact w ith eith er liqu id or vap or blister s th

skin.

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Methyldichloroarsine (MD ) the liquid may severely injure the eyes. The absorption ofMD is similar to ethyldichloroarsine. Like L and the either vapor or liquid through the skin in sufficient amounts

other arsenical, MD causes immed iate irritation of th e may lead to systemic poisoning or death. Prolonged contacteyes and nose with blistering effects delayed for hours. MD with either liquid or vap or prod uces blistering of the skin.is irritating to the respiratory tract and produces lung injury Vapor concentrations required for blistering effect areupon sufficient exposure. The vapor irritates the eyes, and very difficult to attain in the field. See Table 2-21.

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UrticantsThe urticants are compounds with a d isagreeable, CX produ ces immediate pain varying from a m ild prick

penetrating odor. They cause an immediate, severe, burn-ing sensation; intense pain; and a feeling of numbness. Theyalso cause swelling. Chemically, urticants are halogenated

oximes. The most imp ortant of these is dichloroformoxime,also called p hosgen e oxime because of its similarity tophosgene. It may appear as a colorless, crystalline solid oras a liquid.

Phosgene oxime (CX) is one of the most v iolently irritat-ing substances know n. How ever, because of its extremeinstability, pu re CX is not likely to be u sed in militaryoperations.

ling to almost intolerable pain resembling a severe besting. It has been called nettle gas. It causes violent irritation to the mucous membranes of the eyes and nose. Even

at low tem peratures it has su fficient vapor p ressure tproduce tearing. When CX comes in contact with the skinthe area becomes pale in 30 seconds a nd a red ring su rround s the area. A wheal forms in about 30 minutes, thblanched area turns brow n in abou t 24 hou rs, and a scaforms in abou t a week. The scab usually falls off in about weeks. Itching may be present throughout healing, whichin some cases may be delayed beyond 2 months. See Tabl2-22.

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Section III. Incapacitating AgentsIncapacitating agen ts are chemicals that cause

physiological or mental effects that lead to temporary dis-ability. Unlike riot control agents with effects lasting onlya few minutes, incapacitating agents produce effects thatmay last for hours or days after exposure to the agent hasceased. Incapacitating agents differ from other chemicalagents in that the lethal dose is many times greater than theincapacitating dose. Thus, they do not seriously endangerlife except in cases exceeding many times the effective dose,

and they produ ce no permanent injury. Medical treatment,although not required, may speed recovery.Many comp ound s show potential as incapacitating

agents. However, in actual use the term refers to thoseagents that

Produce their effects mainly by altering or disruptingthe h igher regulatory activity of the central nervoussystem (CNS).Have effects that last hours or days rath er than beingmomentary or fleeting, as with tear agents.Do not seriously endanger life except at concentrationsgreatly exceeding the effective dose. They do notproduce permanent injury.

Allow recovery without treatment and without any per-manent effects.Are highl

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fm 3-9 potential military chemical and biological agents and compounds (1990) ww