chemical agents - Faculty Server...

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Chemical Agents

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Chemical Warfare – Historical Perspective

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Chlorine (Cl ): “A new form of warfare”

Logistics: 5,730 90-lb cylinders buried in concealment along a 6-km front; 160 tons of gas were manually released when the wind

Result: 5,000 dead, 10,000 wounded.was favorable.

Use: by Germany against Allied troops on 22 April 1915 at 5 pm near Ypres, Belgium.

Choking gases and lung irritantsCW agents that irritate the respiratory system causing formation of water in the

lungs, resulting in death from lack of oxygen

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Phosgene (carbonyl chloride, COCl )

Use: At 5:30 am on 19 December 1915, the Germans attacked at Ypres (again) using phosgene in artillery shells.

Results: Panic and disruption as men were caught unawares. 1,069 men gassed; 116 dead.At the Somme in June 1916, the

Allies used both chlorine and phosgene: men, vegetation, insects, and animals were wiped out.

Over the next 19 months, the British discharged over 1,500 tons of phosgene.

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Blister agents (vesicants)CW agents that affect eyes, lungs, and skin, causing formation of

large blisters

Use: On 12 July 1917, about 10 pm, at Ypres, Belgium, the Germans shelled the British with 77 and 105 mm gas shells.

Result: Initial effect was just sneezing; within hours eye irritation, vomiting, and blisters appeared.

Gas attack by artillery in WW1

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Growing use of CW in WWIYear Amount of gas discharged in tons

1915 3,8701916 16,5351917 38,635

1918 65,160

J. B. S. Haldane, CallinicusA Defence of Chemical Warfare,Kegan Paul: London, 1925, pp. 28-38.

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Blood agentsCW agents that interfere with the body’s ability to transport oxygen

in the blood stream

Poisons that block oxygen use or uptake from the blood, causing asphyxiation.

Hydrogen cyanide(HCN, prussic acid): Liquid at room temperature, but evaporates rapidly. Used in Zyklon B made by IG Farben for use in German WW2 extermination camps. Unstable due to rapid polymerization and thus considered unsuited today for CW.

Unconfirmed reports:1980s, HCN used by Syria against uprising in Hama; 1988, Iraqi attack on Kurdish town of Halabja; Shahabad, Iran, during the Iran-Iraq war.

Japanese WW2 HCN grenade

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Union Carbide Accident

Bhopal, India Dec. 3, 1984

Methyl Isocyanate (MIC)

8,000 people dead within days

20,000 dead in the years following

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Novichok nerve agents1990s

Laser detectionImproved gas masks(protection, fit, comfort)

Binary munitions1980s

1970s

Nerve gas alarmGas mask w/ water supplyAerodynamicV-series nerve agents1960s

1950s

Protective ointment (mustard)Collective protection

Gas mask w/ Whetlerite

Missile warheadsSpray tanks1940s

Blister agent detectorsColor change paperAircraft bombsG-series nerve agents1930s

CC-2 clothingProjectiles w/ central bursters1920s

Gas maskRosin oil clothing

Chemical shellsLewisite1910s

SmellWind dispersal

ChlorineChloropicrin

PhosgeneMustard gas

1900s

DetectionProtectionDisseminationAgents

Chemical Warfare Technology Timeline

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Advantages / Disadvantages of Chemical Agents

Advantages• Immediate effect

• Easily spread

• Tie up resources

• Psychological impact

Disadvantages• Requires large quantities

• Production & deployment hazardous to terrorist

• Less difficult to prepare for

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Chemical warfare agents

• A chemical used in warfare is called a chemical warfare agent (CWA), and is usually gaseous at room temperature or is a liquid that evaporates quickly.

• Such liquids are said to be volatile or have a high vapor pressure.

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Persistency

• All chemical weapon agents are classified according to their persistency, a measure of the length of time that a chemical agent remains effective after dissemination.

• Chemical agents are classified as persistentor nonpersistent.

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Persistency

• Agents classified as nonpersistent lose effectiveness after only a few minutes or hours.

• Purely gaseous agents such as chlorine are nonpersistent, as are highly volatile agents such as sarin and most other nerve agents.

• Tactically, nonpersistent agents are very useful against targets that are to be taken over and controlled very quickly.

• Generally speaking, nonpersistent agents present only an inhalation hazard.

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Persistency

• Persistent agents tend to remain in the environment for as long as a week, complicating decontamination.

• Defense against persistent agents requires shielding for extended periods of time.

• Non-volatile liquid agents, such as blister agents and the oily VX nerve agent, do not easily evaporate into a gas, and therefore present primarily a contact hazard.

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CLASSES OF CHEMICAL AGENTS

Choking Blood Blister Nerve

Toxic

CS CR CN OC

Incapacitating

Chemical Agents

Chemical warfare agents are organized into several categories according to the manner in which they affect the human body. Thenames and number of categories varies slightly from source to source, but in general, types of chemical warfare agents are as follows:

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IRRITANTS OR RIOTCONTROL AGENTS

• CS (tear gas)

• SR (tear gas)

• CN (mace)

• OC (pepper spray)

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Chemical Agents – Preview

Toxic•• ChokingChoking (pulmonary)

agents• “BloodBlood” agents

•• BlisterBlister agents• Nerve agents.

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Chemical Agents –Choking (Pulmonary) Agents

• A pulmonary, or lung agent, is a chemical that damages the membranes in the lung

• The plasma from the blood leaks into the alveoli filling them with fluid and prevents air from entering

• The victim dies from “dry-land drowning”.

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CHOKING AGENTS

• Phosgene (CG)

– Odor: newly mown hay

• Chlorine (Cl2)

– Odor: swimming pool

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CHOKING AGENTS

Phosgene (CG) and Chlorine (Cl2) Odor Phosgene: newly mown hay;

Chlorine: swimming pool Persistency Minutes to hours Form Gas, heavier than air Rate of action Immediate, symptoms will get worse with

time Route of entry Respiratory Symptoms Coughing, choking, tightness of the chest Hazard Respiratory; skin Self-Aid Leave contaminated area Decontamination Flushing with water and aeration

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Chemical Agents –Choking (Pulmonary) Agents

Phosgene• Smells like mown

hay• Inhalation threat

• Cough and tightness in chest

• No antidote

Chlorine• Smells like bleach• Inhalation threat• Cough and tightness

in chest• No antidote.

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Choking Agents

• Signs & symptoms• Coughing• Choking• Chest tightness• Odors: chlorine,

bleach, swimming pools, or newly-mown hay or grass

• Routes of exposure• Inhalation

• Skin absorption

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Chemical Agents –“Blood” Agents

Cyanide• Hydrogen cyanide

(ac)• Cyanogen chloride

(ck)

• Smells like?

Almonds.

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BLOOD AGENTS Hydrogen Cyanide (AC) and Cyanogen

Chloride (CK)

Odor Bitter almonds

Persistency Minutes to hours

Form Hydrogen Cyanide: Gas, lighter than air Cyanogen Chloride: Gas, heavier than air

Rate of action Rapid (seconds)

Route of entry Respiratory

Symptoms Gasping for air, frothing

Hazard Respiratory

Self-Aid Leave contaminated area

Decontamination Aeration

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Chemical Agents –“Blood” Agents

Effects of cyanide• Small amount

• No effects unless lengthy exposure• Medium amount

• Dizziness, nausea, feeling of weakness• Large amount

• Loss of consciousness, convulsions, and breathing stops.

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Blood Agents

• Signs & symptoms• Increased

respirations• Dizziness• Headaches• Cardiac symptoms• Odors: burnt

almonds or peach kernels

• Routes of exposure• Inhalation• Skin absorption• Ingestion• Injection

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Chemical Agents –Blister Agents

Mustard (H)Lewisite (L)Phosgene Oxime (CX).

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Vesicants (Blister Agents)• Signs & symptoms

• Reddening of skin• Convulsions

• Respiratory failure• Sluggish

• Apathetic• Lethargic• Fever

• Routes of exposure

• Inhalation

• Skin absorption

• Ingestion

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Chemical Agents –Blister Agent

Mustard• No immediate physical

signs • Redness of skin after 4-8

hours

• Absorbed through eyes, skin, and airways

• Blisters appear.

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BLISTER AGENTS

• Mustard (H)– Odor: garlic

• Lewisite (L)– Odor: geraniums

• Phosgene oxime (CX)– Odor: irritating

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BLISTER AGENTS Mustard (H), Lewisite (L), and Phosgene

Oxime (CX)

Odor Mustard: garlic Lewisite: geraniums Phosgene oxime: irritating

Persistency Hours to days Form Mustard and lewisite: liquid, vapor, heavier

than air; phosgene oxime: solid Rate of action Rapid

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BLISTER AGENTS (con’t) Mustard (H), Lewisite (L), and Phosgene

Oxime (CX)

Route of entry Skin, inhalation, eyes Symptoms Mustard: no immediate pain

Lewisite and Phosgene Oxime: immediate pain, burning eyes, cough, skin blisters after 6-24 hours

Hazard Respiratory and skin Self-Aid Immediate removal; flush with water; .5%

bleach Decontamination Removal; flush with water; .5% bleach

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Lewisite (L)• Immediate effect• Very irritating; Pain on

contact• Intended for use in WWI

but not used until WWII• Tissue damage evident

in minutes (gray skin)

Phosgene Oxime• Colorless and produces

intolerable pain• Upon contact skin becomes

blanched with red ring around

• Tissue turns brown and scab forms.

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Chemical Agents –Nerve Agents

Tabun (GA)Sarin (GB)Soman (GD)VX.

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Nerve Agents

• Signs & symptoms• Pinpoint pupils• Runny nose• Difficulty breathing• Loss of

consciousness• Convulsions /

seizures• Sweating• Nausea / vomiting

• Routes of exposure• Inhalation• Skin absorption• Ingestion

• Injection

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Chemical Agents –Nerve Agents

Effects of nerve vapor exposure• Small pupils• Runny nose (Rhinorrhea)• Shortness of breath.

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NERVE AGENTS

Tabun (GA), Sarin (GB), Soman (GD), VX (VX)

Odor Tabun and Sarin: Fruity Soman: Camphor VX: Sulfur

Persistency Tabun and Sarin: Minutes to hours Soman: Hours VX: Hours to days

Form Tabun, Sarin, Soman: Liquid; vapor: heavier than air VX: Liquid

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NERVE AGENTS (con’t) Tabun (GA), Sarin (GB), Soman (GD), VX (VX)

Route of entry Skin, inhalation, eyes

Symptoms Pinpointing pupils; dimness of vision;

runny nose; drooling; difficult breathing;

tightness in chest; muscle twitching

Hazard Respiratory and skin

Self-Aid Atropine; 2-pam chloride

Decontamination Removal; flush with water, dilute bleach

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Comparative Toxicities

Cyanogen Chloride

PhosgeneHydrogen Cyanide

Mustard

Sarin - 200X

VX - 600X

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100

200

300

400

500

600

700

Chlorine Gas as a baseline

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Steps to chemical warfare

1.Acquisition of CW materials

2.Production of CW agents

3.Delivery of CW weapons

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Acquisition of CW materialsDevelop from raw materials (or precursors), purchase outright, or

combine “home-grown” with “store-bought.”

Many precursors to CW weapons are materials with legitimate commercial uses:

CompoundThiodiglycolPhosphorus trichlorideSodium cyanideMethylphosphonicdifluoride

Commercial usePlastics, textile dyes, ink Plasticizers, insecticides Dyes, pigments, metal hardening Organic synthesis

CW useMustardG-series GA, AC, CK VX, GB, GD

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Production of CW agents

• Synthesis in small batch quantities in a pilot plant to solve technical difficulties in chemistry, scale-up, handling.

• Use of standard chemical engineering equipment (reactors, distillations apparatus, heat exchangers, pumps, valves, filters, etc.). Obtaining and maintaining this equipment may be problematic.

• Specialized equipment (e.g., glass lines or steel reactors) may be needed to handle corrosives.

• Making the product into a suitable form to use as a weapon (“weaponizing”) usually requires some technical expertise. Issues include: design of unitary or binary CWs; stability; handling; storage; dissemination as liquid, powder, spray, or aerosol; dispersal; thermal and shock lability.

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Delivery of CW agents

The effectiveness of CW agents is influenced by a combination of the choices made in delivery and environmental conditions.

•CW delivery:point source with munitions; line source with sprayer.

•Form:Liquid, aerosol, or vapor.

•Atmospheric conditions:temperature (and patterns of temperature), time of day;wind, sun, rain, altitude.

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CW terrorism1974: Muharem Kerbegovic was arrested in Los Angeles after mailing toxic

material to a Justice of the Supreme Court and threatening to kill the president with nerve gas

1991: German authorities thwarted a neo-Nazi plot to pump hydrogen cyanide into a synagogue.

1992: the FBI arrested two members of the Patriots Council in Minnesota for possession of less than one gram of ricin, under the Biological Weapons Anti-Terrorism Act of 1989.

1993: First World Trade Center Bombing led by Ramsi Yousef. The use of cyanide was considered, but delivery was considered too expensive.

1994: Aum Shinrikyo, an apocalyptic religious cult based in Japan, used a refrigerated truck to spray sarin on several magistrates who were to rule against them in a legal dispute. The judges survived, 7 bystanders were killed, and 144 were seriously injured.

1995: Attack on Tokyo subway by Aum Shinrikyo used sarin. 12 people killed, 1,000 injured in 16 stations. Would have been worse if they had not diluted their sarin stock with acetonitrile.

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The future threat

The level of knowledge required to manufacture chemical weapons is on the order of a competent organic chemistry graduate student—much less knowledge than required for biological weapons.

Most of the starting materials and equipment can be commercially purchased without notice or alarm.

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The future threat

The large amounts of industrial chemicals manufactured and shipped (e.g., chlorine) offer themselves as low-tech weapons of opportunity and terror.

“Obsolete” for the strategic or tactical military operations is not the same as unusable for terrorism.

The events of 11 September 2001 show that even “ordinary” items of our high-tech world can be transformed into weapons.

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Chemical Agents – Review

Toxic•• PulmonaryPulmonary

•• BloodBlood

•• BlisterBlister

•• NerveNerve.

Incapacitating• CN (mace)• Cs• Capsaicin

(pepper-spray)

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KEY POINTS

Chemical agents are super toxic, but—

• They can be detected

• One can protect oneself

• There are first aid measures

• They can be decontaminated

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