types, nerve agents

1. CHEMICAL WEAPONS
Presented by:
Hafsa Abdul Ghuffar
Roll # 13-329

2. CONTENTS
• Why This Topic?
• Categories of Chemical Weapons
• Nerve Agents
a. Names
b. Synthesis of Sarin
c. Mode of Action
d. First Aid and treatment

3. WHY THIS TOPIC

4. CHEMICAL WEAPONS
• A toxic chemical contained in a delivery system, such as a bomb or
shell.
• According to Chemical Weapons Convention CWC, the term
chemical weapon is applied to any toxic chemical or its precursor that
can cause death, injury, temporary incapacitation or sensory irritation
through its chemical action.
• Munitions or other delivery devices designed to deliver chemical
weapons, whether filled or unfilled, are also considered weapons
themselves.

5. CATEGORIES
Military planners generally organize chemical into four groups:
• 1- nerve agents (such as sarin and VX)
• 2 -blister agents (such as mustard gas)
• 3-choking agents (such as chlorine and phosgene)
• 4- blood agents (such as hydrogen cyanide).

6. BLOOD AGENTS
• Volatile, flammable, usually colorless gasses attack by being
absorbed in blood
• Are cyanide or arsenic based
• act through inhalation
• Inhibit cells’ ability to transfer or utilize oxygen
Arsine

7. CHOCKING AGENTS
• Attack on lungs and eyes.
• Injure victims through inhalation and have a mild effect on
skin.
• Are gasses with specific odour.
• Chlorine gas and phosgene
• Low boiling points
Phosgene

8. BLISTERING AGENTS
• A blister agent, or vesicant, is a chemical compound that
causes severe skin, eye and mucosal pain and irritation.
• Chemically belong to these categories:
1. Sulfur mustards – A family of sulfur-based agents,
including mustard gas.
2. Nitrogen mustards – A family of agents similar to the sulfur
mustards, but based on nitrogen instead of sulfur.

9. BLISTERING AGENT
Sulfur Mustard
C4H8Cl2S

10. NERVE AGENTS
• phosphorus-containing organic chemicals
(organophosphates) that disrupt the mechanisms by which
nerves transfer messages to organs.

11. TABUN
• Tabun, O-ethyl dimethylamidophosphorylcyanide, with the
American denomination GA.

12. SOMAN
• • Soman, pinacolyl methylphosphonofluoridate, with the
American denomination GD, a moderately volatile substance
which can be taken up by inhalation or skin contact.

13. SARIN
• Sarin, isopropyl methylphosphonofluoridate, with the
American denomination GB, a volatile substance mainly
taken up through inhalation.

14. SYNTHESIS
• Reaction of methylphosphonyl difluoride with
isopropyl alcohol, which produces hydrofluoric
acid as a byproduct:

15. SYNTHESIS
• By reaction of equal quantities of methylphosphonyl
difluoride and methylphosphonic dichloride

16. NERVE AGENTS
SLUDGE Syndrome
• Salivation
• Lacrimation (tears flow)
• Urination
• Diaphoresis (sweating)
• Gastrointestinal motility
• Emesis (vomiting)

18. MODE OF ACTION
• irreversibly inhibit enzyme acetylcholinesterase.
• If nerve agent is inhaled poisoning effects start immediately
• If nerve agent gets into body via skin it might take 20-30
minutes for the symptoms to appear.

19. CHOLINERGIC SYNAPSE

20. MODE OF ACTION
Normal Reaction
• Enzyme-OH + CH3C(=O)-O-(CH2)2-N+(CH3)3 -------
Enzyme-O-C(=O)-CH3 + choline
• Enzyme-O-C(=O)-CH3 -----→ Enzyme-OH + CH3COOH
(hydrolysis)
Nerve Agent
• Enzyme-OH---X-P(=O)(R1)(-OR2) releases X- to give Enzyme-O-
P(=O)(R1)(-OR2)

21. TREATMENT
Reactivation Using Oxime
• The oxime (Pralidoxime in given example) attacks the P-O
bond
• operational enzyme and a phosphorylated oxime, which is
rapidly hydrolyzed to non-toxic products, are formed

22. TREATMENT
• Ageing
• In the "ageing" reaction, the phosphorylated enzyme is
dealkylated
• Enzyme-O-P(=O)(R1)(-OR2) reacts to give Enzyme-O-
P(=O)(R1)-OH
• The reaction is catalyzed by the enzyme itself
• Reaction may be extremely fast.
• Soman-inhibited acetylcholinesterase becomes "aged" within
a few minutes.