US 105mm M60 VX Chemical Projectile
Overview
The 105mm M60 VX Chemical Projectile is a chemical artillery round designed to deliver the nerve agent VX against enemy forces. VX is classified as a persistent nerve agent, combining the extreme lethality of nerve agents with long-lasting ground contamination similar to blister agents. This makes VX one of the most dangerous chemical warfare agents ever developed—extraordinarily toxic through both inhalation and skin contact, and capable of remaining hazardous for weeks under favorable conditions. The M60 VX was developed during the Cold War to provide U.S. divisional artillery with a capability for long-term contamination of enemy positions and denial of critical terrain. For EOD specialists, chemical demilitarization personnel, and humanitarian workers, the M60 VX represents one of the most hazardous munitions likely to be encountered, requiring the highest level of caution and specialized response.
EXTREME HAZARD WARNING: VX is among the most toxic substances known. A lethal dose can be absorbed through the skin in quantities invisible to the naked eye. Any suspected chemical munition must be treated with extreme caution. DO NOT approach, handle, or disturb suspected chemical ordnance. Evacuate the area immediately and contact qualified military chemical warfare/EOD specialists. Approach requires full Level A protection or military MOPP-4 with enhanced protection.
Country/Bloc of Origin
- Country: United States of America
- Development Period: Late 1950s-1960s (VX agent discovered in UK 1952; U.S. production began 1961)
- Production Period: 1961-1968 (primary production)
- Service Status: Declared obsolete; subject to Chemical Weapons Convention destruction requirements
- Historical Note: VX was discovered by British scientists at Porton Down; U.S. developed weaponized versions under technology sharing agreements
Ordnance Class
- Type: Artillery projectile (chemical ammunition)
- Primary Role: Delivery of persistent nerve agent for area denial and lethal casualties
- Agent Type: VX – persistent nerve agent
- Delivery Method: Fired from 105mm howitzers (M101, M102 series)
- Category: Chemical weapon; prohibited under Chemical Weapons Convention (CWC)
- Special Classification: VX is classified as a Weapon of Mass Destruction (WMD)
Ordnance Family/Nomenclature
Official Designation
- M60 VX – 105mm chemical projectile filled with nerve agent VX
Related Variants (Same Projectile Body)
- M60 GB – Filled with nerve agent GB (Sarin)
- M60 HD – Filled with blister agent HD (Mustard)
- M60 (training) – Inert training variant
Agent Designations
- VX – U.S./NATO designation
- Chemical Name: O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate
- CAS Number: 50782-69-9
- Other V-Agents: VE, VG, VM, VS (related compounds, similar properties)
Soviet Equivalent
- Vx (Soviet) – Soviet V-agent with slightly different formulation
- Often encountered in former Soviet/Russian weapons (different isomer than U.S. VX)
Chemical Weapons Convention Status
- Schedule 1 Chemical: Highest restriction category
- Prohibited: Manufacturing, stockpiling, and use banned under CWC
- Destruction Required: All signatory nations must destroy VX stockpiles
- Verification: Subject to international inspection protocols
Hazards
Primary Hazard: VX Nerve Agent
VX Characteristics:
- Oily, amber-colored liquid with low volatility
- Slight sulfur or machine oil odor
- Extremely persistent – remains hazardous for weeks to months
- Most lethal nerve agent – approximately 10 times more toxic than Sarin (GB) via skin absorption
- Primary route of exposure is skin contact (unlike GB which is primarily inhalation)
Extreme Toxicity:
- LD50 (skin): Approximately 10 mg (about the size of a small drop)
- LCt50 (inhalation): Approximately 10 mg·min/m³
- A single drop of VX absorbed through the skin can be lethal
- The median lethal dose is approximately 6-10 mg for a 70 kg adult
Routes of Exposure
- Skin Absorption: Primary route; VX penetrates intact skin readily; liquid is far more hazardous than vapor
- Inhalation: Dangerous, though less likely than GB due to low volatility
- Eye Contact: Extremely sensitive; causes miosis at very low concentrations
- Ingestion: Highly toxic orally (unlikely route in field)
Mechanism of Action
VX inhibits the enzyme acetylcholinesterase, preventing the breakdown of acetylcholine at nerve synapses. This causes:
- Continuous nerve signal transmission
- Muscle overstimulation leading to paralysis
- Death from respiratory muscle failure and respiratory center depression
Symptoms of Exposure
VAPEX (Vapor Exposure) – Eye and Respiratory Route:
- Miosis (pinpoint pupils) – earliest sign
- Rhinorrhea (runny nose)
- Chest tightness, difficulty breathing
- Progression to full nerve agent syndrome if severe
PERCUTANEOUS (Skin Exposure) – Primary VX Route:
- Delayed onset: May take 30 minutes to 18 hours for symptoms
- Local sweating and muscle twitching at exposure site
- Progressive systemic symptoms:
- Nausea, vomiting, diarrhea
- Generalized weakness
- Muscle fasciculations (twitching)
- Convulsions
- Loss of consciousness
- Respiratory failure and death
CRITICAL: The delay between skin exposure and systemic symptoms means victims may not immediately realize they’ve been exposed. By the time symptoms appear, a lethal dose may have been absorbed.
Persistence and Environmental Hazards
| Condition | Approximate Persistence |
|---|---|
| Hot, sunny, dry | Days to 1 week |
| Moderate temperature | 1-3 weeks |
| Cool, overcast | 3-6 weeks |
| Cold/winter | Weeks to months |
| Very cold/frozen | Months to over 1 year |
| Water contamination | Slowly hydrolyzes; weeks to months |
VX does not evaporate significantly under normal conditions. The primary hazard is direct contact with liquid agent. Vapor hazard exists in enclosed spaces or at elevated temperatures but is much lower than for GB.
Ordnance-Specific Hazards
- Bursting Charge: Explosive component for agent dispersal
- Fuze Hazards: Point-detonating fuze presents explosive hazard
- Extreme Leakage Danger: Any leakage creates lethal contact hazard; VX does not evaporate quickly, so leaked agent remains on surfaces
- Surface Contamination: VX adheres to surfaces and is difficult to remove
- Secondary Transfer: Contaminated personnel can transfer lethal doses to others through contact
Comparison with Other M60 Variants
| Property | M60 VX | M60 GB | M60 HD |
|---|---|---|---|
| Agent Type | Nerve | Nerve | Blister |
| Persistence | Very High | Low | High |
| Primary Route | Skin | Inhalation | Skin |
| Skin Toxicity | Extreme | Moderate | Delayed burns |
| Vapor Toxicity | High | Extreme | Moderate |
| Symptom Onset | 30 min-18 hrs | Seconds-minutes | 2-24 hours |
UXO/Chemical Ordnance Considerations
- Highest Risk Category: VX munitions represent the most dangerous chemical ordnance
- Any Leakage is Lethal: Even microscopic amounts on surfaces can kill
- Contamination Spread: Unlike GB, VX doesn’t evaporate; contamination persists and spreads through contact
- Aged Munitions: Corrosion may have released agent onto external surfaces
- Do Not Approach: Maximum standoff distance required; Level A protection mandatory
Immediate Action (Suspected Exposure)
- Immediately evacuate contaminated area
- Remove all clothing – bag separately; clothing is lethally contaminated
- Decontaminate skin – large quantities of water with soap, or 0.5% bleach solution
- Administer nerve agent antidotes if available:
- Atropine (blocks acetylcholine receptors)
- Pralidoxime/2-PAM (reactivates acetylcholinesterase if given early)
- Diazepam (controls seizures)
- Seek immediate medical attention – VX exposure is a medical emergency
Mark I or ATNAA autoinjector kits are designed for nerve agent casualties and should be used per training if available.
Key Identification Features
Dimensions
- Length: Approximately 400mm (15.7 inches) without fuze
- Diameter: 105mm (4.13 inches)
- Weight: Approximately 18 kg (39.7 lbs) complete
Color Scheme and Markings
Standard Chemical Ammunition Marking:
- Body Color: Gray
- Band: Green band (indicates chemical agent fill)
- Stenciling: Yellow markings
Specific Markings:
- “VX” stenciled in yellow
- “GAS” or “NERVE” marking
- Lot number and fill date
- Manufacturer codes
Warning Signs of Leakage:
- Oily residue (amber/honey-colored)
- Slight sulfur or petroleum odor
- Discoloration around seals or fill plug
- Even invisible residue can be lethal – assume contamination if suspected
Identification Challenges
All M60 chemical variants (GB, HD, VX) appear identical except for stenciled markings:
- Gray body
- Green band
- Yellow lettering
Weathered or corroded munitions may have illegible markings. In case of doubt, treat any gray projectile with green band as VX (the most hazardous variant) until positively identified by qualified specialists using detection equipment.
Material Composition
- Body: Steel
- Rotating Band: Copper or gilding metal
- Fill: VX nerve agent
- Burster: TNT or similar explosive
- Fuze Well: Threaded steel
Visual Identification Summary
| Feature | Description |
|---|---|
| Color | Gray |
| Band | Green |
| Markings | Yellow “VX,” “GAS” |
| Size | 105mm diameter |
| Distinctive | Same as M60 GB/HD externally |
Fuzing Mechanisms
Compatible Fuzes
- M557 Point-Detonating Fuze – Standard configuration
- M572 Point-Detonating Fuze – Alternative
- Other standard 105mm PD fuzes
Functioning Sequence
- Impact: Fuze strikes target
- Initiation: Firing pin activates detonator
- Detonation: Detonator initiates booster, then burster charge
- Dispersal: Burster ruptures projectile body, dispersing VX as droplets
Arming Sequence
- Bore Safety: Safe until projectile exits gun tube
- Setback Arming: Acceleration forces during firing
- Spin Arming: Rotation completes arming
- Armed State: Full arming at safe distance from gun
Superquick vs. Delay Settings
- Superquick (SQ): Airburst-type dispersal; maximizes droplet spread
- Delay: Ground burst; creates concentrated ground contamination
Safety Features
- Multiple arming requirements (setback + spin)
- Interrupter mechanisms
- Bore-safe design
UXO Fuze Hazards
- Assume fuze is armed and extremely sensitive
- Age degradation may have compromised safety mechanisms
- Any approach risks detonation AND chemical release
- Do not approach – chemical detection and disposal requires specialist teams
History of Development and Use
Discovery of V-Agents
VX and related “V-agents” were discovered during pesticide research:
- 1952: Dr. Ranajit Ghosh at Imperial Chemical Industries (ICI) in Britain discovered V-agents while researching organophosphate pesticides
- 1954: British shared V-agent information with the United States under defense technology agreements
- Late 1950s: U.S. began developing VX as a military weapon
U.S. VX Program
- 1961: VX production began at Newport Chemical Depot, Indiana
- 1961-1968: Primary production period
- Produced in bulk and filled into various munitions including:
- M60 105mm projectile
- M121/M121A1 155mm projectile
- M426 8-inch projectile
- M55 115mm rocket
- Land mines and spray tanks
Rationale for VX Development
VX offered tactical advantages not provided by existing agents:
- Combined lethality and persistence: More lethal than mustard, more persistent than GB
- Contact hazard: Created dangerous terrain requiring full protective equipment
- Area denial: Could deny critical terrain for extended periods
- Force multiplication: Even small amounts required extensive decontamination
Stockpile Storage
U.S. VX munitions were stored at multiple sites:
- Newport Chemical Depot, Indiana (primary production site)
- Tooele Army Depot, Utah
- Anniston Army Depot, Alabama
- Umatilla Chemical Depot, Oregon
- Pine Bluff Arsenal, Arkansas
- Johnston Atoll (Pacific storage)
Notable Incidents
Skull Valley Incident (1968):
- An F-4 Phantom releasing VX from aerial spray tanks during a test at Dugway Proving Ground had a malfunction
- VX drifted off-range into Skull Valley, Utah
- Approximately 6,000 sheep were killed
- Incident contributed to U.S. decision to halt chemical weapons production
- The accident remains the largest known VX release in U.S. history
Operation CHASE:
- Some chemical munitions, including VX, were disposed of through ocean dumping (1964-1970)
- Operation CHASE (Cut Holes And Sink ‘Em) disposed of obsolete munitions
- Practice discontinued due to environmental concerns
Chemical Weapons Convention
- 1993: CWC signed (entered into force 1997)
- U.S. Commitment: Destruction of all chemical weapons stockpile
- Destruction Methods: Incineration, neutralization at dedicated facilities
- Progress: Majority of VX stockpile destroyed; final destruction ongoing
Never Used in Combat by U.S.
The U.S. never employed VX in combat. However, VX has been used in assassinations and terrorist attacks:
- 1994-1995: Aum Shinrikyo cult in Japan produced VX and used it in assassination attempts
- 2017: Kim Jong-nam assassinated in Malaysia using VX
Current Status
- Destruction Ongoing: U.S. stockpile largely eliminated
- Legacy Sites: Former storage/production sites require ongoing environmental monitoring
- International Concern: Some nations suspected of retaining VX capability
- Verification Challenges: CWC implementation varies globally
Technical Specifications
| Specification | Detail |
|---|---|
| Caliber | 105mm |
| Projectile Length | ~400mm (15.7 in) without fuze |
| Weight (Complete) | ~18 kg (39.7 lbs) |
| Agent Fill | VX nerve agent |
| Fill Weight | Approximately 1.2 kg (2.6 lbs) |
| Burster Charge | TNT, ~340g |
| Muzzle Velocity | Variable by propelling charge |
| Maximum Range | ~11,000m (12,000 yds) |
Agent Specifications (VX)
| Property | Value |
|---|---|
| Chemical Name | O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate |
| Molecular Weight | 267.37 g/mol |
| Physical State | Oily liquid |
| Color | Amber/honey (clear when pure) |
| Odor | Slight sulfur/machine oil |
| Vapor Pressure | 0.0007 mmHg at 20°C (extremely low) |
| Boiling Point | 298°C (decomposes) |
| Freezing Point | -39°C |
| Persistence | Weeks to months |
| Solubility | Slightly soluble in water; miscible with organic solvents |
| Skin LD50 | ~10 mg (lethal dose) |
| Inhalation LCt50 | ~10 mg·min/m³ |
Comparative Toxicity
| Agent | Skin LD50 | Inhalation LCt50 |
|---|---|---|
| VX | ~10 mg | ~10 mg·min/m³ |
| GB (Sarin) | ~1,700 mg | ~35-70 mg·min/m³ |
| HD (Mustard) | ~100 mg/kg | ~1,500 mg·min/m³ |
VX is approximately 170 times more toxic than GB through skin absorption.
Contamination Characteristics
- Primary Hazard: Contact with liquid agent
- Vapor Hazard: Low under field conditions (except enclosed spaces)
- Decontamination: Requires active decontamination; does not weather naturally
- Cross-Contamination: Easily transferred to unprotected surfaces and personnel
Frequently Asked Questions
Q: Why is VX considered more dangerous than Sarin (GB) even though both are nerve agents? A: VX is more dangerous than GB for several reasons: (1) Skin absorption – VX is approximately 170 times more toxic than GB through the skin, meaning even tiny droplets are lethal; (2) Persistence – VX remains on surfaces for weeks to months, creating an ongoing contact hazard, while GB evaporates in hours; (3) Delayed symptoms – Skin exposure to VX may not produce symptoms for 30 minutes to 18 hours, allowing a lethal dose to be absorbed before the victim is aware; (4) Difficult decontamination – VX adheres to surfaces and requires active decontamination, while GB largely decontaminates naturally through evaporation. While GB creates a more immediate vapor threat and is often considered more dangerous for sudden mass casualties, VX’s persistence and extreme skin toxicity make it exceptionally dangerous for contaminated area operations.
Q: How can first responders detect VX contamination given its low volatility and near-invisible appearance? A: Detection of VX is challenging due to its low vapor pressure and clear-to-amber color: (1) Chemical detection equipment – M8/M9 paper detects liquid V-agents through color change; CAM (Chemical Agent Monitor) and similar electronic detectors can identify VX vapor but require elevated temperatures or enclosed space conditions; (2) Environmental indicators – dead animals or insects, unexplained casualties with nerve agent symptoms, oily residue on surfaces; (3) Munition identification – presence of gray/green-banded munitions indicates possible chemical threat; (4) Symptoms in casualties – miosis, muscle twitching, respiratory distress appearing without obvious cause. The key challenge is that VX may be present in lethal concentrations without registering on vapor-based detectors. Liquid VX detection through M9 paper or surface sampling is essential for confirming contamination. When chemical munitions are suspected, assume VX contamination until proven otherwise.
Q: What is the correct decontamination procedure for personnel exposed to VX? A: Immediate decontamination is critical for survival: (1) Immediately remove all clothing – contaminated clothing can continue to release agent; bag and isolate; (2) Physical removal first – blot (don’t rub) any visible liquid with absorbent material; (3) Reactive decontamination – apply 0.5% sodium hypochlorite (bleach solution) or Reactive Skin Decontamination Lotion (RSDL) to all potentially exposed skin; (4) Water flush – flush with large quantities of water and soap after reactive decontamination; (5) Eye irrigation – flush eyes with water for at least 15 minutes; (6) Antidote administration – atropine and pralidoxime (2-PAM) autoinjectors should be administered per training; (7) Medical evacuation – all VX exposures require hospital care. Speed is critical – decontamination within 1-2 minutes of exposure dramatically improves survival. The RSDL kit is the current standard for reactive decontamination and is more effective than bleach for VX.
Q: Why does VX have delayed symptoms compared to Sarin, when both are nerve agents acting on the same target? A: The delayed symptoms from VX skin exposure relate to absorption kinetics: (1) Rate of absorption – VX must penetrate the skin to enter the bloodstream, which takes 30 minutes to several hours depending on location, skin condition, and dose; (2) Lipophilicity – VX’s oil-like properties mean it adheres to and slowly penetrates the lipid layers of skin; (3) Target organs – after absorption, VX must distribute to the central nervous system and neuromuscular junctions to cause symptoms; (4) Contrast with vapor – inhalation or eye exposure to VX vapor causes immediate symptoms (miosis, rhinorrhea) because the agent directly contacts neural tissue. GB vapor symptoms are immediate because GB is highly volatile and rapidly absorbed through the lungs. This delay makes VX particularly insidious—a soldier could receive a lethal skin exposure, feel normal for hours, then rapidly deteriorate as the systemic dose accumulates.
Q: What tactical advantages did VX provide that justified its development when Sarin already existed? A: VX filled tactical requirements that Sarin could not: (1) Area denial – VX contamination could deny critical terrain (bridges, command posts, supply routes) for days to weeks, similar to mustard but with far greater lethality; (2) Skin hazard – unlike GB’s primarily respiratory threat, VX required full-body protection; troops in protective masks but without chemical suits remained vulnerable; (3) Decontamination burden – any contaminated equipment required extensive decontamination before safe use, degrading enemy combat effectiveness; (4) Combined effects – VX provided both immediate casualties (from concentrated exposures) and sustained hazard (from persistent contamination). Essentially, VX combined the lethality of GB with the persistence of mustard, creating an agent that was both immediately lethal and created long-lasting hazardous terrain.
Q: What are the specific challenges of destroying VX munitions compared to other chemical weapons? A: VX destruction presents unique challenges: (1) Extreme toxicity – any leak during handling or processing can cause fatalities, requiring the highest level of worker protection; (2) Oily consistency – VX adheres to container walls, making complete drainage difficult (“heel” residue); (3) Hydrolysis challenges – VX hydrolyzes slowly and may produce toxic byproducts; neutralization requires specific conditions; (4) Incineration requirements – higher temperatures and longer residence times needed compared to GB; (5) Environmental monitoring – surrounding communities require extensive air monitoring and emergency preparedness. The U.S. has used both incineration (at TOCDF, ANCDF) and neutralization (at Newport and other sites) for VX destruction, with each method having advantages and challenges. The neutralization of VX at Newport Chemical Depot, which produced bulk VX, required extensive process development.
Q: How would a VX attack differ tactically from a Sarin attack, from the defender’s perspective? A: The defensive challenges are markedly different: Sarin attack – immediate vapor hazard requiring respiratory protection; detect-and-mask response must occur in seconds; contamination self-decontaminates within hours; casualties are immediate. VX attack – primarily contact hazard; full-body protection required for any movement in contaminated area; contamination persists for weeks; casualties may appear hours after attack; all equipment must be decontaminated or abandoned. For defenders, VX forces prolonged operations in full protective equipment (extremely degrading to combat effectiveness), requires extensive decontamination capability, and effectively denies terrain until thorough decontamination is completed. VX changes the fight from “survive the initial attack and continue” to “everything in this area is lethally contaminated for the foreseeable future.”
Q: What was the significance of the Skull Valley incident, and what changes resulted? A: The Skull Valley incident in March 1968 was a watershed moment for the U.S. chemical weapons program: (1) What happened – An F-4 aircraft releasing VX during a test at Dugway Proving Ground experienced an equipment malfunction; wind carried VX off-range into Skull Valley; approximately 6,000 sheep died from exposure; (2) Immediate impact – The Army initially denied responsibility but evidence was overwhelming; public outcry was significant; (3) Program changes – The incident contributed to President Nixon’s decision in 1969 to unilaterally renounce first use of chemical weapons and halt offensive chemical weapons production; (4) Policy shifts – Led to increased environmental restrictions on testing, enhanced safety protocols, and eventually the decision to destroy the stockpile rather than maintain it; (5) Long-term significance – The incident demonstrated that chemical weapons posed risks not just to enemies but to American civilians and military personnel, undermining the case for maintaining the capability.
Q: How does the Russian/Soviet VX variant differ from U.S. VX, and why does this matter for identification? A: The Soviet Union developed its own V-agent, sometimes called “Russian VX” or “R-VX” (also designated VR or Substance 33), which has a different chemical structure than U.S. VX: (1) Structural difference – Russian VX uses an isobutyl group where U.S. VX uses ethyl; (2) Property differences – Slightly different volatility, toxicity, and persistence characteristics; (3) Detection implications – Some detection equipment calibrated for U.S. VX may respond differently to Russian VX; (4) Medical implications – While both are nerve agents responding to the same antidotes, the kinetics may differ slightly; (5) Identification importance – For EOD/humanitarian demining personnel, encountering V-agent munitions in former Soviet states, client nations, or conflict zones may involve Russian VX rather than U.S. VX. The distinction matters for threat assessment and confirms the origin of the munition. Both are extraordinarily lethal persistent nerve agents requiring the same protective measures.
SAFETY NOTICE: This lesson is intended for educational and training purposes. All ordnance should be considered dangerous until proven safe by qualified personnel. Unexploded ordnance should never be handled by untrained individuals—report findings to military or law enforcement authorities.