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Material Safety Data Sheet -- Lethal Nerve Agent VX

Section I: General Information
Section II: Composition
Section III: Physical Data
Section IV: Fire and Explosion Data
Section V: Health Hazard Data
Section VI: Reactivity Data
Section VII: Spill, Leak and Disposal Procedures
Section VIII: Special Protection Information
Section IX: Special Precautions
Section X: Transportation Data
Addendum A: Physiological Effects
Addendum B: First Aid Procedures

Section I: General Information

MANUFACTURER'S NAME: Department of the Army


U.S. Army Armament, Munitions and Chemical Command
Chemical Research, Development and Engineering Center
Aberdeen Proving Ground, MD 21010-5423

CAS REGISTRY NUMBER: 50782-69-9, 51848-47-6, 53800-40-1, 70938-84-0

CHEMICAL NAME: Phosphonothioic acid, methyl-, S-(2bis(1-methylethylamino)ethyl) 0-ethyl ester



CHEMICAL FAMILY: Sulfinated organophosphorus compound

FORMULA: C11 H26 N 02 P S


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Section II: Composition

NAME                          BY WEIGHT      EXPOSURE LIMIT 

 VX            C11H26N02PS    100           .00001 mg/m3

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Section III: Physical Data


VAPOR PRESSURE (mm Hg): 0.0007 @ 25 DEG C



APPEARANCE AND ODOR: Colorless to straw colored liquid & odorless, similar in appearance to motor oil.

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Section IV: Fire and Explosion Data

FLASHPOINT: 159 DEG C (McCutchan-Young)

FLAMMABILITY LIMITS: (% by volume): Not available



EXTINGUISING MEDIA: Water mist, fog, foam, CO2 - Avoid using extinguishing methods that will cause splashing or spreading of the VX.


All persons not engaged in extinguishing the fire should be immediately evacuated from the area. Fires involving VX should be contained to prevent contamination to uncontrolled areas. When responding to a fire alarm in buildings or areas containing agents, firefighting personnel should wear full firefighter protective clothing (without TAP clothing) during chemical agent firefighting and fire rescue operations.

Respiratory protection is required. Positive pressure, full facepiece, NIOSH-approved self contained breathing apparatus (SCBA) will be worn where there is danger of oxygen deficiency and when directed by the fire chief of chemical accident/incident (CAI) operations officer. The M9 or M17 series mask may be worn in lieu of SCBA when there is no danger of oxygen deficiency. In cases where firefighters are responding to a chemical accident/incident for rescue/reconnaissance purposes vice firefighting, they will wear appropriate levels of protective clothing (see Section 8).

Do not breathe fumes. Skin contact with V-agents must be avoided at all times. Although the fire may destroy most of the agent, care must still be taken to assure the agent or contaminated liquids do not further contaminate other areas or sewers. Contact with VX or VX vapors can be fatal.


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Section V: Health Hazard Data


The suggested permissible airborne exposure concentration of VX for an 8 hour workday or a 40 hour work week is an 8 hour time weighted average (TWA) of 0.00001 mg/m3 (9 x 10-7 ppm). This value is based on the TWA of VX as proposed in the USAEHA Technical Guide No. 169, "Occupational Health Guidelines for the Evaluation and Control of Occupational Exposure to Nerve Agents GA, GB, GD, and VX." To date, however, the Occupational Safety and Health Administration (OSHA) has not promulgated permissible exposure concentration for VX.

VX is not listed by the International Agency for Research on Cancer (IARC), American Conference of Governmental Industrial Hygienists (ACGIH), Occupational Safety and Health Administration (OSHA), or National Toxicology Program (NTP) as a carcinogen.


VX is a lethal anticholinergic agent with the median dose in man being: LC50 (skin) = 0.135 mg/kg; ID50 (Skin) - 0.07 - 0.71 mg/kg; LCt50 (inhalation) = 30 mg min/m3; LCt50 (inhalation) - 30 mg min/m3; LCt50 (inhalation) - 24 mg min/m3.

  1. One to several minutes after overexposure to airborne VX the following acute symptoms appear:

    1. LOCAL EFFECTS (lasting 1-15 days, increases with dose)

      1. On eyes: Miosis (constriction of pupils); redness, pressure sensation on eyes.
      2. By inhalation: Rhinorrhea (runny nose), nasal congestion, tightness in chest, wheezing, salivation, nausea, vomiting

    2. SYSTEMIC EFFECTS (increases with dose): By inhalation - excessive secretion causing coughing/breathing difficulty; salivation and sweating; vomiting, diarrhea; stomach cramps; involuntary urination/defecation; generalized muscle twitching/muscle cramps; CNS depression including anxiety, restlessness, giddiness, insomnia, excessive dreaming and nightmares. With more severe exposure, also headache, tremor, drowsiness, concentration difficulty, memory impairment, confusion, unsteadiness on standing or walking, and progressing to death.

  2. After exposure to liquid VX, the following acute symptoms appear:

    1. Local Effects:

      1. On eyes: Miosis, redness, pressure sensation on eyes.
      2. By ingestion: salivation, anorexia, nausea, vomiting, abdominal cramps, diarrhea, involuntary defecation, heartburn.
      3. On skin: Sweating, muscle twitching
    2. Systemic Effects: Similar to generalized effects from exposure to airborne VX.

  3. Chronic overexposure to VX causes forgetfulness, thinking difficulty, vision disturbances, muscular aches/pains. Although cer-organophosphate pesticides have been shown to be teratogenic in animals, these effects have not been documented in carefully controlled toxicological evaluations for VX.


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Section VI: Reactivity Data

STABILITY: Relatively stable at room temperature. Unstabilized VX of 95% purity decomposed at a rate of 5% a month at 71 deg. C.


During basic hydrolysis of VX up to about 10% of the agent is converted to EA2192 (diisopropylaminoethyl methylphosphonothioic acid). Based on the concentration of EA2192 expected to be formed during hydrolysis and its toxicity (1.4 mg/kg dermal in rabbit at 24 hours in a 10/90 wt% ethanol/water solution), a Class B poison would result.

The large scale decon procedure, which uses both HTH and NaOH, destroys VX by oxidation and hydrolysis. Typically the large scale product contains 0.2 - 0.4 wt% EA2192 at 24 hours. At pH 12, the EA2192 in the large scale product has a half-life of about 14 days. Thus the 90 day holding period at pH 12 results in about a 64-fold reduction of EA2192 (six half-lives). This holding period has been shown to be sufficient to reduce the toxicity of the product below that of a Class B poison.

Other less toxic products are ethyl methylphosphonic acid, methylphosphinic acid, diisopropylaminoethyl mercaptan, diethyl methylphosphonate, and ethanol.

The small scale decontamination procedure uses sufficient HTH to oxidize all VX thus no EA2192 is formed.


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Section VII: Spill, Leak and Disposal Procedures

STEPS TO BE TAKEN IN CASE MATERIAL IS RELEASED OR SPILLED: If leak or spills occur, only personnel in full protective clothing (see Section 8) will remain in area. In case of personnel contamination, see Section V "Emergency and First Aid Instructions." Spills must be contained by covering with vermiculite, diatomaceous earth, clay or fine sand. This containment is followed by the following treatment.

RECOMMENDED LABORATORY PROCEDURES (For Quantities less than 50 grams):

If the active chlorine of the Calcium Hypochlorite (HTH) is at least 55 percent, then 80 grams of a 10 percent slurry is required for each gram of VX. Proportionally more HTH is required if the chlorine activity of the HTH is lower than 55 percent. The mixture is agitated as the VX is added and the agitation is maintained for a minimum of one hour. If phasing of the VX/decon solution continues after 5 minutes, an amount of denatured ethanol equal to a 10 wt percent of the total agent/decon shall be added to assist miscibility. NOTE: Ethanol should be minimized to prevent the formation of a hazardous waste.

Upon completion of the one hour agitation the decon mixture shall be adjusted to a pH between 10 and 11. Conduct general area monitoring to confirm that the atmospheric concentrations do not exceed the airborne exposure limit (see Secions 2 and 8).

RECOMMENDED FIELD PROCEDURES (For quantities greater than 50 grams):

NOTE: These procedures can only be used with the approval of the CRDEC Safety Officer.

An alcoholic HTH mixture is prepared by adding 100 milliliters of denatured ethanol to a 900 milliliter slurry of 10 percent HTH in water. This mixture should be made just prior to use since the HTH can react with the ethanol. Fourteen grams of alcoholic HTH solution is used for each gram of VX. Agitate the contaminaton mixture as the VX is added. Continue the agitation for a minimum of one hour. This reaction is reasonable exothermic and evolves substantial off gassing. The evolved reaction gases should be routed through a decontaminate filled scrubber prior to release through filtration systems.

After completion of the one hour minimum agitation, 10 percent Sodium Hydroxide is added in a quantity equal to that necessary to assure that a pH of 12.5 is maintained for a period not less than 24 hours. Hold the material at a pH between 10 ad 12 for a period not less than 90 days to ensure that a hazardous intermediate material is not formed.

After sealing the head, the exterior of the drum shall be decontaminated and then labeled IAW EPA and DOT regulations. All leaking containers shall be overpacked with vermiculite placed between the interior and exterior containers. Decontaminate and label IAW EPA and DOT regulations. Dispose of the material IAW waste disposal methods provided below. Conduct general area monitoring to confirm that the atmospheric concentrations do not exceed the airborne exposure limit (see Section 2 and 8).

If the alcoholic Calcium Hypochlorite (HTH) mixture is not available then the following decontaminants may be used instead and are listed in the order of preference: Decontamination Solution No. 2 (DS2), Supertropical Bleach Slurry (STB), and Sodium Hypochlorite.

WASTE DISPOSAL METHOD: Open pit burning or burying of VX or items containing or contaminated with VX in any quantity is prohibited. The detoxified VX (using procedures above) can be thermally destroyed by incineration in an EPA approved incinerator in accordance with appropriate provisions of Federal, state and local RCRA regulations. NOTE: Some states define decontaminated surety material as a RCRA Hazardous Waste.

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Section VIII: Special Protection Informaton


VX Concentration         Respiratory Protective Equipment

Less than 0.00001 mg/m3  M9, M17, or M40 series mask shall be available for escape
                         as necessary

0.00001 mg/m3 to 0.02 mg/m3   M9, or M40 series mask with Level A or Level B protective
                              ensemble (see AMCR 385-131 for determination of
                              appropirate level).

                         Demilitarization Protective Emsemble (DPE), or
                         Toxicological Agent Protective Ensemble Self-Contained
                         (TAPES), used with prior approval from AMC Field Safety

Greater than 0.02 mg/m3 or    DPE or TAPES used with prior approval from AMC Field 
unknown                  Field Safety Activity

                         NOTE:  When DPE or TAPES is not available the M9 or
                         M40 series mask with Level A protective ensemble can be
                         used.  However, use time shall be restricted to the extent
                         operationally feasible, and may not exceed one hour.

                         As an additional precaution, the cuffs of the sleeves and the
                         legs of the M3 suit shall be taped to the gloves and boots
                         respectively to reduce aspiration.

VENTILATION: Local Exhaust: Must be filtered or scrubbed to limit exit <.00001 mg/m3.

Special: Chemical laboratory hoods shall have an average inward face velocity of 100 linear feet per minute (lfpm) + 10 percent with the velocity at any point not deviating from the average face velocity by more than 20 percent. Laboratory hoods shall be located such that cross-drafts do not exceed 20 percent of the inward face velocity. A visual performance test utilizing smoke- producing devices shall be performed in assessing the ability of the hood to contain agent VX.

Emergency back-up power necessary. Hoods should be tested semi-annually or after modification or maintenance operations. Operations should be performed 20 cm inside hood face.

Other: Recirculation of exhaust air from agent areas is prohibited. No connection between agent areas and other areas through ventilation system is permitted.

PROTECTIVE GLOVES: Butyl Glove M3 and M4; Northon, Chemical Protective Glove Set

EYE PROTECTION: Chemical Goggles. For splash hazards use goggles and faceshield.


Full protective clothing will consist of M9 mask and hood, m3 butyl rubber suit (M3), M2A1 butyl boots, M3 and M4 gloves, unimpregnated underwear, or demilitarization protective ensemble (DPE). For laboratory operations, wear lab coats and have a protective mask readily available.

In addition, daily clean smock, foot covers, and head covers will be required when handling contaminated lab animals.

MONITORING: Available monitoring equipment for agent HD is the M8/M9 Detector paper, ACADA), detector ticket, M256/M256A1 kits, bubbler. Depot Area Air Monitoring System (DAMMS), Automated Continuous Air Monitoring System (ACMS), Real-Time Monitor (RTM), Demilitarization Chemical Agent Concentrator (DCAC), M8/M43, M8A1/M43A1, CAM-M1, Hydrogen Flame Photometric Emission Detector (HYFED), and the Minature Chemical Agent Monitor (MINICAM).

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Section IX: Special Precautions

PRECAUTIONS TO BE TAKEN IN HANDLING AND STORING: In handling, the buddy system will be incorporated. No smoking, eating or drinking in areas containing agent is permitted. Containers should be periodically inspected for leaks (either visually or by a detector kit). Stringent control over all personnel practices must be exercised. Decontamination equipment shall be conveniently located. Exits must be designed to permit rapid evacuation. Chemical showers, eyewash stations, and personal cleanliness facilities shall be provided. Wash hands before meals and each worker will shower thoroughly with special attention given to hair, face, neck, and hands, using plenty of soap before leaving at the end of the workday.

OTHER PRECAUTIONS: Agent must be double-contained in liquid and vapor-tight containers when in storage or when outside of the ventilation hood.

For additional information, see AMC-R 385-131, "Safety Regulations for Chemical Agents H, HD, HT, GB, and VX" and USAEHA Technical Guide No. 169, "Occupational Health Guidelines for the Evaluation and Control of Occupational Exposure to Nerve Agents GA, GB, GD, and VX."

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Section X: Transportation Data

PROPER SHIPPING NAME: Poisonous liquid, n.o.s.


DOT LABEL: Poison gas

DOT MARKING: Poisonous liquid, n.o.s. (O-ethyl S-(2-diisopropylaminoothyl) methyl phosphonothioate) NA 1955




Motor vehicles will be placarded regardless of quantity. Driver shall be given full and complete information regarding shipment and conditions in case of emergency. AR 50-6 deals specifically with the shipment of chemical agents. Shipments of agent will be escorted in accordance with AR 740-32.

While the Chemical Research Development and Engineering Center, Department of the Army believes that the data contained herein are factual and the opinions expressed are those of qualified experts regarding the results of the tests conducted, the data are not to be taken as a warranty or representation for which the Department of the Army or Chemical Research Development Engineering Center assumes legal responsibility. They are offered solely for your consideration, investigation, and verification. Any use of these data and information must be determined by the user to be in accordance with applicable Federal, State, and local laws and regulations.

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Addendum A: Physiological Effects


          Site of Action      Signs and Symptoms
                              Following  Local Exposure

          Pupils              Miosis, marked, usually maximal (pinpoint),
                              sometimes unequal.

          Ciliary body        Frontal headache, eye pain on focusing, slight
                              dimness of vision, occasional nausea and vomiting.

          Conjunctivae        Hyperemia

          Nasal mucous membranes             Rhinorrhea, hyperemia

          Bronchial tree      Tightness in chest, sometimes with prolonged
                              wheezing expiration suggestive of broncho-
                              constriction or increased secretion, cough..

                              Following Systemic Absorption

          Bronchial tree      Tightness in chest, with prolonged wheezing,
                              expiration suggestive of broncho-constricion or
                              increased secretion, dyspnea, slight pain in chest,
                              increased bronchial secretion, cough, pulmonary
                              edema, cyanosis.

          Gastrointestinal    Anorexia, nausea, vomiting, abdominal cramps,
                              epigastric and substernal tightness (cardiospasm)
                              with "heartburn" and eructation, diarrhea, tenesmus,
                              involuntary defecation.

          Sweat glands        Increased sweating

          Salivary glands     Increased salivation

          Lacrimal glands     Increased lacrimation

          Heart               Slight bradycardia

          Pupils              Slight miosis, occasionally unequal, later maximal
                              miosis (pinpoint).

          Ciliary body        Blurring of vision

          Bladder             Frequent, involuntary micturition


          Striated muscle     Easy fatigue, mild weakness, muscular twitching,
                              fasciculations, cramps, generalized weakness,
                              including muscles of respiration, with dyspnea and

          Sympathetic ganglia Pallor, occasional elevation of blood pressure.

          Central Nervous system             Giddiness, tension, anxiety, jitteriness, restlessness,
                                             emotional lability, excessive dreaming, insomnia,
                                             nightmares, headaches, tremor, withdrawal and
                                             depression, bursts of slow waves of elevated
                                             voltage in EEG, especially on over-ventilation,
                                             drowsiness, difficult concentration, slowness on
                                             recall, confusion, slurred speech, ataxia,
                                             generalized weakness, coma, with absence of
                                             reflexes, Cheyne-Stokes respirations, convulsions,
                                             depression of respiratory and circulatory centers,
                                             with dyspnea, cyanosis, and fall in blood pressure.


Acute Exposure

Chronic Exposure

Et50           Degree of           ICt50          Exposure Time

min                                mg min/m3      min

1.5            Moderate            27             0.5
3.0            Incap.              27             2.0
6.0                                40             10.0

1.0            Severe              37             0.5
3.8            Incap.              37             2.0
7.8                                56             10.0

2.0            Very                47             0.5
4.5            Severe              47             2.0
9.5            Incap.              72             10.0

6.5            Death               70             5.0
9.0                                70             2.0
13.5                               103            10.0

Exposure to high concentrations of nerve agent may bring on incoordination, mental confusion
and collapse so rapidly that the casualty cannot perform self-aid.  If this happens, the man
nearest to him will give first aid.

Onset Time of Symptoms
                                             When Effects
Types of  Route of  Description              Appear After
Effects   Absorption                         of Effects          Exposure

Vapor     Lungs     Rhinorrhea, nasal Hyperemia                  One to several minutes
Local               tightness in chest, wheezing

Vapor     Eyes      Miosis, conjectival hyperemia                One to several minutes
Local               eye pain, frontal headache

Vapor     Lungs or  Muscarine-like, nicotine-like                Less than 1 min. to a few
Systemic  eyes      and central nervous system                   after moderate or marked
                    effects.  (See 2a above) exposure: about 30 min. after
                                             mild exposure

Liquid    Eyes      Same as vapor effects    Instantly

Liquid    Ingestion Gastrointestinal.  (See 2a above).           About 30 min. after ingestion

Liquid    Skin      Local sweating and muscular                  3 min to 2 hours
Local               twitching

Liquid    Lungs     See 2a above             Several minutes

Liquid    Eyes      Same as for vapor        Several minutes

Liquid    Skin      Generalized sweating     15 minutes to 2 hours

Liquid    Ingestion Gastrointestinal (see 2a above)              15 minutes to 2 hours

Onset Time of Symptoms. (cont'd)
Duration of Effects After
Types of    Route of          Mild           Severe
Effects     Absorption        Exposure       Exposure
Vapor       Lungs             A few hours    1 to 2 days

Vapor       Eyes              Miosis -       3 to 14 days
Local                         24 hours       2 to 5 days

Vapor       Lungs or eyes     Several hours  8 days

Liquid      Eyes              Similar to effects
Local                         of vapor

Liquid      Ingestion         3 days         5 days

Liquid      Skin              3 days         5 days

Liquid      Lungs                            1 to 5 days

Liquid      Eyes                             2 to 4 days

Liquid      Skin                             2 to 5 days

Liquid      Ingestion                        3 to 5 days


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Addendum B: First Aid Procedures

  1. Exposed personnel will be removed immediately to an uncontaminated atmosphere. Personnel handling casualty cases will give consideration to their own safety and will take precautions and employ the prerequisite protective equipment to avoid becoming exposed themselves.

    CAUTION: Due to the rapid effects of nerve agents, it is extremely important that decontamination of personnel not be delayed by attempting to blot off excessive agent prior to decontamination with sodium hypochlorite.

  2. The causalty will then be decontaminated by immediately removing any contaminated clothing and washing the contaminated areas with copious amounts of soap and water, 5% sodium hypochlorite solution, or liquid household bleach (nominal 5% solution sodium hypochlorite) and flushing with clean water. Mask will be left on the victim until decontamination has been completed unless it has been determined that areas of the face were contaminated and the mask must be removed to facilitate decontamination. After decontamination, the contaminated clothing will be removed and skin contamination washed away. If possible, decontamination will be completed before the casualty is taken to the aid station of medical facility.

    CAUTION: Care must be taken when decontaminating facial areas to avoid getting the hypochlorite into the eye or mouth. Only clean water shall be used when flushing the eyes or mouth. Skin surfaces decontaminated with bleach should be thoroughly flushed with water to prevent skin irritation from the bleach.

  3. If there is no apparent breathing, artifical resuscitation will be started immediately (mouth-to-mouth, or with mechanical resuscitator). The situation will dictate method of choice, e.g., contaminated face. Do not use mouth-to-mouth resuscitation when facial contamination exists. When appropriate and trained personnel are available, cardiopulmonary resuscitation (CPR) may be necessary.

  4. An individual who has received a known agent exposure or who exhibits definite signs or symptoms of agent exposure shall be injected immediately with the Nerve Agent Antidote Kit, MARK I.

    1. Some of the early symptoms of a vapor exposure may be rhinorrhea (runny nose) and/or tightness in the chest with shortness of breath (bronchial construction).

    2. Some of the early symptoms of a percutaneous exposure may be local muscular twitching or sweating at the area of exposure followed by nausea or vomiting.

    3. Although myosis (pin-pointing of the pupils) may be an early sign of agent exposure, a Mark I Kit shall not be administered when myosis is the only sign present. Instead, the individual shall be taken immediately to the medical facility for observation.

    4. Injections using the MARK I kit injectors (or atropine only if directed by the local physician) may be repeated at 5 to 20 minute intervals if signs and symptoms are progressing until three series of injections have been administered. No more injections will be given unless directed by medical personnel. In addition, a record will maintained of all injections given.

    5. Administer, in rapid succession, all three MARK I kit injectors (or atropine if directed by the local physician) in the case of SEVERE signs of agent exposure.

      CAUTION: The nerve Agent Antidote Kit, MARK I does not act as a prophylactic and shall not be administered until an agent exposure has been ascertained.

  5. If indicated, CPR should be started immediately. Mouth-to-mouth resuscitation should be used when approved mask-bag or oxygen delivery systems are not available. Do not use mouth-to-mouth resuscitation when facial contamination exists.
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