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Indiana State Department of Health

Public Health Preparedness Home > Chemical Agents > VX Facts About VX

Please click here for information about VX and the Newport Chemical Agent Disposal Facility

What VX is

  • VX is a human-made chemical warfare agent classified as a nerve agent. Nerve agents are the most toxic and rapidly acting of the known chemical warfare agents. They are similar to insecticides called organophosphate insecticides in terms of how they work and what kinds of harmful effects they cause. However, nerve agents are much more potent than insecticides.
  • VX was originally developed in the United Kingdom in 1952 by scientists who were searching for a replacement for the insecticide DDT.
  • VX is odorless and tasteless.
  • VX is an oily liquid that is amber in color and very slow to evaporate. It evaporates about as slowly as motor oil.

Where VX is found and how it is used

  • VX is not found naturally in the environment.
  • It is possible that VX or other nerve agents were used in chemical warfare during the Iran-Iraq War in the 1980s.

How people can be exposed to VX

  • Following release of VX into the air, people can be exposed through skin contact, eye contact, or inhalation (breathing in the VX mist).
  • Following release of VX into water, people can be exposed by drinking contaminated water or getting contaminated water on their skin.
  • Following contamination of food with VX, people can be exposed by eating the contaminated food.
  • VX is primarily a liquid exposure hazard, but if it is heated to very high temperatures, it can turn into small amounts of vapor (gas).
  • VX breaks down slowly in the body, meaning that repeated exposures to VX and/or other nerve agents can have a cumulative effect (build up in the body).

How VX works

  • The extent of poisoning caused by VX depends on the amount of VX a person was exposed to, how the person was exposed, and the length of time of the exposure.
  • Symptoms will appear within a few seconds after exposure to the vapor form of VX, and within a few minutes to up to 18 hours after exposure to the liquid form.
  • VX is the most potent of all nerve agents. Compared with the nerve agent sarin (also known as GB), VX is considered to be much more toxic by entry through the skin and somewhat more toxic by inhalation.
  • A tiny droplet of liquid VX—about the size of the head of a pin—would be enough to kill half the people who got it on their skin.
  • All the nerve agents cause their toxic effects by preventing the proper operation of the chemical that acts as the body’s “off switch” for glands and muscles. Without an “off switch,” the glands and muscles are constantly being stimulated. They may tire and no longer be able to sustain breathing function.
  • VX vapor is heavier than air, so it would be more likely to settle in low-lying areas.
  • Water could be used to deliver VX, though VX does not mix with water as easily as other nerve agents do.
  • VX is the least volatile of the nerve agents, which means that it is the slowest to evaporate from a liquid into a vapor. Therefore, VX is very persistent in the environment. Under average weather conditions, VX can last for days on objects that it has come in contact with. Under very cold conditions, VX can last for months.
  • Because it evaporates so slowly, VX can be a long-term threat as well as a short-term threat. Surfaces contaminated with VX should therefore be considered a long-term hazard.

Immediate signs and symptoms of VX exposure

  • People may not know they were exposed to VX because it has no odor.
  • People exposed to a low or moderate dose of VX by inhalation, ingestion (swallowing), or skin absorption may experience some or all of the following symptoms within seconds to hours of exposure:
    • Runny nose
    • Watery eyes
    • Small, pinpoint pupils
    • Eye pain
    • Blurred vision
    • Drooling and excessive sweating
    • Cough
    • Chest tightness
    • Rapid breathing
    • Diarrhea
    • Increased urination
    • Confusion
    • Drowsiness
    • Weakness
    • Headache
    • Nausea, vomiting, and/or abdominal pain
    • Slow or fast heart rate
    • Abnormally low or high blood pressure
  • Even a tiny drop of nerve agent on the skin can cause sweating and muscle twitching where the agent touched the skin.
  • Exposure to a large dose of VX by any route may result in these additional health effects:
    • Loss of consciousness
    • Convulsions
    • Paralysis
    • Respiratory failure possibly leading to death

What the long-term health effects are

Mild or moderately exposed people usually recover completely. Severely exposed people are not likely to survive.

How people can protect themselves and what they should do if they are exposed to VX

  • Recovery from VX exposure is possible with treatment, but the antidotes available must be used quickly to be effective. Therefore, the best thing to do is avoid exposure. If exposure cannot be avoided, rapidly decontaminate and get medical care as quickly as possible.
  • Leave the area where the VX was released and get to fresh air. Quickly moving to an area where fresh air is available is highly effective in reducing the possibility of death from exposure to VX vapor.
    • If the VX release was outdoors, move away from the area where the VX was released. Go to the highest ground possible, because VX is heavier than air and will sink to low-lying areas.
    • If the VX release was indoors, get out of the building.
  • Remove any clothing that has liquid VX on it, and if possible, seal the clothing in a plastic bag. Then seal the first plastic bag in a second plastic bag. Removing and sealing the clothing in this way will protect you and others from any chemicals that might be on your clothes.
  • If helping other people remove their clothing, try to avoid touching any contaminated areas, and remove the clothing as quickly as possible.
  • Rinse the eyes with plain water for 10 to 15 minutes if they are burning or vision is blurred.
  • As quickly as possible, wash any liquid VX from the skin with large amounts of soap and water. Washing with soap and water will protect people from any chemicals on their bodies.
  • If VX has been ingested (swallowed), do not induce vomiting or give fluids to drink. Seek medical attention right away.
  • Stay calm. Dial 911 and explain what has happened.
  • Wait for emergency personnel to arrive.


How VX poisoning is treated

VX poisoning is treated with antidotes and supportive medical care. The most important thing is for victims to be rapidly decontaminated and get medical treatment as soon as possible.