Feared Chemical Agents
An effective chemical attack would use chemicals that are extremely toxic to people in small quantities. The most commonly feared agents include:

  • Sarin - Sarin is a nerve agent. This means that, once inside your body, it affects the signaling mechanism that nerve cells use to communicate with one another.

    Sarin is a cholinesterase inhibitor -- it gums up the cholinesterase enzyme, which your nerve cells use to clear themselves of acetylcholine. When a nerve cell needs to send a message to another nerve cell (for example, to cause a muscle to contract), it sends the message with the acetylcholine. Without cholinesterase to clear the acetylcholine, muscles start to contract uncontrollably, which eventually causes death by suffocation (since the diaphragm is a muscle).

    Sarin is probably the most feared chemical agent because it has actually been used by terrorists to kill people. In 1995, the group Aum Shinrikyo released sarin gas in the Tokyo subway, wounding thousands and killing 12 people. It is not particularly difficult to manufacture, and about 1 milligram in the lungs will kill a person.

  • VX - VX is very similar to Sarin. It works in the same way, but is more toxic. One milligram on the skin will kill a person. See this page for more information.

  • Mustard Gas - Mustard gas has been around since World War I. It blisters the skin and destroys lung tissue. About 10 milligrams in the lungs will kill a person.

  • Lewisite - Lewisite, like mustard gas, is a blistering agent, and has also been around since World War I.


One of the problems with these chemical agents is that there is no easy way to protect yourself. On the battlefield, soldiers wear gas masks and complete skin covering when chemical or biological attack is deemed possible. If a city were to experience a large-scale VX attack, people would have to be wearing a waterproof and airtight suit and a gas mask at the time of the attack in order to be protected.