9 Most Horrendous Chemical Weapons

7. Mustard Gas

Mustard gas will probably only kill around 5% of the people exposed to it, but just because it is not as toxic as some other chemical weapons, doesn't mean it's any less unpleasant.

It is a blistering agent that will cause extreme burns on contact with the skin and mucus membranes such as eyes, throat and lungs. The resultant blistering and scarring can be not only painful, but deadly, particularly if located in the lungs. Although many victims of a gas attack will survive and eventually recover, it can cause permanent disfigurement, blindness and scarring. It also increases the chances that victims with develop deadly respiratory diseases and even cancer.

Mustard gas, or sulfur mustard as it is also known, was used widely in both world wars and several other conflicts since.

Amazingly, this horribly destructive weapon also gave rise to the development of the very first chemotherapy drug, known as HN2 or Mustine which is still used today.