2) MUSTARD GAS:
One of the best-known chemical weapons, mustard gas is a blister agent that attacks the eyes and skin, causing severe blisters. If inhaled, it can also damage the lungs and other organs.
The gas does not cause immediate symptoms, which means those exposed to it can unknowingly take high dosages. While not usually lethal, exposure to mustard gas is generally debilitating.
Mustard gas was first used by the German army in World War I against British forces. Saddam Hussein was accused of using the gas in Iraq's war with Iran, as well as in his 1987-1988 crackdown on the country's Kurdish minority.
The most notorious case was on the village of Halabja, which killed some 5,000 people in the deadliest chemical weapons attack ever against civilians.
