1. Sarin has no colour or smell as a liquid but can be changed into a gas which spreads into the environment
2. If someone is exposed to a big dose of sarin they will die.
3. Symptoms of exposure to sarin include convulsions, paralysis, not breathing and dying.
4. This poison was the one used in the infamous Tokyo subway attack in 1995 which killed 12.
5. The most deadly attack with Sarin was in the Kurdish town of Halabja in which thousands of civillians died in an attack blamed on then Iraqi President Saddam Hussein.