The instruments of governments, assassins and terrorists for decades

Nerve agents have been used for assassination and terrorism attempts and in warfare for decades.

They disrupt electrical signals in the central nervous system and have a rapid and dramatic effect, even in tiny doses. Those exposed to the toxins find it hard to breathe and will vomit, convulse and lose control of bodily functions before dying through asphyxiation.

Nerve agents include VX, Sarin, Tabun, Soman and GF. VX is the most toxic and is classified by the United Nations as a weapon of mass destruction. It comes in liquid, gas or cream form and a victim subjected to as little as 10mg can die within 15 minutes. Anyone coming into contact with a victim can also fall ill.

It was developed in the UK in the Fifties by scientists who were stunned by its toxicity. VX was used to murder Kim Jong-nam at Kuala Lumpur airport when two women smeared Vxsoaked cloths in his face. He was able to alert officials but was dead within 20 minutes.

The Aum Shinrikyo cult in Japan used VX to kill dissenters during the Nineties before releasing Sarin in Toyko’s underground railway system, killing 12 and leaving 600 in need of treatment.

Sarin has more recently been used by Syria in the country’s civil war, prompting retaliatory missile strikes by the US.