What is VX - the nerve agent that was allegedly used to kill Kim Jong-nam?

A preliminary report investigating the death of Kim Jong-nam has revealed the chemical used in the assassination: VX, a nerve agent classified as a chemical weapon and a weapon of mass destruction by the United Nations.

Samples retrieved from the estranged half-brother of North Korean leader Kim Jong Un were analysed by the Centre for Chemical Weapons Analysis of the Chemistry Department.

Kim Jong-nam was allegedly smeared with the nerve agent by two female suspects at the Kuala Lumpur International Airport 2 (KLIA2) last Monday (Feb 13), moments before he was supposed to board a flight to Macau.

Here are 10 things to know about VX:

1. Discovered in Britain

The VX nerve agent was first made by the British in the 50s for a V-series of chemical weapons based on pesticides. The V-series of nerve agents does not wash away easily and evaporates slowly, hence the title: persistent agents. The best know V-agent is VX.

2. Invisible

Highly viscous, odourless and tasteless, VX has a brownish-tinge. Its vapour form is the deadliest, while it can be used to contaminate water supply sources, or simply as a poison in food.

3. 3 minutes is all it takes

A single drop of VX on the skin can kill a person within three minutes. Signs of VX poisoning include confusion, drowsiness, paralysis and respiratory failure.

4. Area denial weapon

Because of its persistent qualities, VX is considered an area denial weapon, meaning that it can restrict and slow down enemy troops by blanketing an area with the chemical - usually through warheads.

5. Poor man's atomic bomb

Chemical and biological weapons are often described as the 'poor man's atomic bomb'. Cheaper and less sophisticated than nuclear weapons, a bottle of VX can easily kill 50,000 people, according to Dr Graham Pearson, the former head of Britain's chemical and biological defence establishment.

6. Unaccounted stockpiles

In 1995, officials in then-Saddam's Iraq admitted that its scientists were producing VX from Sept 1987 to Sept 1988. Materials enough to make at leat 250 tonnes of VX were unaccounted in the following years.

7. Other VX attacks

Kim Jong-nam is not the first known victim to die from VX. Between Dec 12, 1994, a doomsday cult from Japan used VX to kill a 28-year-old man by sprinkling VX on the victim's neck. The cult - Aum Shinrikyo - is also the same group behind the 1995 Tokyo subway sarin attack that killed 12 people, injured 50 and caused temporary vision problems for nearly 5,000 others. Then, members of the Aum Shinrikyo cult leaked another nerve agent, sarin, contained in plastic bags in train carriages. VX is said to be about 10 times more lethal than sarin.

8. Outlawed

The Chemical Weapons Convention is the first international treaty to outlaw an entire class of weapons, including mustard gas and nerve agents like sarin and VX. The convention has been ratified by 189 states.

9. Other stockpiles

US and Russia are the only countries that have declared their VX stockpiles, but there are many other countries who are believed to have it too.

10. Detecting it

Singapore's national defence research agency - DSO National Laboratories (DSO) - has been developing a portable kit to detect nerve agents such as VX and sarin since 1999. In 2002, scientists from DSO and Nanyang Technological University (NTU) developed cheap test kits called Scentmate to test for nerve gases. Scentmate can screen blood samples from 96 people in 30 minutes, compared to 16 hours to screen as many samples in a laboratory. There are antidotes to counter VX, but given the lethality of the nerve agent, it must be administered immediately.

Sources: Reuters, The Guardian, CNN, The Straits Times

grongloh@sph.com.sg