IPOH, MALAYSIA–This week, Malaysian authorities identified VX nerve agent as the toxic substance used in the assassination of Kim Jong Nam, the estranged half-brother of North Korean dictator Kim Jong Un. The attack appears to have been a complicated one—one that required two assailants to administer two halves of a chemical weapon that only became lethal when combined.
Malaysian police said they found evidence of the chemical weapon on Jong Nam’s eyes and face. Some chemical weapons experts question whether VX was used, not only because of the availability of the substance but because of its potency.
Speaking to New Scientist, Richard Guthrie, who worked for the Stockholm International Peace Institute, says that he has “more questions than answers at this point.” VX is the most toxic substance in existence, and requires only 10 milligrams—less than a drop—to be lethal. Merely touching the oily liquid is enough to kill you, unless immediately treated.
Video footage of the murder shows a female assailant dressed in a long-sleeved white shirt putting her hand around Jong Nam’s face for a few seconds before walking off. Jong Nam then walks around steadily, finding help from airport staff at a medical station to complain about irritation to his eyes and face.
The substance used to kill Jong Nam took some time to take effect, and his assailants—two women who claim they were partaking in a viral video prank—did not die, nor did anyone who treated the victim. The woman in the white shirt can be seen wearing a dark-colored glove in the video during the attack, and subsequent footage of her leaving the airport shows that she no longer had the glove on.
The two women are reported to have gone into a washroom to wash their hands, where one of them vomited. In addition to their apparent lack of serious protection, only one assailant exhibited slight symptoms of poisoning (vomiting), while the other was otherwise unaffected.
Chemical weapons expert Jean-Pascal Zanders told The New Scientist: “Any splash of a tiny droplet anywhere on [the unaffected assailant’s] body would have resulted in some symptoms. She was jailed, but nothing like that was reported.”
However, VX can be administered as a binary chemical weapon—meaning one assailant could have handled Agent QL (O-[2-diisopropylaminoethyl] O′-ethyl methylphosphonite) while the other handled Agent NE (elemental sulfur), or possibly Agent NM (liquid dimethyl polysulfide). All agents are individually toxic, which would explain the vomiting, but not virulently lethal unless combined.
John Robertson, who runs The Poison Garden, a website on poisons and chemical weapons, speculated on Scientific American that each woman may have been carrying separate substances, which would have reacted on the victim’s face to produce the nerve agent. Users on Reddit are speculating about how this would work, and about how neither woman may have been aware of the substance’s lethality.
There are suggestions that both assailants could have taken atropine shots, which inhibit the effects of the nerve agent. However, a single shot would not have been enough to treat its effects, which require atropine to be administered over a period of hours. Given that neither suspect was immediately arrested, there is a possibility that they took atropine shots before being apprehended by police.
Curiously, Malaysian police did not find it necessary to immediately shut down the airport concourse to decontaminate the area as no one else was affected. It is only being cleaned now.
There’s a reason for why VX, if it was used, may not have posed lethality to anyone besides Jong Nam—the active agents may not have been fresh. All individual portions of VX can degrade rapidly in storage, and had old batches been used, it wouldn’t have the same potency as something new.
North Korea is thought to produce and house large quantities of chemical weapons, and to have aided Syria in building their stockpile. It is one of only four countries that refused to sign treaties banning chemical weapons.
Ian Miles Cheong is a journalist and outspoken media critic. You can reach him through social media at @stillgray on Twitter and on Facebook.