Ricin - Use As A Chemical/biological Warfare Agent

Use As A Chemical/biological Warfare Agent

The United States investigated ricin for its military potential during World War I. At that time it was being considered for use either as a toxic dust or as a coating for bullets and shrapnel. The dust cloud concept could not be adequately developed, and the coated bullet/shrapnel concept would violate the Hague Convention of 1899 (adopted in U.S. law at 32 Stat. 1903), specifically Annex § 2, Ch.1, Article 23, stating "...it is especially prohibited...o employ poison or poisoned arms". World War I ended before the U.S. weaponized ricin.

During WWII the US and Canada undertook studying ricin in cluster bombs. Though there were plans for mass production and several field trials with different bomblet concepts, the end conclusion was that it was no more economical than using phosgene. This conclusion was based on comparison of the final weapons rather than ricin's toxicity (LCt₅₀ ~40 mg·min/m3). Ricin was given the military symbol W or later WA. Interest in it continued for a short period after WWII, but soon subsided when the U.S. Army Chemical Corps began a program to weaponize sarin.

The Soviet Union also possessed weaponized ricin. There were speculations that the KGB used it outside of the Soviet bloc; however, this was never proven. In 1978, the Bulgarian dissident Georgi Markov was assassinated by Bulgarian secret police who surreptitiously 'shot' him on a London street with a modified umbrella using compressed gas to fire a tiny pellet contaminated with ricin into his leg. He died in a hospital a few days later; his body was passed to a special poison branch of the British Ministry of Defence (MOD) that discovered the pellet during an autopsy. The prime suspects were the Bulgarian secret police: Georgi Markov had defected from Bulgaria some years previously and had subsequently written books and made radio broadcasts which were highly critical of the Bulgarian communist regime. However, it was believed at the time that Bulgaria would not have been able to produce the pellet, and it was also believed that the KGB had supplied it. The KGB denied any involvement although high-profile KGB defectors Oleg Kalugin and Oleg Gordievsky have since confirmed the KGB's involvement. Earlier, Soviet dissident Aleksandr Solzhenitsyn also suffered (but survived) ricin-like symptoms after a 1971 encounter with KGB agents.

Despite ricin's extreme toxicity and utility as an agent of chemical/biological warfare, it is extremely difficult to limit the production of the toxin. The castor bean plant from which ricin is derived is a common ornamental and can be grown at home without any special care, and the major reason ricin is a public health threat is that it is easy to obtain.

Under both the 1972 Biological Weapons Convention and the 1997 Chemical Weapons Convention, ricin is listed as a schedule 1 controlled substance. Despite this, more than 1 million tonnes of castor beans are processed each year, and approximately 5% of the total is rendered into a waste containing negligible concentrations of undenatured ricin toxin.

Ricin is several orders of magnitude less toxic than botulinum or tetanus toxin, but the latter are harder to come by. Compared to botulinum or anthrax as biological weapons or chemical weapons, the quantity of ricin required to achieve LD₅₀ over a large geographic area is significantly more than an agent such as anthrax (tons of ricin vs. only kilogram quantities of anthrax). Ricin is easy to produce, but is not as practical nor likely to cause as many casualties as other agents. Ricin is inactivated (the protein changes structure and becomes less dangerous) much more readily than anthrax spores, which may remain lethal for decades. Jan van Aken, a Dutch expert on biological weapons, explained in a report for The Sunshine Project that Al Qaeda's experiments with ricin suggest their inability to produce botulinum or anthrax.

Ian Davison, a British white supremacist and neo-Nazi, was arrested in 2009 for planning terrorist attacks involving ricin.

In 2011 the US government discovered information that terrorist groups were attempting to obtain large amounts of castor beans for weaponized ricin use.

On November 1, 2011 the FBI arrested 4 North Georgia men and charged them in plots to purchase explosives, a silencer and to manufacture the biological toxin ricin from castor beans.