Ricin is expected to be present anytime the castor seed pods are being handled or processed. Heating of the beans during the oil process denatures and removes the ricin toxin in the oil. The remaining mash/cake from processing the seeds contains ricin and must be handled appropriately. It would take a deliberate act to make ricin and use it to poison people. Unintentional exposure to ricin is highly unlikely, except through the ingestion of castor beans.
- Ricin. Centers for Disease Control and Prevention (CDC).
- Ricin: Biotoxin. National Institute of Occupational Safety and Health (NIOSH).
- PubChem for Ricin. The National Library of Medicine.
- Plants Poisonous to Livestock: Ricin Toxin From Castor Bean Plant, Ricinus communis. Cornell University, Department of Animal Science.
- Medical Management of Biological Casualties Handbook Seventh Edition. U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), (September 2011). Contains specific information on a number of potential bioterrorist agents.
- Medical Aspects of Chemical and Biological Warfare Chapter 32 Ricin. US Army Medical Center for Excellence: The Borden Institute: Medical Aspects of Chemical and Biological Warfare Chapter 32 Ricin.
Ricin as a Weapon
Ricin may have significance as a biological weapon since it is easy to produce and is stable. In addition to being found on the U.S. Capital, the ricin toxin has also been used or suspected during the following instances:
- Ricin was considered for weaponization by the United States during its offensive Biological Warfare Program. Such a weapon was tested but apparently never used in battle.
- Ricin was used in the highly publicized assassination of Bulgarian defector Georgi Markov in 1978. An attacker used an umbrella rigged with a special tip to inject a ricin pellet under Markov's skin.
- Some reports have indicated that ricin may have been used in the Iran-Iraq war during the 1980s, and that quantities of ricin were found in Al Qaeda caves in Afghanistan.
- Two tax protestors were convicted in 1995 under the Anti-Terrorism Act for possessing ricin as a biological weapon.
- A retired electrician was arrested in 1995 under the Anti-Terrorism Act for possessing castor beans. Two years before, a large quantity of ricin toxin, weapons, ammunition, and gold were found in his car by Canadian customs officials as he crossed the border from Alaska to Canada.
- In October, 2003, an envelope with a threatening note and a sealed container with ricin was discovered at a mail processing and distribution facility in Greenville, South Carolina. No ricin-associated illnesses were identified as a result of the incident.
- In 2013, a TV actress was arrested and charged Friday in connection with ricin-laced letters sent to President Obama and New York City Mayor Michael Bloomberg.
- Pennsylvania man admitted sending ricin-laced scratch-n-sniff card to ex's new boyfriend in November 2014.
- In February 2017, the FBI investigated a Georgia man with ties to the white supremacist Creativity Movement after he sought medical attention for exposure to the deadly poison ricin.
- An envelope addressed to President Donald Trump contained a substance suspected to be ricin and appeared to be connected to similar envelopes sent to the Pentagon. Two pieces of mail delivered to the Pentagon mail facility initially tested positive for ricin, in October 2018.