Ricin: Background Information for Clinicians
- Ricin is a potent biological toxin (toxic protein) derived from part of the “waste” mash when beans from the castor plant (Ricinus communis) are processed during manufacture of castor oil.
- Ricin is a stable substance, affected very little by extreme conditions, such as very hot or very cold temperatures.
- Ricin can be in the form of a powder, a mist, a pellet, or it can be dissolved in water or weak acid.
- It is water-soluble, odorless, tasteless, and stable under ambient conditions.
- If the route of exposure is injection or inhalation, as little as 500 µg of ricin could be enough to kill an adult. A greater amount would be needed to cause death if ricin were ingested.
- The extent of manifestations of ricin poisoning in humans depends on the amount of ricin to which a person was exposed, route of exposure, and extent of organ involvement.
- Significant exposure to ricin would result in a relatively rapid, progressive worsening of symptoms over approximately 4 to 36 hours.
- Death may occur within 36-72 hours of exposure.
- It takes a deliberate act to manufacture ricin to poison people.
- There have been several instances of ricin procurement for use as a terrorist or criminal weapon.
- As a chemical weapon, ricin may be dispersed as a mist or powder, used to poison water or to contaminate food, or injected as a liquid into a person's body.
- No antidote exists for ricin.
- The most important factor is to avoid exposure.
- If exposure cannot be avoided, then the most important factors are to get ricin off or out of the body as quickly as possible, and to provide supportive medical care.
- Ricin poisoning represents a potential public health emergency and should be reported to public health agencies and the regional poison control center.
For additional information:
- Page last reviewed May 8, 2013
- Page last updated May 8, 2013
- Content source: National Center for Environmental Health (NCEH)/Agency for Toxic Substances and Disease Registry (ATSDR)