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Castor Beans
Castor Beans

RICIN (Toxic Substance)

Science Reference Section
Science, Technology, and Business Division
Library of Congress

Ricin is a naturally occurring substance in the castor bean plant. It is made from waste left over after processing the beans in the production of castor oil, which is used mainly in industry and medicines. Obtaining ricin is a simple process of extraction after the castor oil has been removed. Ricin is a highly toxic poison, but has limited value as a harmful biological agent.

Harmful biological agents are generally divided into either infectious agents or non-infectious agents. Infectious agents are:

  • pathogenic bacteria
  • viruses
  • funguses, such as anthrax or smallpox.
Ricinus communis
Non-infectious agents are called "toxins" and are produced from:
  • infectious agents
  • other living organisms and plants
Ricin is a toxin produced by the castor bean plant.

Compared to infectious biological agents such as smallpox, ricin’s usefulness as a weapon is limited . Not only is a large amount of ricin necessary to produce the desired effect, it does not convert easily to an aerosol form, and it does not grow and spread. It is not contagious.

Ricin Fact Sheet Emergency Preparedness & Response, Centers for Disease Control and Prevention
Also available in Spanish and with a downlodable PDF version for printing.

What is Ricin? Marshall Brain

Cornell Plant Database Ricinus communis (Castor bean)

Scientists Play Down Ricin's Lethal Threat Guy Gugliotta, Washington Post, Page A07, Feb 4, 2004.

Ricin Toxin from Castor Bean Plant Cornell University Poisonous Plants Information Database

As a harmful biological agent, ricin can be inhaled, injected or ingested. Though injection would only require a very small amount, a much larger dose would be needed if the ricin were inhaled or ingested. The appearance and type of symptoms depend on the type of exposure. Symptoms by inhalation may occur within 8 hours; symptoms by ingestion typically occur in less than 6 hours. Inhalation symptoms would typically include respiratory distress, fever, cough, tightness in the chest, and nausea. Death may be caused by low blood pressure and respiratory failure, and might occur 36 to 72 hours from the time of exposure.

Ricin Fact Sheet for Medical Providers

E-medicine CBRNE - Ricin

Medical NBC Online Information Server Office of the Surgeon General. Search engine, relevant Army Field Manuals in PDF format, full text of government documents. Archives include links to recent relevant news articles.

Chemical and Biological Warfare Tracer Bullet
Library of Congress Science Reference Services

Relevant books on the shelf in the Science Reference Collection include:

  • Croddy, Eric. Chemical and biological warfare: a comprehensive survey for the concerned citizen. New York, Springer-Verlag, c2002. 306 p. UG447.C755 2002.
  • Biological agents. In PDR guide to biological and chemical warfare response. Edited by David W. Sifton and Gwynned L. Kelly. Montvale, N.J., Thomson/Physicians' Desk Reference, c2002. p. 3-41. RA648 .P374 2002.

February 10, 2004

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