A potent protein toxin made from the waste left over from processing castor beans.
The castor plant, which is called Ricinus communis, is found throughout the world.
Ricin is fairly easy to extract. Worldwide a million tons of castor beans are processed
annually in the production of castor oil. The waste mash from this process is 5% ricin
by weight. The toxin (ricin) can be in the form of a powder, mist, pellet, or it can be
dissolved in water or weak acid. Ricin is quite stable and is not affected much by
extreme conditions such as very hot or very cold temperatures. Ricin is extremely toxic
by several routes of exposure. When inhaled as a small particle aerosol, this toxin can
produce pathologic changes within 8 hours and severe respiratory symptoms followed
by acute hypoxic (low oxygen) respiratory failure within 36-72 hours. When ingested,
ricin causes severe gastrointestinal symptoms followed by vascular collapse and
death. Signs and symptoms of ricin inhalation include the acute onset of fever, chest
tightness, cough, dyspnea, nausea, and arthralgia (joint pain) occurs 4 to 8 hours after
inhalational exposure. Airway necrosis and pulmonary capillary leak resulting in
pulmonary edema are likely to occur within 18-24 hours, followed by severe respiratory
distress and death from hypoxemia in 36-72 hours. Diagnosis is by antigen detection
(ELISA) in blood serum and respiratory secretions. Acute and convalescent sera
provide confirmation. Treatment is supportive. There is no vaccine or prophylactic
antitoxin. Use of a protective mask is currently the best protection against inhalation.
Ricin is not volatile. Decontamination should be done with soap and water.
Hypochlorite solutions also can inactivate ricin. Ricin's significance as a potential
biological warfare toxin relates in part to its wide availability. Ricin is feared to have a
high terrorist potential due to its ready availability, relative ease of extraction, and
notoriety via the media. The CDC has classified Ricin toxin as a Category B