Frequently Asked Questions (FAQ) About Ricin

What Is Ricin?

  • Ricin is a poison that can be made from the waste left over from processing
    castor beans.


  • It can be in the form of a powder, a mist, or a pellet, or it can be
    dissolved in water or weak acid.
  • It is a stable substance. For example, it is not affected much by extreme
    conditions such as very hot or very cold temperatures.

Where Is Ricin Found, and How Is It Used?

  • Castor beans are
    processed throughout the world to make castor oil. Ricin is part of
    the waste “mash” produced when castor oil is made. Amateurs can make
    ricin from castor beans.
  • Ricin has some
    potential medical uses, such as bone marrow transplants and cancer treatment
    (to kill cancer cells).

How Can People Be Exposed to Ricin?

  • It would take a
    deliberate act to make ricin and use it to poison people. Accidental
    exposure to ricin is highly unlikely.
  • People can breathe
    in ricin mist or powder and be poisoned.
  • Ricin can also
    get into water or food and then be swallowed.
  • Pellets of ricin,
    or ricin dissolved in a liquid, can be injected into people’s bodies.
  • Depending on the
    route of exposure (such as injection), as little as 500 micrograms of
    ricin could be enough to kill an adult. A 500-microgram dose of ricin
    would be about the size of the head of a pin. A much greater amount
    would be needed to kill people if the ricin were inhaled (breathed in)
    or swallowed.
  • Ricin poisoning
    is not contagious. It cannot be spread from person to person through
    casual contact.


  • In 1978, Georgi
    Markov, a Bulgarian writer and journalist who was living in London,
    died after he was attacked by a man with an umbrella. The umbrella had
    been rigged to inject a poison 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.

How Does Ricin Work?


  • Ricin works by
    getting inside the cells of a person’s body and preventing the cells
    from making the proteins they need. Without the proteins, cells die,
    and eventually the whole body can shut down and die.
  • Specific effects
    of ricin poisoning depend on whether ricin was inhaled, swallowed, or

What Are the Signs and Symptoms of Ricin Exposure?

  • Inhalation:
    Within a few hours of inhaling significant amounts of ricin, the likely
    symptoms would be coughing, tightness in the chest, difficulty breathing,
    nausea, and aching muscles. Within the next few hours, the body’s airways
    (such as lungs) would become severely inflamed (swollen and hot), excess
    fluid would build up in the lungs, breathing would become even more
    difficult, and the skin might turn blue. Excess fluid in the lungs would
    be diagnosed by x-ray or by listening to the chest with a stethoscope.


  • Ingestion:
    If someone swallows a significant amount of ricin, he or she would have
    internal bleeding of the stomach and intestines that would lead to vomiting
    and bloody diarrhea. Eventually, the person’s liver, spleen, and kidneys
    might stop working, and the person could die.


  • Injection:
    Injection of a lethal amount of ricin at first would cause the muscles
    and lymph nodes near the injection site to die. Eventually, the liver,
    kidneys, and spleen would stop working, and the person would have massive
    bleeding from the stomach and intestines. The person would die from
    multiple organ failure.


  • Death from ricin
    poisoning could take place within 36 to 48 hours of exposure, whether
    by injection, ingestion, or inhalation. If the person lives longer than
    5 days without complications, he or she will probably not die.

How Is Ricin Poisoning Treated?

  • No antidote exists
    for ricin. Ricin poisoning is treated by giving the victim supportive
    medical care to minimize the effects of the poisoning. The types of
    supportive medical care would depend on several factors, such as the
    route by which the victim was poisoned (that is, by inhalation, ingestion,
    or injection). Care could include such measures as helping the victim
    breathe and giving him or her intravenous fluids and medications to
    treat swelling.

How Do We Know for Sure Whether People Have Been Exposed to Ricin?

  • If we suspect that
    people have inhaled ricin, a possible clue would be that a large number
    of people who had been close to each other suddenly developed fever,
    cough, and excess fluid in their lungs. These symptoms could be followed
    by severe breathing problems and possibly death.
  • No widely available,
    reliable test exists to confirm that a person has been exposed to ricin.

What Can People Do If They Think They May Have Been Exposed to

ricin poisoning is highly unlikely. CDC has no reports of intentional
ricin poisoning. If people think they might have been exposed to ricin,
however, they should contact the regional poison control center at 1-800-222-1222.

How Can People Get More Information About Ricin?

can contact one of the following:

  • Regional poison
    control center (1-800-222-1222)
  • Centers for Disease
    Control and Prevention Public Response Hotline (CDC)

    • English (888)
    • Español (888)
    • TTY (866) 874-2646

  • Agency for Toxic
    Substances and Disease Registry (ATSDR) (1-888-422-8737)