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Castor flower and beans used to make Ricin

Ricin Questions and Answers


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 powder, a mist, 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 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. Ricin has some potential medical uses, such as bone marrow transplants and cancer treatment (to kill cancer cells).


How Can You Be Exposed to Ricin?

It would take an intentional 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 or inhalation), 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 greater amount would likely be needed to kill people if the ricin was swallowed. 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 set up to inject a poison ricin pellet under Markov’s skin. Ricin poisoning is not contagious. It cannot be spread from person to person through casual contact.


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. Eventually this is harmful to the whole body, and death may occur. Effects of ricin poisoning depend on whether ricin was inhaled, ingested or injected.


Signs and Symptoms of Ricin Exposure

The major symptoms of ricin poisoning depend on the route of exposure and the dose received, though many organs may be affected in severe cases. Initial symptoms of ricin poisoning by inhalation may occur within eight hours of exposure. Following ingestion of ricin, initial symptoms typically occur in less than six hours.



Within a few hours of breathing in significant amounts of ricin, the likely symptoms would be difficulty breathing, fever, cough, nausea and tightness in the chest. Heavy sweating may follow as well as fluid building up in the lungs. This would make breathing 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. Finally, low blood pressure and respiratory failure may occur, leading to death. In cases of known exposure to ricin, people having respiratory symptoms that started within 12 hours of inhaling ricin should seek medical care.



If someone swallows a significant amount of ricin, he or she would develop vomiting and diarrhea that may become bloody. Severe dehydration may be the result, followed by low blood pressure. Other signs or symptoms may include hallucinations, seizures and blood in the urine. Within several days, the person’s liver, spleen and kidneys might stop working, and the person could die.


Skin and Eye Exposure

Ricin in the powder or mist form can cause redness and pain of the skin and the eyes.


Death from ricin poisoning could take place within 36-72 hours of exposure, depending on the route of exposure (inhalation, ingestion or injection) and the dose received. If death has not occurred in three to five days, the victim usually recovers. Showing these signs and symptoms does not necessarily mean that a person has been exposed to ricin.


How Ricin Poisoning Is Treated

Because no antidote exists for ricin, the most important factor is avoiding ricin exposure in the first place. If exposure cannot be avoided, the most important factor is then getting the ricin off or out of the body as quickly as possible. Ricin poisoning is treated by giving victims 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 victims were poisoned. Care could include helping the victims breathe, giving them medications to treat conditions such as seizure and low blood pressure, flushing their stomachs with activated charcoal (if the ricin has been recently ingested) or washing out their eyes with water if their eyes are irritated.


How Can You Know if You Have Been Exposed to Ricin?

If we suspect that people have inhaled ricin, a potential 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.


How Can You Protect Yourself and What Can You Do If You Are Exposed to Ricin?

  • First, get fresh air by leaving the area where the ricin was released. Moving to an area with fresh air is a good way to reduce the possibility of death from exposure to ricin.
    • If the ricin release was outside, move away from the area.
    • If the ricin release was indoors, get out of the building.
  • If you are near a release of ricin, emergency coordinators may tell you to either evacuate the area or to shelter-in-place inside a building to avoid being exposed to the chemical.
  • If you think you may have been exposed to ricin, you should remove your clothing, rapidly wash your entire body with soap and water and get medical care as quickly as possible.


Removing Your Clothing

  • Quickly take off clothing that may have ricin on it. Any clothing that has to be pulled over the head should be cut off the body instead of pulled over the head.
  • If you are helping other people remove their clothing, try to avoid touching any contaminated areas, and remove the clothing as quickly as possible.


Washing Yourself

  • As quickly as possible, wash any ricin from your skin with large amounts of soap and water. Washing with soap and water will help protect you from any chemicals on your body.
  • If your eyes are burning or your vision is blurred, rinse your eyes with plain water for 10 to 15 minutes. If you wear contacts, remove them and put them with the contaminated clothing. Do not put the contacts back in your eyes (even if they are not disposable contacts). If you wear eyeglasses, wash them with soap and water. You can put your eyeglasses back on after you wash them.

Disposing of Your Clothes

  • After you have washed yourself, place your clothing inside a plastic bag. Avoid touching contaminated areas of the clothing. If you can’t avoid touching contaminated areas, or you aren’t sure where the contaminated areas are, wear rubber gloves, turn the bag inside out and use it to pick up the clothing, or put the clothing in the bag using tongs, tool handles, sticks or similar objects. Anything that touches the contaminated clothing should also be placed in the bag. If you wear contacts, put them in the plastic bag, too.
  • Seal the bag, and then seal that bag inside another plastic bag. Disposing of your clothing in this way will help protect you and other people from any chemicals that might be on your clothes.
  • When the local or state health department or emergency personnel arrive, tell them what you did with your clothes. The health department or emergency personnel will arrange to get rid of it. Do not handle the plastic bags by yourself.


For more information about cleaning your body and disposing of your clothes after a chemical release, see “Chemical Agents: Facts About Personal Cleaning and Disposal of Contaminated Clothing”.


If someone has ingested ricin, do not induce vomiting or give fluids to drink. Seek medical attention right away. Dial 911 and explain what has happened.


For more information visit the Centers for Disease Control and Prevention.

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