Castor beans are the source of the poison called ricin, but they are also the source of castor oil and other products. You can hold the seeds in your hand and grow the plants in your garden to repel pests.
Ricin is made of two protein chains linked by a disulfide bond. The A chain (blue) is an N-glycoside hydrolase that inhibits protein synthesis. The B chain (orange) is a lectin that helps ricin bind to a cell.
The castor bean, source of ricin, is a popular ornamental garden plant. The plant deters common pests, such as moles.
Ricin is a potent toxin extracted from castor beans. There is a lot of fear and misinformation associated with this poison. The purpose of this fact sheet is to help separate fact from fiction regarding ricin poisoning.
What Is Ricin?
Ricin is a protein that is naturally found in castor beans (Ricinus communis
). It is so powerful a poison that the US Centers for Disease Control (CDC) estimate the lethal dose in humans is about the size of a grain of salt (500 micrograms injected or inhaled).
How Is Ricin Used as a Poison?
Ricin is poisonous if it is inhaled, eaten, or injected. It can be dissolved in water or weak acid and added to a drink. It is not absorbed through the skin, so simply touching ricin or getting ricin powder in your eyes will not cause poisoning.
What Are the Symptoms of Ricin Poisoning?
Symptoms of ricin poisoning show up a few hours after exposure. The symptoms depend on the route of exposure.
Symptoms from ricin inhalation would include coughing, shortness of breath, and nausea. Fluid would begin to accumulate in the lungs. Fever and excessive sweating would be likely. Low blood pressure and respiratory failure could lead to death.
Eating or drinking ricin would produce cramping, vomiting, and bloody diarrhea leading to extreme dehydration. Bleeding from the stomach and intestines would occur. The victim may experience hallucinations, seizures, and bloody urine. Eventually (usually after several days) the liver, spleen, and kidneys could fail. Death would result from organ failure.
Injected ricin produces swelling and pain in the muscles and lymph nodes near the site of the injection. As the poison worked its way outward, internal bleeding would occur and death would result from multiple organ failure.
How Is Ricin Poisoning Detected and Treated?
Ricin poisoning is not easy to detect, but it is not necessarily fatal, even though it is unlikely medical staff would identify the underlying cause. Treatment addresses the symptoms of ricin poisoning and includes helping the victim breathe and administering intravenous fluids to combat dehydration and low blood pressure. Death usually occurs 36-48 hours after exposure, but if a victim survives approximately 5 days, he has a good chance of recovering. Victims of ricin poisoning typically sustain permanent organ damage.
How Does Ricin Work?
Ricin inactivates the ribosomes in cells making them unable to produce proteins. Cells need these proteins to survive and reproduce, so when ribosomes are inactivated, cells die.
What Should You Do If You Suspect Ricin Poisoning?
If you believe you have been exposed to ricin you should move away from the location of the poison. Seek immediate medical attention, explaining to the medical professional that you believe you were exposed to ricin and the circumstances of the event. Remove your clothing. Cut off clothing rather than pulling it over your head, to minimize further exposure. Remove and discard contact lenses. Glasses may be thoroughly washed with soap and water and re-used. Wash your entire body with soap and water.