Ricin, one of the byproducts of processing castor beans, is a toxin that is fatal to humans in extremely small doses.

Just 1 milligramof ricin is a deadly amount if inhaled or ingested, and only 500 micrograms of the substance would kill an adult if it were injected (CDC). The victim can die within 36 to 48 hours due to the failure of the respiratory and circulatory systems. There is no known cure and one molecule of ricin will kill a cell it enters.

Ricin ingestion is not always fatal. Children are at more risk than adults.

Ricin name comes from the castor bean plant (Ricinus communis) – it is present in the mash that is left over after grinding castor beans into oil.

It can be delivered as a powder, a mist or a pill.

Castor bean plant

Ricin is a ribosome-inactivating protein – it irrevocably damages the ribosomes that carry out protein synthesis in cells. The ribosome-inactivating proteins found in the castor bean plant are extremely powerful, and ricin poisoning can do serious damage to major organs.

What happens if I’m exposed?

Ricin can be fatal if it is inhaled, ingested, or injected. While skin or eye contact with ricin can cause pain, it is typically not fatal in that type of exposure.

The initial symptoms of ricin sickness, which may appear anywhere from 3 to 12 hours from the time of exposure, include coughing, fever and stomach pains.

If ingested, main symptoms within the first hours are stomach ache, gastroenteritis, bloody diarrhea and vomiting. If ingested, ricin causes internal bleeding of the stomach and intestines, followed by the failure of the liver, spleen and kidneys, and finally death by collapse of the circulatory Over the course of the first days after exposure, the victim may experience symptoms of dehydration and low blood pressure.

Ricin inhalation can manifest as lung damage, including pulmonary edema (fluid in and swelling of the lungs).

Castor bean seeds

Other possible symptoms include seizures and problems with the central nervous system.

If the exposure is fatal, the victim most likely will die within five days. If death does not occur in that time, the victim will most likely recover. There is no known antidote for ricin poisoning.

If injected, ricin causes the immediate death of the muscles and lymph nodes near the site of the injection. Failure of the major organs and death usually follows.

If a castor bean seed is swallowed whole without damage to the seed coat, it will probably pass harmlessly through the system. But if the coat is chewed or broken, then swallowed, the poison will enter the body.

Medical experts point out that ricin is nowhere near as powerful a killer as anthrax.