Castor trees, also called castor plants and castor bean plants, are native to Africa. The plant has migrated and now grows as a weed in warm areas all over the world. Castor pants are admired for their beauty and are often intentionally planted in both private gardens and public parks. In areas with cold winters, castor plants are considered an annual and usually do not survive long enough to produce the toxic seeds commonly referred to as beans. Fortunately, with the exception of possible ingestion, accidental exposure to the poison in castor beans is extremely unlikely.
The castor oil harvested from castor beans is perfectly safe for humans. However, the byproduct of harvesting castor oil is an extremely toxic poison called ricin. Ricin is present in the seeds of the castor plant as well as in the castor oil production byproduct.
A single gram of ricin is estimated to be 6,000 times more toxic than cyanide and 12,000 times more toxic than the venom of a rattlesnake.
Pets and Children
Children should be kept away from or very closely supervised around castor plants, as ingesting just four beans can kill an adult. Livestock and pets should also be kept away from castor plans to avoid accidental poisoning.
Ricin poisoning has no known antidote. The best treatment for ricin is supportive care while removing the ricin from the body as quickly as possible.
Ricin can be made into a powder, mist, pellet or dissolved into a liquid.
Bulgarian writer and journalist Georgi Markov was murdered in London when an assassin stabbed him with an umbrella that contained a pellet of ricin in its tip.