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Poison From Castor Beans

Toxic hazard flag image by Stasys Eidiejus from

Castor bean plants are prized for their aesthetic value in the home garden, but they come with a hefty warning. Castor beans are highly toxic--they contain the deadly poison ricin--and can kill if ingested and will cause irritation when touched.


The castor bean plant (Ricinus communis) is a perennial shrub with multi-lobed, toothed leaves and tiny green, clustered, inconspicuous flowers. In August and September, the fruit reaches maturity, displaying seedpods that reach approximately 1 inch in diameter. The seeds within the pods contain toxins. Castor bean plants grow best in USDA hardiness zones 9 to 11, according to the Washington State University Clark County Extension.


Castor beans contain the deadly toxin ricin. The amount it takes to kill an adult may be as little as 1 milligram, according to the Cornell University Department of Animal Science. Once ingested, ricin is absorbed by the intestines and enters the blood stream; symptoms appear within three hours. The toxins within the castor beans are toxic to people as well animals and insects, according to the Cornell University Department of Animal Science. While there is the possibility of skin irritation due to contact with plant sap, the main cause of poisoning is ingestion.


Take extreme caution when gardening with this plant. Since castor beans fall from the plant to the ground, pay particular attention when gardening around small children and pets. Always wear gloves when handling the plant and employ the use of a net to prevent the beans from dropping, suggests the Washington State University Clark County Extension. Castor bean plants are commonly used as privacy hedges, so take pedestrians and wildlife into consideration. Call 911 immediately if ingestion occurs.


Within the first few hours of ingestion, expect vomiting, diarrhea sometimes accompanied by blood, abdominal pain and weakness. Within a few days, dehydration occurs due to fluid loss and urine production lessens. Blood pressure often drops and an individual may feel fatigued and depressed.


Seeds that are swallowed whole without any incision from chewing or peeling may not prove toxic, as the ricin is within a seed coat that cannot be digested. Due to the high toxicity of ricin, however, contact a physician to prevent accidental poisoning.

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