Ricin toxin is a highly toxic substance that can be deadly if ingested, inhaled, or injected into the body. It is a protein found in the seeds of the castor oil plant, which is native to Africa. Ricin can be used as a biological weapon and has been used in assassinations and terrorist attacks. Synonyms for ricin toxin include castor bean toxin, ricin protein, and toxalbumin. It can also be referred to as castor toxin or simply ricin. Due to its highly toxic nature, ricin is strictly regulated and only authorized personnel are permitted to handle it under controlled conditions.