What is ricin toxin?

Ricin is a proteinic cytotoxin derived from the common castor bean, Ricinis communis. Recovered from the meal of castor beans in the castor oil making process, ricin toxin is perhaps 1,000 fold less toxin that botulinum toxin. Ricin is most toxic if inhaled and least toxic if swallowed. It has the potential to be used as a chemical warfare agent.