Ricin

Ricin is a poison found naturally in castor beans. If castor beans are chewed and swallowed, the released ricin can cause injury. Ricin can be made from the waste material left over from processing castor beans. 

It can be in the form of a powder, a mist, or a pellet, or it can be dissolved in water or weak acid. It is a stable substance under normal conditions, but can be inactivated by heat above 80 degrees Centigrade.  

Accidental exposure to ricin is highly unlikely, except through the ingestion of castor beans – it would take a deliberate act to make ricin and use it to poison people. If made into a partially purified material or refined into a terrorist or warfare agent, ricin could be used to expose people through the air, food, or water. Ricin poisoning is not contagious. It cannot be spread from person to person through casual contact.