WHAT IS RICIN? HERE'S WHAT YOU NEED TO KNOW ABOUT THE DEADLY POISON

A woman was arrested at the U.s.-canada border near Buffalo, New York on Sunday, after allegedly sending a ricin-filled envelope to the White House, the RCMP said. Here’s what you need to know about the deadly poison.

Ricin is found naturally in castor beans, which are pressed to make castor oil. The oil, which is used as a traditional remedy for constipation and to induce labour, does not contain ricin. The deadly poison is left behind in the pulp. According to the Bethesda, Maryland-based National Center for Biotechnology Information, someone has died from ingesting just two castor beans.

But ricin is only released if the outer shell of the bean is broken or chewed.

Ricin can also be extracted from castor beans and purified in order to make a potent biological weapon.

Initial symptoms appear within four to 10 hours and may include colicky abdominal pain, vomiting, diarrhea and heartburn.

If prepared properly, ricin can cause death within 36 to 72 hours. No known antidote exists.

Ricin is often found in powder form or in pellets and can also be turned into an aerosol. It is deadliest when it is inhaled. An amount the size of a grain of salt is enough to kill an adult.

Ricin has been sent to politicians and officials in the United States in the past. In 2014, James Everett Dutschke got 25 years in prison for sending ricin to then-u.s. president Barack Obama and two other officials in an effort to frame his rival Paul Kevin Curtis. No one was harmed. The same year, actress Shannon Richardson got 18 years for sending ricin-laced letters to Obama and then New York City mayor Michael Bloomberg in an attempt to frame her husband. The poison was infamously used in the assassination of Georgi Markov, a dissident Bulgarian writer who defected to the West in 1969. He died on Sept. 11, 1978 after an assassin jabbed his thigh with an umbrella while he was waiting for a bus in London.