A package containing ricin poison that was addressed to US President Donald Trump has been intercepted before it reached the White House, officials told US media.
Ricin (/ˈraɪsɪn/RY-sin), a lectin (a carbohydrate-binding protein) produced in the seeds of the castor oil plant, Ricinus communis, is a highly potent toxin. A dose of purified ricin powder the size of a few grains of table salt can kill an adult human. The median lethal dose (LD50) of ricin for mice is around 22 micrograms per kilogram of bodyweight via intraperitoneal injection. Oral exposure to ricin is far less toxic. An estimated lethal oral dose in humans is approximately 1 milligram per kilogram.
The letter was discovered at a screening facility for White House mail earlier this week, the officials said.
They said a substance found inside the envelope was identified as ricin, a poison found naturally in castor beans.
The Trump administration is yet to comment on the reports.
The Federal Bureau of Investigation (FBI) and the Secret Service are investigating where the package came from and whether others have been sent through the US postal system.
“At this time, there is no known threat to public safety,” the FBI told CNN in a statement on Saturday.
One official told the New York Times that investigators believe the package was sent from Canada. Reports say the presence of ricin was confirmed after tests by the FBI.
The Royal Canadian Mounted Police (RCMP) said on Saturday it was working with the FBI to investigate the “suspicious letter sent to the White House”.
Ricin is produced by processing castor beans. It is a lethal substance that, if swallowed, inhaled or injected, can cause nausea, vomiting, internal bleeding and ultimately organ failure.
No known antidote exists for ricin. If a person is exposed to ricin, death can take place within 36 to 72 hours, depending on the dose received, according to the US Centers for Disease Control and Prevention (CDC).
The CDC said the toxin – which has been utilized in dread plots – can be produced into a weapon as a powder, fog or pellet.
The White House and other government structures have been the objective of ricin bundles previously.
In 2014, a Mississippi man was condemned to 25 years in jail for sending letters cleaned with ricin to previous President Barack Obama and different authorities.
After four years, in 2018, a previous Navy veteran was accused of sending poisonous letters to the Pentagon and White House.