CNN is reporting that according to a US Defense Official, two pieces of mail sent to the Pentagon tested positive for the toxin Ricin.
The FBI and Pentagon Force Protection Agency have responded and more testing will be done.
Ricin is a highly toxic compound that is extracted from castor beans and has been used in terror plots. It can be used in powder, pellet, mist or acid form.
If ingested, it causes nausea, vomiting and internal bleeding of the stomach and intestines, followed by failure of the liver, spleen and kidneys, and death by collapse of the circulatory system.