Arsenic is probably the most commonly discussed poisons in literature, television, and the movies. Another common toxic substance “tetrodotoxin,” (TTX), is “a poison found in puffer fish and blue-ringed octopuses. It can leave you paralyzed as your body goes through some agonizing reactions. Death comes after six hours of symptoms, and there is no antidote,” the BBC reports.
One deadly chemical – cardiac glycoside digoxin – can be found in a common garden flower, while the deadliest can be seen in many hospitals; just 2kg would be enough to kill everyone in the world. Cardiac glycosides are medicines for treating heart failure and certain irregular heartbeats. Cardiac glycoside overdose occurs when someone takes more than the average or recommended amount of this medication: This can be by accident or on purpose.
Watch this interesting BBC Video for a discussion of the five deadliest poisons known to scientists.