According to the International Institute of Strategic Studies, Russia has the largest stockpile of chemical weapons, amounting to around 40,000 tonnes (44,092 tons or 8,818,400 lb).
The Russian stockpile is kept in two locations, 7,500 tonnes in one and the remainder in another.
The US, with a declared inventory of 27,768 metric tons of chemical has the second largest stockpile. As of 31 March 2006, however, the U.S. has destroyed 10,103 metric tons of chemical agent since Entry-into-Force of the Chemical Weapons Convention (this equates to 36.4% of its declared inventory).
Comments below may relate to previous holders of this record.