“The United States recovered thousands of old chemical weapons in Iraq from 2004 to 2009 and destroyed almost all of them in secret and via open-air detonation, according to a written summary of its activities prepared by the Organization for the Prohibition of Chemical Weapons, the international body that monitors implementation of the global chemical weapons treaty.”
Source: Thousands of Iraq Chemical Weapons Destroyed in Open Air, Watchdog Says – NYTimes.com