Mustard gas remains undestroyed in Libya TRIPOLI, Libya, Jan. 20 (UPI) -- Organization for the Prohibition of Chemical Weapons officials in Libya confirmed the country has a stockpile of sulfur mustard that has yet to be destroyed. OPCW inspectors visited Libya Jan. 17-19 to verify munitions formally declared last year as well as previously undisclosed chemical weapons, the organization said in a statement. The OPCW inspectors verified the chemical weapons, which included sulfur mustard agent that is not loaded into munitions, as well as artillery shells. Libya joined the OPCW in 2004 under the leadership of ousted leader Moammar Gadhafi, RIA Novosti reported. Since then, the country has destroyed about 55 percent of its declared 1.4 tons of raw materials to produce chemical weapons and 25 tons of mustard gas. The disposal process was halted when the uprising to oust Gadhafi began. The country still has to destroy 11.25 tons of mustard gas. Libya now has until April 29 to submit a detailed plan and date by which the remaining chemical weapons will be destroyed, the BBC reported.