chemical warfare "Hydrogen Cyanide" it was also used "Hydrogen Cyanide" according to the OPCW “Hydrogen Cyanide” “Hydrogen Cyanide” "Hydrogen Cyanide" The OPCW's page on Hydrogen Cyanide "Hydrogen Cyanide" chemical warfare "Hydrogen Cyanide" Hydrogen Cyanide - OPCW it was also used it was also used it was also used "Hydrogen Cyanide" chemical warfare f you look it up Hydrogen Cyanide