Binary chemical weapon

Binary chemical weapons or munitions are chemical weapons which contain the toxic agent in its active state as chemical precursors that are significantly less toxic than the agent. This improves the safety of storing, transporting, and disposing of the weapon. Commonly, firing the munition removes a barrier between two precursors. These react to form the intended agent which is then aerosolized and distributed by a bursting charge.

Binary chemical weapons are chemical weapons within the scope of the Chemical Weapons Convention and therefore their production, use and stockpiling is forbidden in most countries, as at least one of the individual chemicals is likely to be a Schedule 1 chemical for which large scale production is forbidden.