Prohibition of chemical weapons

Poisons and toxic agents have been used through the ages as a method of warfare, although their use has always been widely condemned. Already a century ago, the Brussels Declaration of 1874 and later the Hague Conventions of 1899 and 1907 prohibited the use of poisons and poisoned bullets in warfare, and a separate declaration of the 1899 Hague Convention condemned the use of projectiles the sole object of which is the diffusion of asphyxiating or deleterious gases.