Spain
Practice Relating to Rule 72. Poison and Poisoned Weapons
Spain’s LOAC Manual (1996) states that the use of “poison and poisoned weapons” is strictly forbidden in any circumstances.
The manual adds: “There also exists an absolute prohibition to poison food and water supplies.”
Spain’s LOAC Manual (2007) states that there is an absolute prohibition on the use of certain weapons, including “[p]oison and poisoned weapons”.