Related Rule
Colombia
Practice Relating to Rule 72. Poison and Poisoned Weapons
Colombia’s Basic Military Manual (1995) prohibits the poisoning of water. 
Colombia, Derecho Internacional Humanitario – Manual Básico para las Personerías y las Fuerzas Armadas de Colombia, Ministerio de Defensa Nacional, 1995, p. 49.
Colombia’s Operational Law Manual (2009) states:
4. Rules for the conduct of hostilities
c. Restrictions on the means and methods
The means and methods of warfare that can be used are limited. Weapons that cause superfluous injury or unnecessary suffering are prohibited. The general principles on the use of weapons establish that “the use of means and methods of warfare which are of a nature to cause superfluous injury or unnecessary suffering is prohibited”. Likewise, “the use of weapons which are by nature indiscriminate is prohibited”.
In this sense, the use of the following weapons is prohibited:
- poison[.] 
Colombia, Manual de Derecho Operacional Manual FF.MM. 3-41 Público, Primera Edición 2009, Comando General de las Fuerzas Militares, aprobado por el Comandante General de las Fuerzas Armadas por Disposición Número 056, 7 December 2009, pp. 40 and 53–54.
[footnotes in original omitted]