SPECIAL PART
XVII C H A P T E R S E V E N T E E N
CRIMES AGAINST HUMANITY AND VALUES PROTECTED BY INTERNATIONAL LAW
Violating the Laws and Practices of Warfare
Article 179
(2) Violations of laws and practices of warfare referred to in paragraph 1 of this Article shall include:
a) Use of poison gases or other lethal substances or agents with the aim to cause unnecessary suffering;
Employing asphyxiating, poisonous or other gases, and all analogous liquids, materials or devices - IAC
Employing poison or poisoned weapons - IAC
Employing weapons, projectiles and materials and methods of warfare which cause superfluous injury or unnecessary suffering - IAC
EDIT.