相关规则
Burundi
Practice Relating to Rule 74. Chemical Weapons
Burundi’s Regulations on International Humanitarian Law (2007) states that “there are weapons whose use is prohibited … [such as] chemical weapons”. 
Burundi, Règlement n° 98 sur le droit international humanitaire, Ministère de la Défense Nationale et des Anciens Combattants, Projet “Moralisation” (BDI/B-05), August 2007, Part I bis, p. 17; see also Part I bis, pp. 2, 33, 53 and 109.
The Regulations also lists “employing toxic weapons” as a “violation of the laws and customs of war”. 
Burundi, Règlement n° 98 sur le droit international humanitaire, Ministère de la Défense Nationale et des Anciens Combattants, Projet “Moralisation” (BDI/B-05), August 2007, Part I bis, p. 27.
Burundi’s Law on Genocide, Crimes against Humanity and War Crimes (2003) states:
[The following are] considered as war crimes:
B. Other serious violations of the laws and customs applicable in international armed conflicts, within the established framework of international law, namely, any of the following acts:
q) using … asphyxiating, poisonous or similar gases and all analogous liquids, materials or weaponry. 
Burundi, Law on Genocide, Crimes against Humanity and War Crimes, 2003, Article 4(B)(q).
Burundi’s Penal Code (2009) states:
“War crimes” means crimes which are committed as part of a plan or policy or as part of a large-scale commission of such crimes, in particular:
2. … [S]erious violations of the laws and customs applicable in international armed conflict, within the established framework of international law, namely, any of the following acts:
18°. Employing asphyxiating, poisonous or other gases, and all analogous liquids, materials or devices. 
Burundi, Penal Code, 2009, Article 198(2)(18°).