Chemical, incendiary or bacterial weapons - Art. 7.
Art. 7. (a) The prohibition of the use of chemical weapons shall apply to the use, by any method whatsoever, for the purpose of injuring an adversary, of any natural or synthetic substance (whether solid, liquid or gaseous) which is harmful to the human or animal organism by reason of its being a toxic, asphyxiating, irritant or vesicant substance.
(b) The said prohibition shall not apply:
I. to explosives that are not in the last-mentioned category;
II. to the noxious substances arising from the combustion or detonation of such explosives, provided that such explosives have not been designed or used with the object of producing such noxious substances;
III. to smoke or fog used to screen objectives or for other military purpose, provided that such smoke or fog is not liable to produce harmful effects under normal conditions of use;
IV. to gas that is merely lachrymatory.