Schedule 1 of the Chemical Weapons Convention

Schedule 1 substances, in the sense of the Chemical Weapons Convention, are chemicals which are feasible either to be used directly as chemical weapons or in the manufacture of chemical weapons, and which have very limited to no use outside of chemical warfare. These may be produced or used for research, medical, pharmaceutical or chemical weapon defence testing (called "protective testing" in the treaty) purposes but production above 100 grams per year must be declared to the OPCW in accordance with Part VI of the "Verification Annex".

Source: Wikipedia — Schedule 1 of the Chemical Weapons Convention (CC BY-SA 4.0)