International Narcotics Control Board
In addition, of the Convention establishes two categories of controlled illicit drug precursor substances, Table I and Table II. The Commission on Narcotic Drugs has power to decide whether to control a precursor substance, and which Table to place it in. The assessment of the International Narcotics Control Board is binding on the Commission, however, as to scientific matters. A two-thirds vote is required to add a substance to a Table.