As used in this compilation, the term precursor chemical refers to a compound which is required in the synthetic process and is itself incorporated into the molecule of the target drug. Essential chemicals are required in the synthetic or extraction process but, in most cases, do not become part of the drug molecule. Essential chemicals include solvents, catalysts, oxidizing and reducing agents, acids and bases. The data sheets on each chemical are divided into categories of information: (1) Other Names; (2) Molecular Formula/Weight; (3) CSA (Controlled Substance Act) Code; (4) Harmonized Code; (5) Density, Boiling Point/Freezing Point and Description; (6) Hazards; (7) Illicit Use; (8) Where Controlled or Regulated; (9) Thresholds; (10) Legitimate Uses; (11) Annual Production; (12) Annual US Imports/Exports; (13) Manufacturers; and (14) Remarks. References