This tape is a computer readable version of the production and plant site information associated with the Toxic Substances Control Act (TSCA) Chemical Substance Inventory: Initial Inventory. For a complete understanding of the data contained on this tape it is necessary to read the introductory material in the hardcopy version. This description will only touch on a few important points. This tape contains two major sections. The first section is a file describing the production or importation volumes of each chemical at each plant. The second section is a file containing information describing the plants that manufacture or import the chemicals in the inventory. On this tape, chemicals are identified only by CAS Registry Number.