The CD-ROM was developed to be a repository of congener-specific chlorinated dibenzo-p-dioxin/dibenzofuran (CDD/CDF) emission data extracted from original test reports. The database was designed to accommodate facility-based emission data, as well as non-facility based sources (e.g., mobile sources such as automobiles, and area sources such as residential wood combustion). Test reports from various state agencies, trade associations, EPA program offices, and EPA regulatory dockets were consolidated and assimilated into the database. Most of the emission data concern releases to air because few data are currently available on releases to other media. The database contains information that can be analyzed to track emissions of CDD/CDF over time, compare homologue and congener profiles between and among source categories, and develop source-specific emission factors that can then be used to develop emission estimates. In a separate 450-page report, included on the CD-ROM, Inventory of Sources of Dioxin-Like Compounds in the United States, was used to develop a national inventory of annual releases from a variety of sources for two reference years: 1987 and 1995. The database was initially designed as a series of linked, Excel(C) Version 5 'workbooks'. The CD-ROM also contains the database in a Lotus(C) Version 4 format. However, the Lotus version can only be used to view the data and not do the calculations that the Excel version can perform. Each Excel workbook is 'facility-based,' meaning that all emission data for a specific facility are compiled on a single spreadsheet. Typically, facility-specific information and multiple test run data are entered on the 'top' spreadsheet. This spreadsheet is 'linked' to other data containing standard chemical names, abbreviations, and toxic equivalency factors. The database consists of approximately 270 spreadsheet files, distributed among 30 directories and subdirectories.