The materials included in the inventory are total emitted particulate matter, alkaline TEP, sulfur dioxide, primary sulfate, nitric oxide, nitrogen dioxide, ammonia, and hydrocarbons in nine photochemical reactvity classes (propane and benzene, >C/sub 3/ alkanes, ethylene, >C/sub 2/ alkenes, mono-alkylbenzenes, di/tri-alkylbenzenes, formaldehyde, other carbonyls, and nonreactive). The nominal spatial resolution for point source location is 100 meters. Area source emission rates are estimated by county, and factors are developed to allocate the county-wide emissions to elements of a 1/4/sup 0/ longitude by 1/6/sup 0/ latitude grid system. The inventory also includes stack height, diameter, flow rate, and temperature to calculate point source emission injection height. The inventory contains average diurnal emission rates (eight 3-hour time periods) for weekdays and weekends during each season of the year.