The data base contains speciation factors for both volatile organic compounds (VOC's) and particulate matter (PM) from a number of source categories. The speciation factors are the weight percent of the individual compounds or elements that make up either total VOC or total PM. By applying these speciation factors the user can estimate compound specific emissions when only total VOC or PM emissions are known. The VOC data base contains approximately 275 profiles from 28 source categories. The PM data base contains approximately 300 profiles from 20 source categories. Source categories are identified by Source Category Classification and compounds are identified by Chemical Abstracts Services number. The data bases have been published in the following two volume report. 'Air Emissions Species Manual Volume I Volatile Organic Compound Species Profiles, second edition,' EPA-450/2-90-001a, January 1990 and 'Air Emission Species Manual Volume II Particulate Matter Species Profiles, second edition,' EPA-450/2-90-001b, January 1990.