Since 1970 when the U.S. Environmental Protection Agency (EPA) was given the responsibility of regulating all aspects of pesticides, the Agency has amassed, through the registration process, an extensive computer data system on most Federally registered pesticide products. The information includes product names, manufacturers' names and addresses, active chemical ingredients, tolerances for residues, and site and pest information for particular products and active chemical ingredients. Set A contains the Product Manager assignments; Pesticide Products, numerically and alphabetically; Pesticide Companies, numerically and alphabetically, Chemical Reference file, alphabetically and numerically; Tolerance File by chemical and commodity; inverted Chemical/Registration Number; and Pesticide Label Data. Set B contains Site/Pest Data organized into the site name/pest name/chemical/registration number and chemical/site name/pest name/registration number fiche sets. Each set is further divided into the five major pesticide disciplines: herbicides, algaecides and growth regulators; antimicrobials and protozoa; insecticides, acaricides, molluscicides and antifouling compounds; fungicides and nematicides; and rodenticides and technical grade chemicals.