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, manufactures' names and addresses, active 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.