This publication contains the invited papers which were presented at a workshop on asbestos standards jointly sponsored by the Environmental Protection Agency and the National Bureau of Standards and held on October 1-3, 1980. The workshop was divided into five sections: (1) Bulk Materials for Preparation of Asbestos Standards---This section includes descriptions of natural and synthetic materials which have a potential use as standards for asbestos analysis. In addition, it also includes a description of the NBS Standard Reference Materials Program. (2) Standards Preparation---The electron-microscopy preparation procedures for standards mimicking airborne and waterborne asbestos samples are described. (3) Asbestos Analysis for Standards Certification---This section describes analytical procedures and problems associated with the intra- and interlaboratory analyses of asbestos standards. (4) Error Analysis and Statistics---This section describes the statistical considerations which are involved in asbestos standards preparation and analysis. (5) EPA Provisional Method---Current developments and selected problems with the EPA Provisional Method for Electron Microscope Measurement of Airborne Asbestos Concentrations are discussed. The papers include general reviews on each of the subjects as well as specific papers detailing current research efforts.