Aerosol Technology in Hazard Evaluation is the fifth in the series of books on the subject of aerosol technology. This series is organized into nine chapters that cover the properties, sampling, and respirable activity of aerosol. After briefly describing the nature of an inhalation hazard, the book examines the properties, measurement, and significance of geometric diameters of aerosols, as well as the shape factors relating them to various particulate properties. The mathematical description of size distributions and the statistics of sampling from a lognormal distribution of particle sizes are provided. Considerable chapters deal with the methods of aerosol concentration measurement and geometric and aerodynamic size sampling. Operating characteristics of respirable aerosol activity samplers and their limitations are also examined. The concluding chapter discusses problems in the production, flow measurement, apparatus calibration, and isokinetic sampling of aerosols. This series will provide a convenient source of information to those concerned in industrial hygiene and will stimulate the interest of those involved in all phases of environmental health.