|The purpose of this manual is to assist investigators in developing methods for occupational exposure assessments for electric and magnetic fields (EMF). Scientific reports that associate EMF with increased risks of various diseases have led to exposure assessments for the purposes of research, source assessment, and the surveillance of worker exposures. To provide guidance for these studies, methods that have been used successfully to measure EMF are summarized and presented in a standard format. The scope of the manual is methods for measuring occupational EMF with frequencies below 30 kHz. This covers most fields resulting directly from DC or 50/60 Hz AC electricity, as well as common electric and electronic equipment such as Video Display Terminals (VDT). In this manual, exposure assessment protocols are classified either as complete methods or partial methods. Complete methods are sets of instructions for the sampling strategy, calibration, measurement, data management and calculation of EMF exposure metrics. The exposure metric and other information about the method are contained in a summary table accompanied by a critique of the method’s strengths and weaknesses. Partial methods are essentially parts of a full method that emphasize important aspects of EMF exposure assessments: sampling strategies, spot measurement surveys, personal monitoring, area monitoring, measuring EMF characteristics, measuring EMFs from sources, walkthrough monitoring, quality control, calibration, data management, and calculating exposure metrics. By combining aspects of these complete and partial methods, industrial hygienists and other investigators can assemble protocols specifically tailored to assess EMF exposures for different purposes, applications, and work environments.