Direct-reading methods for workplace air monitoring

Direct-reading methods (DRMs) are valuable tools for detecting and measuring worker exposure to inhalation hazards. A DRM can be either a device or instrument capable of measuring gases and vapors and aerosols such as dusts, fumes, and mists without manipulation of the sample by the user or sending the sample to an offsite laboratory. Devices are those DRMs that are simple, single point in time measurement of exposure. Instruments are DRMs that contain a sampling system, signal-processing electronics, a display system, and a detector. This manuscript will describe the DRMs which may be used to evaluate worker exposure to gases, vapors, and aerosols. The manuscript will also discuss factors to consider when selecting a DRM and recent developments and events related to DRMs.