Abstract
Study of the air velocities and particle concentrations generated by a typical hand grinder is reported. Motivation for the research is the need to improve the controls for respirable particle emissions generated during hand grinding operations. Present methods of reducing worker exposures, such as high velocity, low volume hoods and helmeted, air-supplied respirators, are either not effective for all types of work to be ground, or involve attention and motivation by the worker for their operation. This description of hand grinder air velocities and particle concentrations has not been reported previously, and should help to improve the understanding of the emission process and to develop the methodology necessary for improving old or developing new controls. The optical particle counter used in this work gives a quantitative indication of particle emission paths and relative concentration and is a good indicator of relative control effectiveness.