Abstract
The collection efficiency for submicron particles of an all-glass impinger, under conditions commonly used by industrial hygienists, was studied by measuring the removal of particles from a polydisperse polystyrene aerosol. Collection efficiencies for water and dimethylformamide as sampling liquids at flow rates of 0.7, 1.0, and 2.0 L/min were determined. The collection efficiency at a flow rate of 1.0 L/min was found to be less than 20% for particles with a diameter between 0.02 and 0.7 µm. When thermally generated particles are a part of the exposure pattern and air measurements are made using the all-glass midget impinger as the collection device, the particulate contribution to the exposure could be severely underestimated due to poor collection efficiency in the submicron range.