The performance of nuisance dust respirators against typical industrial aerosols

There are no standard test protocols available to assess the performance of nuisance dust respirators and there are no published studies describing their actual performance. A series of laboratory tests has been undertaken to determine the filtration efficiency and total inward leakage (TIL) of a range of nuisance dust masks against a common nuisance dust (Portland Cement). Subjective assessment of the fit and comfort of each mask was also made. In general, the filter penetration was less than 7%; only two of the seven masks tested exceeded this figure. The total inward leakages were less consistent; the individual valves ranged from 3.5 to 64% with geometric mean for each mask between 10 and 44%. The masks were often subjectively assessed as uncomfortable, too loosely fitting or too small to adequately cover the nose and mouth. One of the masks was tested against man-made mineral fibre dust. In the tests the filter penetration was considerably lower than observerd with the cement dust. However, the TILs were not significantly different. The poor design of many of the masks tested prompted the authors to construct their own nuisance dust mask from low-cost household items. The performance of this mask was found to be superior to most of those commercially available. It is argued that the introduction of a standard test protocol would provide an incentive to manufacturers of nuisance dust masks to improve the quality of their products.