Testing personal inhalable aerosol samplers: a suggested improved protocol based on new scientific knowledge.

In 2002 the Comité Européen Normalisation (CEN) published its document Workplace atmospheres-assessment of performance of instruments for measurement of airborne particle concentrations (EN 13205) that describes a standard protocol by which to carry out the testing and validation of personal aerosol samplers of the type widely used for occupational aerosol exposure assessment. It emerged from more than a decade of discussion and a large body of research experience involving several laboratories. The protocol that is described, however, still poses significant technical and economic challenges, not least because it involves laborious-and hence costly-procedures in large, specialized wind tunnel facilities. More recent research has identified a number of areas by which the protocol may be improved and made more accessible to testing laboratories, including a set of validated aerosol sampler scaling laws, a better understanding of the reduced role of the bluff body of the wearer on sampler performance, and the availability of new options for rapid sampler testing methods. Taking these into account, a dummy new protocol is offered for discussion.