ERRORS IN INHALABLE DUST SAMPLING FOR PARTICLES EXCEEDING 100 MU-M

The sampling convention for inhalable dust (inhalability), proposed by the Comite Eurupeen de Normalisation and the American Conference of G overnmental Industrial Hygienists; is undefined for particle sizes lar ger than 100 mu m owing to experimental difficulties in its measuremen t. This paper estimates lower and upper envelopes for the inhalability of these larger particles, for the low air velocities predominating i n indoor work places. Estimates of the inhalable aerosol mass of parti cles exceeding 100 mu m are then obtained for the workplace particle s ize distributions published in the literature. For the reported workpl ace aerosol size distributions, it is generally found that where the m ass median aerodynamic diameter is smaller than 25 mu m the inhalable mass above 100 mu m is negligible. Limitations in the applicability of the laboratory-determined inhalable convention to workplace sampling situations are discussed.