Measurements of airborne particle concentrations and settle plate counts resulting from the use of a boot scrubber are presented and compared with predictions from two models; one from [Gosman, A. D., Ioannides, E. (198 1). Aspects of computer simulation of liquid fuelled combustors. American Institute of Aeronautics and Astronautics 19th aerospace science meeting, St. Louis, MO, 1215 January, 1981, AIAA paper no. 81-0323; Journal of Energy (ISSN 0146-0412), 7, 482-490] and the other from [Reynolds, A. M. (1998). Modelling particle dispersion within a ventilated airspace. Fluid Dynamics Research, 22, 139-152.]. Both models predicted very high counts within 2m of the scrubber with much lower counts elsewhere within the room. These patterns were in agreement with measurements. Both models also predicted the positions of highest microbial counts in a room where the scrubber had been operated but they both over-predicted the actual counts probably because not all of the organisms put into the scrubber became airborne. Measured clearance times of the airborne particles were around 50-60 min. Reynolds' model predicted such values whereas Gosman and Ioannides' model predicted times below 12min and consequently Reynolds' model is preferred. © 2004 Elsevier Ltd. All rights reserved.