Application of porous foams as size selectors for biologically relevant samplers

In recent years it has become accepted that dust sampling instrumentation used to assess airborne exposure to airborne contaminants should sample according to biologically relevant criteria. This article describes progress toward the development of a personal sampling instrument which uses porous foams to select the thoracic and respirable subfractions of the inhalable fraction of total airborne particulate. The new instrument is based on the Institute of Occupational Medicine personal inhalable aerosol sampler and comprises an inhalable entry and two selection foams in series between the entry and the collection filter. Measurements of the foam penetration characteristics and the reproducibility of these characteristics have been carried out. In most cases different samples of the same grade of foam have been shown to be reproducible in their selection characteristics. Where this is not the case a simple quality control method, based on measurements of pressure drop, has been identified. Aitken, R.J.; Vincent, J.H.; Mark, D.: Application of Porous Foams as Size Selectors for Biologically Relevant Samplers. Appl. Occup. Environ. Hyg. 8(4):363-369; 1993.