Studies into size-fractionated sampling of dusts by means of polyurethane

Status:

completed 12/1996

Aims:

EN 481 "Workplace atmospheres: Size fraction definition for measurement of airborne particles", which has been in force since Autumn 1993, defines three relevant fractions with regard to the effect of dusts on the human respiratory tract: inhalable, thoracic and respirable. Accordingly, the sampling of airborne particles requires equipment which permits simultaneous measurement of these three fractions. At present, no suitable sampling equipment exists, with the exception of cascade impactors. The sampling systems currently available for use on test subjects are generally so limited in their air throughput as to entail unfavourable detection limits and long sampling durations. J. Vincent et al. have proposed a new measurement concept based upon the filtration properties of different porous polyurethane (PU) foams. Compared to filter materials used in the past, suitable PU foams permit both higher air throughputs, and fractionated particle filtration. This concept is to be tested for its suitability and for its use in the BGMG hazardous substances measurement system.

Activities/Methods:

Foams may be employed as size-selective elements for the sampling of particles in workplace atmospheres. They must be adapted in their porosity and geometric dimensions such that particle filtration satisfies the criteria of EN 481 "Workplace atmospheres: Size fraction definition for measurement of airborne particles".

Results:

The implementation of EN 481 may necessitate new sampling equipment in future for assessment of the dust situation at workplaces. The development described and a follow-up project (1058, development of a size-selective personal air sampling system using porous foams) provide a means by which dust sampling may be performed in the workplace atmosphere in compliance with the standards.

Further informations:

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