DEVELOPMENT OF RESPIRABLE AEROSOL SAMPLERS USING POROUS FOAMS
Resource
AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL v.40 n.6 pp.332-336
Journal
AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL
Journal Volume
v.40
Journal Issue
n.6
Pages
332-336
Date Issued
1998
Date
1998
Author(s)
CHEN, CHIH-CHIEH
Abstract
Workplace aerosols must be sampled to assess the degree of
health hazard caused by the particulate matter. By adjusting
the sampling flow rate, most of the samplers can match the
50% cutoff size, but not the slope of the respirable
convention defined by the American Conference of
Governmental Industrial Hygienists, the International
Organization for Standardization, and the European Committee
for Standardization (CEN). Combinations of foams (or other
porous material) of different nominal sizes (10-100 ppi) and
thicknesses (5-35 mm) were employed to overcome this bias.
A foam disk 25 mm in diameter was placed in an asbestos
sampling cowl. Dioctylphthalate was the liquid test agent.
An aerodynamic particle sizer and an Aerosizer were
calibrated against a settling chamber and were employed to
measure the aerosol number concentrations and size
distributions upstream and downstream of the foams. The
sampling efficiency data showed that the 50% cutoff size
could be met for foams in series, but that the slope
remained sharper than the new definition. Foams in parallel
showed great flexibility and many of the parallel
combinations flattened the slope, closer to that of the new
international respirable convention. For instance, when the
total flow rate is set at 10.1 L/min the aerosol penetration
through foams in parallel (100 ppi, 20 mm thick, diameter
25 mm + 10 ppi, 20 mm thick, diameter 13 mm) nearly matched
the new international standard for respirable fraction. This
sampler can be further miniaturized for smaller sampling
flow rates to fit the capacity of personal sampling pumps.
Subjects
aerosol exposure
foam samplers
international standardization
Type
journal article