United States
Environmental Protection
Agency
National Exposure
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/SR-96/001 March 1996
4>EPA Project Summary
Evaluation of Dust Samplers for
Bare Floors and Upholstery
J.W. Roberts, W. Han, and M.G. Ruby
The high volume small surface sam-
pler (HVS3) has been validated for mea-
suring lead, pesticides, PAHs, and
PCBs in dust in carpets. This is de-
scribed in ASTM method D5438-94.
However, a reliable method is needed
for measuring dust and the pollutants
in dust on bare floors and upholstery
to estimate exposure from such sourc-
es. The full report describes tests us-
ing the new high volume furniture
sampler (HVFS) to collect dust from
ten used sofas, test pillows with flat
and plush covering, and bare floors. A
high efficiency particle filter was used
after the cyclone in three tests to de-
termine the penetration of the cyclone
by couch dust. Particles above 5 urn
are captured in the cyclone. Less than
0.22% of the dust penetrated the cy-
clone used on the HVFS. A prototype
High Volume Tripod Sampler (HVTS)
was tested on bare floors and carpets,
as well. The Baltimore R&M Cyclone
Sampler (BRMCS) was also tested.
The HVS3, HVTS, HVFS, and BRMCS
all had similar average efficiencies on
bare floors or surfaces ranging from
84.2 to 86.7%. The HVFS cyclone with
a flexible wand and a notched nozzle
showed an average dust collection ef-
ficiency of 88.6 to 90.5% on light and
heavy loading on foam cushions cov-
ered with flat and plush coverings. The
HVTS had an average efficiency of 62%
on plush carpet and 64.5% on level
loop carpet on plush and flat uphol-
stery. The BRMCS had a collection effi-
ciency of 44.1% on plush and 61% on
level loop carpet as well as 71.8% and
87.2% on plush and flat upholstery.
Methods for sampling bare floors and
upholstered furniture were developed.
The HVS3 and HVFS provide a reliable
method of sampling bare floors and
upholstered furniture. The BRMCS is a
reliable way to sample bare floors. The
HVTS and BRMCS are lower in cost
than the HVS3 but have limitations for
sampling carpets.
The full report was submitted in ful-
fillment of Subcontract 46534(g217338-
02)-0003EQ between Battelle Memorial
Inst. and Engineering Plus, Inc. This
report covers the period between Janu-
ary 3, 1993, and Sept. 30, 1993. Work
was completed as of Sept. 30, 1993.
This Project Summary was developed
by EPA's National Exposure Research
Laboratory, Research Triangle Park, NC,
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
the back).
Introduction
House dust is recognized as an impor-
tant source of potential exposure to aller-
gens, lead, pesticides, and other pollutants
in the home. The dust in a rug or couch
and on a bare floor may also contribute to
personal exposure to airborne particles,
allergen, and other pollutants. The High
Volume Small Surface Sampler (HVS3) is
widely used to collect house dust samples
for chemical analysis. Detailed tests have
shown the HVS3 to be useful in sampling
rugs for lead and semi-volatile organic
compounds, specifically pesticides, poly-
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cyclic aromatic hydrocarbons (PAHs), and
polychlorinated biphenyls (PCBs).
Evaluation of the Need for a
Filter in the Sampling Train for
Upholstery Dust
The HVS3 collects its sample in a cy-
clone. It has been previously shown that
over 99% of rug dust is collected in the
cyclone. In order to determine the collec-
tion efficiency of the cyclone on couch
dust, a particle filter was placed in the
sampling train behind the cyclone for a
series of three tests of dust collection from
upholstered furniture. The average weight
of the dust on the filter was less than
0.22% of the total catch on three tests.
The remaining study was conducted with-
out the filter in the system.
Validation Tests of the HVS3,
HVTS, HVFS, and Baltimore
R&M Cyclone Sampler for
Sampling Bare Floors and
Upholstery
Bare Floors
Based on previous testing, two loadings
of 0.1 and 0.5 g/m2 were selected to rep-
resent light and heavy loading conditions
for application of dust to a bare floor for
testing the HVS3. A combined house dust
which had been collected from a number
of Seattle homes, sieved through a 100
mesh screen (< 150 urn), and finally mixed,
was spread on a cleaned section of an
asphalt tile floor and, subsequently, a var-
nished wood floor. The surface was then
sampled with the HVS3.
A modification of the HVS3, called the
High Volume Tripod Sampler (HVTS), was
designed by Cascade Stack Sampling Sys-
tems to minimize air currents next to the
floor. This modification had the same
nozzle and cyclone as the HVS3. This
prototype of a floor sampler suspends the
sampling head from a wheeled tripod and
powers it with a portable vacuum cleaner
that can be slung over the shoulder. A
four horsepower (10.0 amp) Royal Can
Vac™, Model 3004 canister vacuum
cleaner was used to move air through the
HVTS. The Can Vac weighs 9 pounds
and the HVTS weighs 13 pounds.
The average efficiency of the HVTS for
the same light and heavy dust loading
was 84.2 and 85.1%, which on bare floors
is nearly the same as with HVS3 (86.7
and 84.8% respectively). The HVTS was
also tested on carpets, and the results
averaged 62% for plush and 64.5% for
level loop. The carpets were plush and
level loop test carpets meeting the ASTM
method F655-89 standards. The recovery
rate of the HVTS is less than the 67 to
69% recovery rate of the HVS3.
Upholstery Sampling
The HVFS upholstery sampler with a
notched nozzle and flexible wand was de-
signed by CSS. The same Royal Can
Vac™ used with the HVTS was used to
move air. This design preserves the es-
sential elements of the HVS3, although it
was necessary to modify the nozzle to
avoid sealing to the fabric being sampled.
Two popular coverings of couch cush-
ions, a flat poly-cotton (53% cotton and
47% polyester) and a velvet (65% cotton
and 35% polyester), were selected for test-
ing. Each cushion was built around a high
density polyurethane foam core. The air
flow through the HVFS was adjusted to
14.4 L/S (30.5 CFM) and the pressure
drop across the nozzle to 10.2 cm (4
inches) water gauge for the flat poly-cot-
ton cushion. The air flow was set at 11.6
L/S (24.5 CFM) and the pressure drop
across the nozzle at 31.8 cm (12.5 inches)
water gauge for the velvet cushion. The
light and heavy surface loadings of 2.5
and 5.6 g/m2 for sampling were selected
on the basis of the loadings found on ten
used sofas. The dust was placed in a
45.7cm x 45.7cm (18"x18") square on the
cushion and embedded with a 34 pound
mallet. The dust collection efficiency of
the HVFS furniture sampler is shown in
Table 1. The average efficiency of dust
collection varied within a range of 87 to
90% for light and heavy loadings on vel-
vet and flat cushions.
Comparative Tests
The Baltimore R&M Cyclone Sampler
(BRMCS) was developed by the Kennedy
Krieger Institute as a sampler for window
sills and similar hard surfaces.
The BRMCS uses the same cyclone as
the HVS3 with a one-inch Tygon® tubing
flexible sampling wand and nozzle. The
nozzle consists of a notched end on the
Table 1. Efficiency of Dust Samplers
tube. A Royal Hand Vac™, Model No. 553
(2.0 amp), is used to move air. A paper
bag was used in the Royal Hand Vac™ in
the conventional way. The BRMCS was
tested on a bare wood surface, uphol-
stery, and carpets using a modified ASTM
method F609-89. The protocol used for
collecting dust with the BRMCS and the
HVFS were developed for the University
of Rochester lead dust study by the Na-
tional Center for Lead Safe Housing. The
BRMCS had an average collection effi-
ciency of 84.7% on bare floors, 71.8 and
87.2% on velvet and flat upholstery, as
well as 44.1% on plush and 61% on level
loop carpet.
Sampling Upholstery for Dust,
Lead, Organic, and Allergens
The samples collected from the ten used
sofas were sieved through a 100 mesh
screen and analyzed for total dust, fine
dust, lead, organic, and allergens. The
samples were collected with the HVFS
furniture sampler followed by a Hoover
Brush Vac™, Model No.S1137, with a
power-driven brush in the nozzle. Each
surface that was sampled was passed
over eight times in two directions with
each sampling nozzle. The HVFS collected
72.4 grams and the Hoover Brush Vac™
collected 80.4 grams of total dust from the
sofa cushions. The HVFS and Brush Vac
dust samples from each couch were com-
bined before sieving.
The lead was analyzed using EPA
method SW846 with flame atomic absorp-
tion. The couch fine dust lead concentra-
tions ranged from 130 to 380 |ig/g with an
average of 229 |ig/g.
Dust mite allergens in a combined
sample were measured at 11.1 |ig/g for
D. Pteronyssinus (Der p I) and 5.2 |ig/g
for D. Farinae (Der f I). Above 10 |ig/g is
considered a high exposure for mite aller-
gen. Cat allergen was measured at 37.2
|ig/g for F. domesticus (Fel d I). Above 8
|ig/g is considered a high exposure for cat
allergen.
HVS3
Bare Floor 85% —87%
Rugs
Plush
LL
Upholstery
Velvet
Flat
69%
67%
NA
NA
HVTS
84%— 85%
62%
65%
NA
NA
HVFS
84%
NA
NA
87%— 90%
89%— 91%
BRMCS
85%
44%
61%
72%
87%
LL=Level Loop
NA= Not Applicable
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Results and Discussion
Validated methods of sampling of up-
holstered furniture and bare floors are nec-
essary to estimate exposure. The three
devices (HVS3, HVTS, and BRMCS)
tested were equally effective (84.2 to
86.7% efficiency) in collecting dust from
bare floors. The HVFS with a cyclone,
wand, and notched nozzle was effective
in sampling upholstery and collected 88.6%
to 90.5% of the dust applied to cushions.
Using the cyclone currently used on the
HVS3 on the other samplers allowed high
air flows that were unaffected by the size
of the sample collected. A large represen-
tative sample can usually be collected in
ten minutes. The cyclone allowed less than
0.22% of the total couch dust to pass.
The prototype HVTS and the BRMCS
are both lower in cost than the HVS3 but
have their limitations. The HVTS can be
used effectively on bare floors and hard
surfaces. The HVTS efficiency on carpets
was 5% below that of the HVS3. The
BRMCS is lowest in cost, easier to carry,
and can be used to sample bare surfaces
effectively. Its efficiency on velvet and flat
cotton-poly cushions was 71.8 and 87.2%
respectively. Its efficiency on plush and
level loop carpet was 44.1 and 61% re-
spectively. It has no way to monitor a
drop in air flow due to blinding of the bag,
leaks or motor wear. It will also take longer
to acquire a representative sample from a
carpet.
It is easier to sample for, and may be
more effective to monitor exposure to many
toxic substances, by monitoring house dust
rather than indoor or outdoor air. There is
also a need to continuously improve the
cost effectiveness of such sampling meth-
ods. The two lower cost dust sampling
methods evaluated in this study (i.e., the
HVTS and the BRMCS) have potential
and with additional development work can
contribute to effective exposure analysis
on rugs and upholstery as well as bare
surfaces. New procedures are provided in
the full report for sampling bare floors,
hard surfaces, and upholstered furniture.
Conclusions and
Recommendations
This study has demonstrated that the
HVS3 can obtain a reliable sample of dust
from bare floors. The efficiency of all the
samplers on bare floors, rugs, and uphol-
stery are shown in Table 1. Two lower
cost samplers, the prototype HVTS and
BRMCS were also evaluated. The HVS3,
HVTS, and BRMCS all had similar aver-
age efficiencies on bare floors or surfaces
ranging from 84.2 to 86.7%. The HVFS
showed an average dust collection effi-
ciency of 88.6 to 90.5% on light and heavy
loading on foam cushions covered with
flat poly-cotton and velvet coverings. The
HVTS had an average efficiency of 62%
on plush carpet and 64.5% on level loop
carpet. The BRMCS had a collection effi-
ciency of 71.8 and 87.2% on velvet and
flat upholstery as well as 44.1% on plush
and 61% on level loop carpet. The effi-
ciency of the HVTS is less than that ob-
tained by the HVS3 but consistent across
carpet types. The BRMCS is not suffi-
ciently consistent with surfaces other than
bare floors and hard surfaces. However,
both the HVTS and BRMCS represent an
important advance and can be expected
to improve with further development. The
method for sampling carpets has been
revised to include bare floors. A new
method for sampling furniture is also in-
cluded in the appendix of the full report.
The dust loading found in ten used so-
fas delivered to the Seattle Salvation Army
collection station ranged from 0.95 to 12.27
g/m2 for total dust and 0.11 to 4.9 g/m2 for
fine dust (< 150 micrometers). The lead
concentration in this dust averaged 229
|ig/g, with a range of 130 to 380 |ig/g. A
combined sample of couch dust contained
a high concentration of 16.3 |ig/g and
37.2 |ig/g of mite and cat allergen respec-
tively.
There are several important questions
that remain to be answered to assess and
manage the exposure from pollutants in
dust on bare floors, carpets, and uphol-
stery. We recommend
1. Measuring the lead, pesticides,
PAHs, PCBs, and allergen in up-
holstered furniture and on bare
floors and carpets in a sufficiently
large, representative sample of
homes located in large cities.
2. Documenting the effect of track-in
and dust control as well other clean-
ing techniques on exposure to the
pollutants from upholstered furni-
ture, carpets, and bare floors.
3. Doing additional development work
to improve the cost-effectiveness
of dust sampling devices.
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J.I/I/ Roberts, W. Han, and M.G. Ruby are with Engineering Plus, Inc., Seattle, WA
98112.
Robert G. Lewis is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of Dust Samplers for Bare Floors and
Upholstery," (Order No. PB96-157474; Cost: $21.50, subject to change) will be
available only from
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
National Risk Management
Research Laboratory (G-72)
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use
$300
EPA/600/SR-96/001
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