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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