United States
                Environmental Protection
                Agency
                Research and Development
  Air and {Energy Engineering
  Research Laboratory
  Research Triangle Park, NC 27711

                    November 1994
EPA/600/SR-94/141
r EPA      Project  Summary
                                                    i
                Characterization of
                Emissions  from Carpet  Samples
                Using  a  10-Gallon
                Aquarium as the Source
                Chamber
               Zhishi Quo and Nancy Roache
                  As part of Phase I of a carpet
               bioresponse study sponsored by the
               U.S. Environmental Protection Agency
               (EPA), a study was conducted to evalu-
               ate the emissions from carpet samples
               that had previously shown toxic effects
               on  experimental mice as reported by
               Anderson Laboratories, Inc., Dedham,
               MA, in 1992. The full report describes
               the major findings of the chemical char-
               acterization work conducted at the In-
               door Source Characterization Labora-
               tory of EPA's Air and Energy Engineer-
               ing Research Laboratory. All other re-
               sults (animal testing, microbial testing,
               chemical analysis by  sample extrac-
               tion, and  pesticide analysis) are re-
               ported separately.
                The experimental system used in this
               study was first developed by Anderson
               Laboratories and was identical to the
              system that EPA's Health Effects Re-
              search Laboratory (HERL) used in car-
              pet bioresponse testing. Duplicate tests
              were conducted for each of three -
              samples received from the Consumer
              Product Safety Commission: two previ-
              ously used carpet samples plus mock
              (empty bags) samples.
                An emissions characterization team
              from  Acurex Environmental Corpora-
              tion  evaluated the experimental sys-
              tem  and concluded that the test sys-
              tem developed by Anderson  Laborato-
              ries was not suitable for carpet chemi-
 cal emisisions characterization because
 of poor reproducibility, nonuniform
 thermal conditions, and emissions from
 the source chamber itself. The 1-h bake
 cycle prior to the dynamic mode is not
 typical  of indoor air characterization
 methods.
   This Project Summary was developed
 by EPA's Air and Energy Engineering
 Research  Laboratory, Research  Tri-
 angle Park, NC, to announce key find-
 ings of the research project that is fully
 documented in a separate report of the
 same title (see Project Report ordering
 information at back).

 Introduction
  In 1992, researchers at Anderson Labo-
 ratories,  Inc.,  of Dedham, MA,  reported
 toxic effects in  experimental mice exposed
 to emissions from selected carpet samples
 Because of the potential public health sig-
 nificance of their reported findings, the
 U.S.  Environmental Protection Agency
 (EPA) and the Consumer Product Safety
 Commission (CPSC) initiated studies in
 1993 to evaluate Anderson's experimen-
 tal method and to replicate the reported
 findings.  In addition to a comprehensive
 toxicity screen and microbial characteriza-
tion, the EPA test plan (Phase I) called for
a thorough chemical characterization of
emissions from carpet samples collected
by CPSC. This report summarizes the find-
ings of the carpet emissions characteriza-
                                                            Printedon Recycled Paper

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tion performed by Acurex Environmental
Corporation under EPA Contract 68-DO-
0141 at the Indoor Source Characteriza-
tion Laboratory of EPA's Air and  Energy
Engineering Research Laboratory (AEERL).
  The experimental system used in this
work was based on a protocol provided
by Anderson Laboratories and was identi-
cal to that used by EPA's Health Effects
Research Laboratory (HERL) for replicat-
ing Anderson Laboratories' tests.
  The objectives of the study were two-
fold. First, emissions tests were performed
to Identify potential toxic volatile  organic
compounds in the emissions from carpet
samples and to determine the concentra-
tion levels during the exposure. Second,
 because of the unconventional nature of
 the method, the experimental system was
 characterized to determine test conditions
 and the background emissions from  the
 source chamber.

 Method

 Test System and Protocol
   The test system consisted of four func-
 tional parts: air  supply system, source
 chamber, exposure chamber, and air flow
 control. During a test, the carpet sample
 was placed in the source chamber (a 10-
 gal — 38 L—glass aquarium) and heated
 to elevated temperatures. Humidified zero-
 grade air was then introduced to the cham-
 ber to carry the emissions to the exposure
 chamber, where the experimental animals
  are tested. Air samples were collected for
*  chemical analysis from the source cham-
  ber after the 1-h static period and from
  the exposure chamber during the dynamic
  period.
    Duplicate tests were conducted on each
  of the three carpet samples randomly re-
  ceived from CPSC. Samples A and C
  were previously used carpet samples col-
  lected by CPSC, and Sample B was re-
  ceived as an empty  bag to  indicate an
  empty chamber test. The samples were
  received as follows: Sample A for tests 1
  and 6; Sample B for tests 2 and  3; and
  Sample C  for tests 4 and 5. Each test
  consisted of  four 1-h exposure periods
  and took two days to complete.

   Test Parameters
    The major test parameters were
  Size of carpet sample:         2,900 cm2
   Observed sample
     temperature:                 ~50°C
       (at the surface of the carpet backing)
                                 ~70°C
       (hot spot on the fiber side)
Target air temperature in source
   chamber:                 37 ± 3°C
Observed average air temperature
    in source chamber:          -41 °C
Volume of source chamber:
Source chamber air flow rate:
Target relative humidity of inlet
    air:
    38 L
, 7 L/min


 45 + 5%
 Volatile Organic Compound
 Analysis
   The volatile organic compounds (VOCs)
 were collected on multisorbent traps dur-
 ing chamber testing and analyzed by ther-
 mal desorption-capillary  gas chromato-
 graph (GC) equipped with a mass selec-
 tive detector (MSD) for compound identifi-
 cation and a flame ionization detector (FID)
 for  compound  quantification. Individually
 identified compounds were quantified, and
 the emissions of total volatile organic com-
 pounds (TVOCs) were estimated.
   The VOCs were measured using sam-
 pling and analysis procedures developed
 and implemented  in previous emissions
 testing at AEERL. These procedures in-
 cluded daily tuning of the MSD for identifi-
 cation, five-point calibration of the GC/FID
 for quantification,  analysis of daily check
 samples, analysis of field and laboratory
 blanks,  and verification  of sorbent trap
 background concentrations (blanks).

 Measurements of Particle
  Concentrations
    The instrument  used for monitoring par-
 ticle concentration  was  a model 8010
  PortaCount particle counter (TSI). The in-
  strument was operated  in the "Count
  Mode," in which  the  instrument directly
  counts  the  aerosol  drawn through the
  sample port and  gives the concentration
  in particles per cubic centimeter (P/cm3).
  Particle concentrations between 0 and 5 x
  10s P/cm3 can be measured with this in-
  strument. For comparison purposes,  the
  particle concentrations in the laboratory
  air were measured before and after each
  exposure.

   Results

   Characterization of Physical
   Parameters
     Tracer gas measurements showed that
   the air in the exposure chamber was well
   mixed. The inlet and outlet air flow rates
   were measured with an electronic bubble
   flowmeter at the start of each test to make
   sure the difference between the two flow
   rates was within 10%. Comparison of the
   outlet air flow prior to each exposure and
   after the completion of the test indicated
increased leakiness of the system during
testing due to heated duct tape and poor
seals in the system. The pressure differ-
ence between exposure chamber and the
laboratory air was negligible.
  The source chamber was heated with
heating  pads from  outside, creating a
poorly controlled thermal environment.
Temperature data from 12 locations were
collected at a frequency of one reading
every minute  and logged by a computer.
Figure 1 shows an example of tempera-
ture profiles in the source chamber.

 Total  Volatile Organic
 Compounds
   Peak TVOC concentrations found in the
 source  chambers at the  end of the  initial
 1-h static heating  period  were approxi-
 mately  10 mg/m3 for each carpet sample.
 The background contribution to the TVOC
 concentration from  the  source  chamber
 was <1 mg/m3 arid represented <10% of
 the TVOC during  the carpet test.  Peak
 TVOC  concentrations averaged  2-8 mg/
 m3 in subsequent samples collected from
 the source chamber after the 1-h  static
 periods with the same carpet sample. Each
 exposure followed a pattern of an initially
 high concentration followed by a continu-
 ous decay in concentration during the 1-h
 exposure period 'because of the dilution
 by clean air (Figure 2). During subse-
 quent  1-h exposure periods, the source
 strength  was lower and variable (Figure
 3).

  Individual and Classes of
  Compounds in Carpet
  Emissions
    More  than 200  compounds were ob-
  served in the carpet emissions. About 15%
  were  identified  and  confirmed  by
  interlaboratory comparison  of GC/MS
  analysis, another  70% were  tentatively
  identified, and  the remaining  15% were
  not identified. The identified compounds
  fell into the following  classes: alkanes,
  alkenes, cycloalkanes, cycloalkenes, oxy-
  genated hydrocarbons,  one-  or two-ring
  aromatic hydrocarbons, siloxanes,  and
  phenols. Oxygenated hydrocarbons, aro-
  matic hydrocarbons, and  siloxanes were
  also emitted from an empty source cham-
  ber. Table 1 lists compounds identified by
  Acurex for each  test sample. Table 2
  shows the classes of compounds found in
  the emissions from each sample.
     Concentrations of the predominant com-
  pounds, including those identified by HERL
  as potentially toxic for  each sample, are
   listed in Table 3. The data are the  aver-
   age  concentration from a  60-minute
   sample during Exposure 2 of each test.

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   10-
                          —1—
                           50
                       100
                                                                  Carpet Fiber
                                                                 Carpet Backing
                                                                 Air in Aquarium
                                                                                      Second
                                                                                     Exposure
150
  200      250
Elapsed Time (min)
300
350
—i—
 400
                                                                                                 450
Figure 1. Typical temperature profiles in the source chamber.
                 10000
                                    10    15
                                     20     25    30
                                     Elapsed Time (min)
                          35     40     45     50
Figure 2. Observed TVOC emissions from Sample A (Exposure 1, Test 1).

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          5000-
                            Exp1
                    Exp 2            Exp 3
                          Exposure \D
Exp 4
I     I Sample A     RSSJ Sample B
                                                                       Sample C
  Figure 3.  Average TVOC concentrations in the exposure chamber during four 1-h exposure periods of a test.
Particles
  The particle concentrations in the cham-
ber air were one to two orders of magni-
tude lower than those found in laboratory
air.

Conclusions
  The objective of this study was to char-
acterize the physical parameters of the
test system  and the chemical emissions
from two specific carpet samples and the
empty source chamber under test proto-
col conditions. The experimental  system
used for the physical and chemical char-
acterization was identical to the  system
used by HERL  in their bioresponse test-
ing. Although the experimental systems
were identical in design and materials, the
emissions generated during  testing with
individual systems could be different based
on the following observations:
  • Nonuniform heating  of chamber sur-
    faces,  chamber air,  and  carpet
    samples
  • Development of air leakage in cham-
    bers during testing
  • Emissions  of pollutants from the
    source chamber
                   •  Inadequate temperature control be-
                     cause of low precision manual tem-
                     perature controls
                   The study results indicate that environ-
                 mental conditions could  not be precisely
                 controlled or reproduced. Therefore, there
                 is no assurance  that identical  systems
                 would produce identical emissions.
                   More than 200  compounds were emit-
                 ted by the two carpet samples that were
                 tested. Of the 200 compounds, 29 (15%)
                 were identified by GC/MSD and confirmed,
                 and another 70% were tentatively identi-
                 fied. Of the 29 compounds that were con-
                 firmed,  58% were found in  both  carpet
                 samples tested, and five of the confirmed
                 compounds were  observed in all three of
                 the test samples (two carpets and empty
                 chamber). Most of the emissions from the
                 empty source chamber were siloxane iso-
                 mers  with most of the  emissions  being
                 less than the quantification limits of the
                 analytical instruments.
                   Quantitative differences of some of the
                 individual compounds were observed dur-
                 ing an  exposure, between the four suc-
                 cessive exposure cycles of a single test,
                 and between replicate tests  using differ-
                 ent subsets of the same carpet sample.
     Although the same flow rate and tempera-
     ture protocols were followed throughout
     this study and  replicate subsets of the
     same carpet samples were tested, no two
     exposures produced the same emission
     profile. During  the  exposure period, the
     TVOC  concentration and concentrations
     of some individual compounds decreased
     with time but did not exhibit an exponen-
     tial decay. Some of the predominant highly
     volatile compounds observed in Exposure
     1 were below the detectable limits of the
     analytical systems  in subsequent expo-
     sures.  The emissions from these  tests
     were a function of the exposure protocol
     and the time during the exposure at which
     the samples were collected.
       No evidence was found to support the
     hypothesis that the carpet samples could
     generate a significant amount of particles
     under the experimental conditions.
       The data reported in this document are
     representative  only of  the  two carpet
     samples tested during this study. The car-
     pet samples  evaluated  were  not  new;
     some of the emissions may have been of
     chemicals adsorbed onto  the samples dur-
     ing previous use. ,

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Table 1.  Individual Compounds Identified in the Three Samples
Compound
Sample A
                                                                                 Sample B
Sample C
Acetone
Isopropanol
Benzene
Acetic Acid
Toluene
Hexanal
Ethylbenzene
m,p-Xylene
N,N-Dimethyl-acetamide
Styrene
o-Xylene
a-Pinene
Benzaldehyde
Decane
Trimethylbenzene
Limonene
Acetophenone
Terpene
Undecane
n-Dodecene
Camphor
Naphthalene
Dodecane
Dodecamethylcyclohexasiloxane
4-Phenylcyclohexene
Butylatedhydroxytoluene
Hexadecane
Butanoic acid
2,3-Dihydro-1,1,3-trimethyl-3-phenyl-1H-indene
Table 2.  Classes of Compounds Identified in the Three Samples

Class                                                Sample A
                                                                                  Sample B
                                                          Sample C
 Alkanes
 Alkenes
 Cycloalkanes
 Cycloalkenes
 Oxygenated hydrocarbons
 Siloxanes
 Substituted  benzene
 Substituted phenol

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Tsbte 3.  Predominant Emissions by Test
           (Concentration unit: iig/rrf)

Compound
Sample'/Test A/1
 A/6
B/2
B/3
C/4
C/5
Butylatedhydroxytoluene (BHTf
Acetic Acid*
Naphthalene1
Toluene
Nonanal
Tri(t-butyl) phenol
Phenol
Siloxane isomer
(retention time 59.9 min)
386
14
19
134
49
48
ND
25

407
27
22
10
108
55
ND
32

29
ND
ND
44
ND
ND
ND
6

18
ND
ND
21
ND
ND
ND
4

2
ND
ND
4
53
ND
15
73

21
2
3
7
1693
ND
73
39

TVOCs
            1737
2198
182
115
                                                                                    1890    3181
'Samples: A and C = carpet; B » empty chamber used as a control.
'Identified as potentially toxic by HERL.
"Coelution of nonanal and siloxane isomer.
ND • not detectable by analytical system.

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 Zhishi Quo and Nancy Roache are-with Acurex Environmental Corp., Research
    Triangle Park, NC 27709.
  Mark A. Mason is the EPA Project Officer (see below).              t^mnloa
  The complete report, entitled "Characterization of E™ss™s*ro™C
    Using a 10-Gallon Aquarium as the Source Chamber," (Order No.
    Cost: $27.00, 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:
         Air and Energy Engineering Research Laboratory
         U.S. Environmental Protection Agency
         Research Triangle Park, NC 27711	
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use $300

EPA/600/SR-94/141
     BULK RATE
POSTAGE & FEES PAID
         EPA
   PERMIT NO. G-35

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