United States
Environmental Protection
Agency
Effects of Vapor-Based
Decontamination Systems
on Selected Building Interior
Materials: Chlorine Dioxide
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EPA/600/R-08/054 April 2008 www.epa.gov/ord
Effects of Vapor-Based Decontamination
Systems on Selected Building Interior
Materials: Chlorine Dioxide
Mark D. Brickhouse
Teri Lalain
Philip W. Bartram
Monicia Hall
Zoe Hess
Brent Mantooth
Louis Reiff
EDGEWOOD CHEMICAL AND BIOLOGICAL CENTER
RESEARCH AND TECHNOLOGY DIRECTORATE
Zach Zander
David Stark
Pamela Humphreys
SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
Abingdon,MD21009
Shawn Ryan
Blair Martin
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, NC 27711
Office of Research and Development
National Homeland Security Research Center, Decontamination and Consequence Management Division
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Disclaimer
EPA through its Office of Research and Development The report has been subject to an administrative
partially funded and collaborated in the research described review but does not necessarily reflect the views of the
herein under Interagency Agreement (IAG) DW 939917-01- Agency. No official endorsement should be inferred. EPA
0 with the U.S. Army Edgewood Chemical and Biological does not endorse the purchase or sale of any commercial
Center (ECBC). The work performed in association with this products or services.
report was conducted from November 2003 to October 2006.
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Acknowledgments
A program cannot be successfully completed without the The authors thank Dr. David Cullinan (SAIC/Geo-Centers,
contributions of a good team of people. The authors thank the Inc.) for preparing many coupon run baskets, coupon
following individuals for their hard work and assistance with measurements, and chain-of-custody forms during the time
the execution of this technical program. his assigned laboratory was closed.
The authors thank Mr. David Sorrick (ECBC) for his
assistance in acquiring the test equipment and the design and
construction of the circuit breaker test stations.
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Table of Contents
1. BACKGROUND 1
2. SUMMARY OF CONCLUSIONS 2
3. INTRODUCTION 3
4. EXPERIMENTAL Method 4
4.1 Coupon Preparation 4
4.2 Coupon Exposure: Wood, Wallboard, Ceiling Tile, Steel, Carpet, and Concrete Cinder Block 4
4.3 Coupon Exposure: Circuit Breakers 4
4.4 Visual Inspection 4
4.5 Coupon Aging 6
4.6 Data Review and Technical Systems Audits 6
4.7 Physical Testing 6
4.8 Statistical Analyses 6
4.9 Chemical Testing: Ion Chromatography 6
5. POST-FUMIGATION INSPECTION RESULTS 7
6. EVALUATION OF STRUCTURAL STEEL 8
6.1 Introduction 8
6.2 Sample Preparation and Testing 8
6.3 Results 9
6.4 Discussion 9
7. EVALUATION OF GYPSUM WALLBOARD 11
7.1 Introduction 11
7.2 Sample Preparation and Testing 11
7.3 Results 12
7.4 Discussion 12
8. EVALUATION OF ACOUSTICAL CEILING TILE 13
8.1 Introduction 13
8.2 Sample Preparation and Testing 13
8.3 Results 14
8.4 Discussion 16
9. EVALUATION OF CARPET 17
9.1 Introduction 17
9.2 Sample Preparation 17
9.3 Results 17
9.4 Discussion 19
10. EVALUATION OF CONCRETE CINDER BLOCK 20
10.1 Introduction 20
10.2 Sample Preparation and Testing 20
10.3 Results 21
10.4 Discussion 22
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Table of Contents
11. EVALUATION OF WOOD 23
11.1 Introduction 23
11.2 Sample Preparation 23
11.3 Results 23
11.4 Discussion 25
12. EVALUATION OF ELECTRICAL CIRCUIT BREAKERS 26
12.1 Introduction 26
12.2 Sample Preparation 26
12.3 Circuit Breaker Testing Stations 26
12.4 Results 27
13. CHLORINE DIOXIDE FATE ON METALS 29
13.1 Introduction 29
13.2 lest Procedure 29
13.3 Sample Analysis 29
13.4 Results 29
14. QUALITY ASSURANCE FINDINGS 31
LITERATURE CITED 32
Appendix A: Coupon Identifier Code 33
Appendix B: Detailed Coupon Preparation and Inspection Procedures 35
Appendix C: Wood Coupon Location of Break 37
Appendix D: Concrete Cinder Block Coupon Location of Break 40
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Figures
4.1 Samples of the Test Coupons 5
6.1 Steel Coupon lest 8
7.1 Gypsum Wallboard Coupon Test 11
8.1 Acoustical Ceiling Tile Coupon Test 13
8.2 Representative Break - Acoustical Ceiling Tile Coupons 14
9.1 Carpet Coupon Test 17
10.1 Concrete "Cinder Block" Coupon Test 20
10.2 Representative Concrete Coupon Before and After Testing 21
11.1 Wood Coupon Test 23
11.2 Representative Wood Coupon Before and After Testing 23
12.1 Circuit Breaker Test Station Photograph 26
13.1 Copper Tubing Prior to Exposure to Chlorine Dioxide 30
13.2 Copper Tubing After Exposure to Chlorine Dioxide 30
Tables
4.1 Representative Building Interior Materials 5
4.2 Instron Model 5582 Specifications 6
6.1 CD Steel Coupon Test Results 10
7.1 Gypsum Wallboard Coupon Test Results for Maximum Load 12
8.1 CD Coupon Test Results for Tile 15
9.1 Carpet Coupon Test Results for Average Tuft Bind - CD Control Samples 18
10.1 CD Coupon Test Results for Concrete Cinder Block 22
11.1 CD Coupon Test Results for Wood 24
12.1 Chlorine Dioxide Circuit Breaker Test Results 27
12.2 Summary of Time-to-Open Data 28
13.1 Residual Anions on Metal Coupons after Exposure to Chlorine Dioxide 30
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List of Acronyms
APG Aberdeen Proving Grounds
ASTM American Society for Testing and Materials
CB chemical and biological
CD chlorine dioxide
CoC chain-of-custody
CT concentration time
CW chemical warfare
doc documentation
DS Decontamination Sciences
ECBC Edgewood Chemical and Biological Center
EPA U.S. Environmental Protection Agency
GSA General Services Administration
H2O2 hydrogen peroxide
hr or hrs hour or hours
IAG Interagency Agreement
IAW in accordance with
ID Gant chart representation for task number (on Gant Chart only)
IOP Internal Operating Procedure
ISO 17025 International Standardization Organization Standard 17025 on Laboratory Quality Procedures
MSDS Material Safety Data Sheets
N Newton
NHSRC National Homeland Security Research Center
QA quality assurance
QAPP Quality Assurance Project Plan (QAPP)
QMP Quality Management Plan
R&D Research and Development
RDECOM Research, Development, and Engineering Command (formerly SBCCOM)
RH relative humidity
SOPs standing operating procedures ("standard" may also be used in place of "standing" with the same meaning)
TICs toxic industrial chemicals
TIMs toxic industrial materials
UL Underwriters Laboratories
VHP®, VHP reference to Steris' registered "vaporized hydrogen peroxide" procedure
COUPON SPECIFIC CODING
"W" bare wood
"R" carpet
"T" ceiling suspension tile
"G" latex-painted gypsum wallboard
"S" painted structural A572 steel
"C" unpainted concrete cinder block
"A" aluminum coupons
"D" copper coupons
"F" steel coupons
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Background
The material compatibility studies were designed to
determine how decontaminant vapors impact building
materials within an enclosed building interior space. Since
building interiors contain large surfaces composed of
complex material and electrical components such as circuit
breakers, data are needed to determine how such materials
are affected by exposure to the vapor. Vaporized hydrogen
peroxide (VHP®) and chlorine dioxide (CD) were selected
since these decontamination technologies have been used
to decontaminate indoor surfaces contaminated by anthrax
and/or show potential for use in decontaminating indoor
surfaces contaminated by chemical agents. The representative
building interior materials tested were unpainted concrete
cinder block, standard stud lumber (2" x 4" fir), latex-painted
'/2-inch gypsum wallboard, ceiling suspension tile, painted
structural steel, and carpet. The physical properties of the
building materials were measured using ASTM test methods.
The material compatibility studies also investigated electrical
breakers, using Underwriters Laboratories (UL) test methods
and the breaker components aluminum, copper, and steel.
The samples were studied using specialized chemical testing
to determine the type of chlorine containing salts on the metal
surface. In addition, visual appearance was documented.
This report contains the results for the CD-exposed coupon
material compatibility tests. The VHP results are documented
in a separate report.
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Summary of Conclusions
CD-exposed building materials showed some minor changes
in integrity but no change in appearance compared to
nonexposed samples. The samples were evaluated for outliers
using the Dixon's Q-Test in accordance with (IAW) ASTM
Method E 178 and for statistically demonstrated differences
using the Welch's T-Test.
• Visual Inspection: No differences were observed for
any of the six main material type coupons after CD
exposure and aging compared to before CD exposure.
• Painted Structural Steel: The CD-fumigated structural
steel coupons showed no change in the maximum load
required to break the samples compared to the controls.
Minor differences in tensile strength were reported;
however, these differences were due to differences in
the cross-section area of the coupons that were within
the tolerance limits set for quality control. All samples
were above the specified tensile strength requirements
of the ASTM test (by 20% or more). There is no
obvious change in the potential for failure of the steel
after fumigation using CD.
• Gypsum Wallboard: No statistically significant
difference in the resistance to penetration by a nail
was observed between the control and CD-fumigated
coupons. The differences noted were well within both
the 15% variation indicated in the ASTM specification
and the standard deviations of the test.
• Ceiling Tile: Exposure to CD has no statistically
significant effect on the force required to break the
ceiling tile coupons compared to the controls.
• Carpet: There appears to be a minor increase for the
average tuft bind results with exposure to CD, but the
difference is smaller than the standard deviations of the
individual test results.
Concrete Cinder Block: The fumigated concrete
cinder blocks did not exhibit any changes from the
control samples. There is no evidence to indicate that
fumigation with CD has any effect on the cinder blocks.
Wood: Exposure to high concentrations of CD for short
durations appears to reduce the tensile strength of the
furring strips prepared from the standard stud lumber,
causing them to fail more rapidly (2% decrease at
half-target, 15% decrease at target concentration) and
at lower applied forces (+1.4% at half-target, -17% at
target concentration).
Circuit Breakers: Exposure to CD presented a
conflicting picture of the effects on circuit breakers.
Under the 60-amp challenge (300% of the rated value),
exposed circuit breakers showed no statistically
significant difference compared to the controls
with respect to the time to trip. Under the 30-amp
challenge, the circuit breakers tripped more slowly
than the controls. Failure criteria must be established to
determine whether this is an acceptable response.
Residual Analysis on Metals: Chlorine dioxide
decomposed on aluminum to yield chloride, chlorite,
chlorate, and perchlorate anions. The products from
the reaction of chlorine dioxide with copper and steel
surfaces were chloride, chlorate, and perchlorate.
The reaction of chlorine dioxide on steel was the
most severe, with chloride the most abundant product.
The metal chloride, a decomposition product of the
other anions, was the most abundant species on each
metal. The number of chloride anions on each metal
was similar in the 6-hr (1000 ppm) and 12-hr (2000
ppm) tests.
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Introduction
To address homeland security needs for decontamination,
the U.S. Environmental Protection Agency (EPA) established
an Interagency Agreement with the U.S. Army Edgewood
Chemical and Biological Center (ECBC) to take advantage
of ECBC's extensive expertise and specialized research
facilities for the decontamination of surfaces contaminated
with chemical and biological (CB) warfare agents. The
National Homeland Security Research Center (NHSRC)
formed a collaboration with ECBC in a mutual leveraging of
resources, expanding upon ECBC's ongoing programs in CB
decontamination to more completely address the parameters
of particular concern for decontamination of indoor surfaces
in buildings following a terrorist attack using CB agents,
or toxic industrial chemicals (TICs) or materials (TIMs). In
the context of decontamination, the contaminants of interest
are those that can persist on indoor surfaces, leading to
continuing chance of exposure long after the contamination
occurs. VHP® and CD are decontamination technologies
that have been used to decontaminate indoor surfaces
contaminated with anthrax spores and that show potential
for use in decontaminating indoor surfaces contaminated
by some chemical agents. This program is specifically
focused on decontamination of the building environment,
for purposes of restoring a public building to a usable
state after a terrorist contamination episode. Systematic
testing of decontamination technologies generates objective
performance data so building and facility managers, first
responders, groups responsible for building decontamination,
and other technology buyers and users can make informed
purchase and application decisions.
Since building interiors may contain large surfaces composed
of complex materials, the material compatibility studies were
designed to determine how decontaminant vapors impact
building materials within an enclosed building interior space.
The objective of this study was to establish and conduct
laboratory test procedures to determine to what degree
interior building materials were affected by decontamination
using VHP® and CD. The building materials used for testing
were a subset of the variety of structural, decorative, and
functional materials common to commercial office buildings,
regardless of architectural style and age. The building
materials encompassed a variety of material compositions
and porosities; the materials studied included unpainted
concrete cinder block, standard stud lumber (2" x 4" fir,
type-II), latex-painted '/2-inch gypsum wallboard, acoustical
ceiling suspension tile, primer-painted structural steel, and
carpet. The material compatibility studies also investigated
material(s) related to electrical breaker connections. The
physical appearance was documented by visual inspection of
the test material, and the physical properties of the building
materials were measured using standardized ASTM and
Underwriters Laboratories (UL) test methods. Specialized
chemical testing was conducted to determine whether
chemical changes occurred in select building materials.
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Experimental Method
The material compatibility testing was conducted in
compliance with the Quality Assurance Project and Work
Plan1 developed under the Quality Management Plans2'3 and
EPA E4 quality system requirements.4"7
4.1 Coupon Preparation
Test coupons were prepared in accordance with the ASTM
testing requirements for material compatibility testing. The
coupons were cut from stock material in accordance with
(IAW) the procedure in Appendix B of the QAPP8, which
has been reproduced as Appendix B of this report. Coupons
were prepared by obtaining a large enough quantity of
material that multiple test samples could be obtained with
uniform characteristics (e.g., test coupons were all cut from
the interior rather than the edge of a large piece of material).
The building materials studied, including supplier and
coupon dimensions, are provided in Table 4.1 and shown
in Figure 4.1., see page 5.
Chain-of-custody (CoC) cards were used to ensure that the
test coupons were traceable throughout all phases of testing.
The test coupons were measured and visually inspected prior
to testing. Coupons were measured to ensure that the test
coupon was within the acceptable tolerances (Appendix B).
Coupons were visually inspected for defects and/or damage.
Coupon measurements and visual inspection were recorded
on the CoC card. Coupons that were defective, damaged, or
not within the allowable size tolerances were discarded. Each
coupon was assigned a unique identifier code that matched
the coupon with the sample, test parameters, and sampling
scheme (Appendix A). The code was recorded on the CoC
form. The CoC cards followed each sample from exposure
testing through material compatibility testing to disposal.
The material compatibility studies also investigated materi-
als related to electrical breaker connections such as intact
circuit breakers and component metals aluminum, copper,
and steel. The circuit breakers were one-pole circuit breakers
(HOM120, 2400 watts, 120/240 volts, 20 amperes).
4.2 Coupon Exposure: Wood, Wai I board, Ceiling Tile,
Steel, Carpet, and Concrete Cinder Block
The process for exposing the building material samples to CD
and results for the material demand study are documented in
a separate report titled "Material Demand Studies: Materials
Sorption of Chlorine Dioxide," by Phil Bartram et. al. This
testing followed the operating procedures discussed with
the sponsor and is not specific to any particular vendor. A
brief overview of the exposure process is provided in this
section. The material demand report contains the detailed test
information and results.
The coupons were placed in the exposure chamber,
which had been conditioned to achieve the target relative
humidity (RH) of 75% and target temperature of 75 °F.
The vapor generator was operated to maintain the
chamber concentration within specified ranges. The target
concentration was 2000-ppm CD for six hours for a total
concentration-time (CT) value of 12,000 ppm-hrs. The half-
target concentration was 1000-ppm CD for twelve hours also
for a total concentration-time (CT) value of 12,000 ppm-
hrs. The CD tests were conducted with a turnover rate of
approximately one air exchange per hour due to the relative
stability of CD and to mimic actual treatment conditions.
Aeration of the chamber was conducted following the
decontamination phase (exposure period) and continued
until the vapor concentration fell to/below the levels required
by the Risk Reduction Office to ensure safe operation for
personnel. The coupons remained in the chamber until
aeration was complete. Control samples were prepared using
the same procedure as the test runs except with only air (no
fumigant) through the chamber. Three replicate runs were
done for each sample at each condition. The samples were
removed from the chamber, marked with unique sample
identifier codes, and visually examined.
4.3 Coupon Exposure: Circuit Breakers
Like the other building materials discussed in Section 4.2,
the circuit breakers (Hom220, Home Depot) were placed
in the exposure chamber and exposed to fumigant. After
exposure to the decontaminant, the circuit breakers were
stored in a fume hood for two days and then placed in storage
under load for three months. Each set of circuit breakers was
inserted into an electrical box (8 spaces, 16 circuits, 100 amp
max from square D, Home Depot # 577-340). The circuit
breaker box was wired with 12-gauge, 20-amp wire into
the 120-V outlet. Each circuit breaker was wired in series
with an electrical lamp (s513e) with an outlet box (sllOe)
manufactured by Thomas & Bretts (Home Depot # c214477
and b214426, respectively). The load in each lamp was a
Phillips 40-watt light bulb (Philips and Sylvania, Home
Depot). Current was applied to the circuits and monitored.
At the end of 90 days, the circuit breakers were tested to
determine the effect of CD fumigation.
4.4 Visual Inspection
The coupons were visually inspected and digitally
photographed upon removal from the chamber. Visual
inspection of the coupon surfaces was conducted through
side-by-side comparison of the decontaminated test surface
and fresh coupons of the same test material. The testing
staff looked for changes such as discoloration, blistering,
warping, and peeling on the test coupons compared to the
fresh coupons. After the visual inspection was completed, the
coupon custody was transferred to the Material Compatibility
Technical Leader for the three-month aging period and
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Table 4.1: Representative Building Interior Materials
Structural Wood, fir
Latex-Painted Gypsum Wallboard
Concrete Cinder Block
Carpet
Painted Structural Steel
Ceiling Suspension Tile, Acoustical
W
G
C
R
S
T
Home Depot
Home Depot
York Supply
Home Depot
Specialized Metals
Home Depot
10.0 in
6.0 in
4.0 in
6.0 in
12.0 in
5.3 in
12.0 in
1.5 in
6.0 in
8.0 in
8.0 in
2.0 in
0.8 in
3.0 in
0.5 in
0.5 in
1.5 in
0.0 in
0.3 in
0.3 in
0.6 in
Figure 4.1: Samples of the Test Coupons*
Coupons are not shown to scale
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material compatibility testing. The coupons were examined
again at the time of the material testing and the visual
appearance recorded on the data test forms. If the coupon
showed dramatic changes compared to a fresh coupon, then
the coupon was photographed and the photograph included in
the report. Representative photographs of each material type
are provided in the report.
4.5 Coupon Aging
The material compatibility studies were conducted using
the coupons from the material demand study. The coupons
were aged for a minimum of 90 days following exposure to
the decontaminant prior to material compatibility testing.
The coupons were placed in open containers and stored
under ambient conditions. The open container arrangement
allowed aging of the coupons in conditions mimicking real-
world aging.
4.6 Data Review and Technical Systems Audits
The approved Material Compatibility QAPP specified
procedures for the review of data and independent technical
system audits. All data were peer reviewed within two weeks
of collection. The project quality manager (or designee)
was required to audit at least 10% of the data collected.
The project quality manager (or designee) performed
three technical system audits over the course of testing. A
technical system audit is a thorough, systematic, on-site,
qualitative audit of the facilities, equipment, personnel,
training, procedures, record keeping, data validation, data
management, and reporting aspects of the system.
4.7 Physical Testing
An Instron model 5582 was used for the physical property
testing. The Instron is a universal testing machine capable
of performing tensile, compression, shear, peel, and flexural
tests on most materials and components. Each material
subsection contains a photograph of the coupon loaded into
the test apparatus. The Instron model 5582 specifications are
listed in Table 4.2.
Table 4.2: Instron Model 5582 Specifications
Load Capacity:
Maximum Speed:
Minimum Speed:
Maximum Force at Full Speed:
Maximum Speed at Full Load:
Return Speed:
Position Control Resolution:
Total Crosshead Travel:
Total Vertical Test Space:
Height:
Width:
Depth:
Weight:
kN
Kgf
mm/min
mm/min
kN
mm/min
mm/min
ixm
mm
mm
mm
mm
mm
kg
100
10000
500
0.001
75
250
600
0.06
1235
1309
2092
1300
756
862
4.8 Statistical Analyses
The data from the material compatibility testing phase of
the systematic decontamination program was subjected to
a statistical analysis to determine whether the differences
observed among the various test sets were merely the result
of random variations in test data or represented actual
differences in the performance of the materials as a result of
exposure to fumigation chemicals.
Methods used were from the statistical analysis functions
embedded within both the Microsoft Excel software and
Practical Statistics for Analytical Chemists, by Robert L.
Anderson, © 1987, Van Nostrand Reinhold Company.
First, the individual coupon sets were tested for statistical
outliers that could be eliminated from the data. The Q-Test
for outliers was first used to identify potential outliers within
a test set. Then the test group of coupons that had undergone
similar treatment (controls, half-target, or full-target
exposures) was tested. If an outlier identified in the individual
coupons was also picked out in the test group analysis, it
was eliminated and the statistics (averages and standard
deviations) recalculated. However, if the specific data point
was not identified as an outlier by both tests, it was retained
in the study. Once statistical outliers had been eliminated, the
test groups were analyzed to determine whether they were
statistically significantly different — that is, to determine
whether the treatment with the chosen fumigant had a
detectable effect on the sample.
The primary test used was the Welch's T-test; the two-tailed,
heteroscedastic test was used for the analysis. Welch's T-test
values were calculated to compare the test groups, and results
are reported for the 95% level of confidence. The percent
level of confidence reported indicates the confidence that the
two sample groups being compared are, in fact, different, and
represent truly different samples. A 95% level of confidence
indicates that there is a 5% chance that the two samples are,
in fact, subparts of the same population. If a comparison
determines that a sample is significantly different at the X%
level of confidence, it is also significantly different at any
lower level of confidence.
Determination that a control and exposed sample are
statistically different implies that the treatment had some
detectable effect on the material. Statistically different
results do not imply that the material will fail as a result of
treatment, unless the material no longer meets specifications.
In some cases measured values may vary by several percent;
however, there is no statistically detectable difference. It
cannot be assumed that this difference is real unless the
difference is statistically detected (e.g., by a Welch's T-test).
4.9 Chemical Testing: Ion Chromatography
The program also included additional CD tests of metals
commonly used in electrical applications. Metal samples
were exposed to CD and analyzed for the presence of
chloride, chlorite, chlorate, and perchlorate anions in aqueous
CD decontamination matrices using ion chromatograph (1C)
with conductivity detection. The results of this study are
discussed in Section 13 of this report.
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Post-Fumigation Inspection Results
The coupons were visually inspected prior to fumigation,
immediately after fumigation (post-fumigaiton), and after
storage (post-storage) at time of material testing. Carpet
coupons were inspected for any frayed tufts, pulled loops,
and other noticeable defects. Concrete coupons were
inspected for cracks, chips — particularly at the corners —
any raised ridge sections, and other noticeable defects. Steel
coupons were inspected for rust, peeling paint, any ridged
sections on the small I-beam cross section, and any other
noticeable defects. Tile coupons were inspected for crushed
corners and edges, and any other noticeable defect. Wallboard
coupons were inspected for any damage to the paper section,
as well as any other noticeable defects. Wood coupons were
inspected for any knots, missing knots, splitting, and other
noticeable defects. The post-fumigation and post-storage
inspections were compared to the initial inspections. No
differences were observed for any of the coupons after CD
exposure and aging compared to before CD exposure.
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Evaluation of Structural Steel
6.1 Introduction
The effects of CD on the physical integrity of steel were
investigated using the tension test as described in ASTM test
method A370-03a "Standard Test Methods and Definitions
for Mechanical Testing of Steel Products," Sections 5 to 13.
The tension test was used to determine the integrity of steel
coupons exposed to vaporous decontaminant compared to
unexposed (control) steel coupons.
6.2 Sample Preparation and Testing
The steel coupons were removed from storage, visually
inspected, and measured to confirm that they were within
coupon specifications listed in Appendix A. The coupons
from chamber positions 1, 4, 7, 10, and 16 were selected
for testing in order to obtain representation throughout
the test chamber. The coupons were used "as is" without
any additional preparation. The testing was conducted
in accordance with ASTM Test Method A370-03a. The
Figure 6.1: Steel Coupon Set
Instron fixture for the steel test was installed into the Instron
universal testing machine prior to testing. The testing
machine operation and calibration verification was conducted
by suspending a certified weight from the fixture and
recording the weight. Three sets of five coupons were tested
for each concentration (full-target and half-target) and four
sets were tested for the controls (0 ppm). The load required
to rupture the steel coupons was measured in Newtons
(N). The tensile strength is the maximum tensile stress
that a material is capable of sustaining and is calculated by
dividing the amount offeree required to rupture a specimen
by the specimen cross-sectional area. No precision or bias
requirements have been established for this test method.
The results for control coupons were compared against the
results for decontaminant-exposed samples. A statistical
analysis of the data was conducted to determine whether the
decontaminant-exposed steel coupon results were statistically
different compared to the control steel coupons results.
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6.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based
on the arrival of the Instron fixture for testing. The coupons
for a particular fumigation trial were studied after a similar
number of days in storage. A photograph of a representative
steel sample before and after testing is provided in Figure
6.1. Values for the load required to rupture the steel coupons,
the tensile strength results, and the number of days in storage
before testing are provided in Table 6.1.
6.4 Discussion
The steel studied was an A572 Grade 50 high-strength,
structural steel. The minimum tensile strength requirement
is 450 N/mm2. Both the control coupons and CD-exposed
coupons met this minimum specification.
Of the 50 coupons tested in this portion of the program, only
one generated a result that could be rejected as a statistical
outlier from within its individual test set at the Q=0.99 level
of confidence: Coupon 5 from test set SN50302, which
had a tensile strength value significantly below the others
in its test set. Within test groups (control samples, half-
target concentration samples, and full-target concentration
samples), similar statistical analysis showed that none of
the coupon sets could be eliminated as statistical outliers.
Therefore, Coupon 5 was retained for this analysis.
The values for the maximum load for the steel coupons were
determined to be 61136 ± 1347 N for the control samples,
62308 ± 1560 N for the half-target samples, and 62639 ±
1538 N for the full-target coupons. The value for the tensile
strength of the steel coupon is the maximum load (Newton)
divided by the cross-sectional area (mm2) of the coupon at
the break point. The values for the tensile strength of the
steel coupons were calculated to be 553 ± 14 N/mm2 for the
control coupons, 545 ± 24 N/mm2 for the half-target coupons,
and 554 ± 20 N/mm2 for the full-target coupons.
With regard to the data from the test group of coupons, the
average maximum load values for the CD-exposed coupons
differed by less than 3% from the control samples, and the
tensile strengths varied by about 1%. The Welch's T-test
was used to determine whether any of the groups of samples
were statistically different from the others. The tensile
strength results showed no statistical difference between the
controls, half-, or full-target concentration samples at the
95% confidence level. The average maximum load values for
the half-target or full-target coupon samples, however, were
statistically different from the control samples at the 95%
confidence level. This is a result of slight differences in the
cross-sectional areas between the groups that were still within
the target tolerance values for quality control and not due to
an effect of the fumigation process.
-------
Table 6.1: CD Steel Coupon Test Results
Maximum
Coupon set
on Test Resu
SN50302
SSN51018
SSN50525
SN50228
-Target Concent
00-1250 ppm) Result:
SSD50928
SSD51004
SSD51005
SSD50919
SSD50921
SSD50927
Coupon 1
60616
60025
61501
61175
62076
63593
62285
60049
63305
64290
Coupon 2
60916
58303
61041
61559
63920
63181
64543
64989
62608
63527
Coupon 3
61191
63318
62511
60806
61906
58890
63163
60248
62549
59927
Coupon 4
60890
59384
60302
60731
61904
62222
59911
62529
63792
63872
Coupon 5
61049
64803
61698
60900
64228
61673
61122
61831
63135
62932
Test Average
60932
61167
61410
61034
62807
61912
62205
61929
63078
62909
Standard Deviation
214
2763
817
338
1164
1852
1791
2006
516
1740
Test Set Average ±
Standard Deviation
61136 ± 1347
62308 ± 1560
Tensile Str
ontrol Samples (0 ppm!
ensile Strength, N/mm2
alf-Target Concentratioi
(1000-1250 ppm)
62639 ± 1538
Target Concentration
'000-2500 ppm)
ICUllllllfl
Coupon set
SN50302
SSN51018
SSN50525
SN50228
SSD50928
SSD51004
SSD51005
SSD50919
SSD50921
SSD50927
Coupon 1
561
527
569
537
575
558
546
556
586
536
Coupon 2
564
540
535
570
561
554
538
570
522
529
Coupon 3
567
555
548
563
573
545
475
558
579
526
Coupon 4
564
550
558
562
543
546
526
579
560
560
Coupon 5
536
540
571
534
563
541
536
542
554
552
Test Average
558
542
557
553
563
549
524
561
560
541
Standard Deviation
13
11
15
17
13
29
14
25
15
Test Set Average ±
Standard Deviation
553 ± 14
545 ± 24
554 ± 20
i in miti} i ii 11
TO tutu 111 r. 11 in I • *KVl
in Storage
Coupon set
SN50302
SSN51018
SSN50525
SN52228
SSD50928
SSD51004
SSD51005
SSD50919
SSD50921
SSD50927
Coupon 1
103
159
96
98
173
168
167
220
218
181
Coupon 2
103
159
96
98
173
168
167
220
218
181
Coupon 3
103
159
96
98
173
168
167
220
218
181
Coupon 4
103
159
96
98
173
168
167
220
218
181
Coupon 5
103
159
96
98
173
168
167
220
218
181
Test Set Average ±
Standard Deviation
114 ± 27
169 ± 3
206 ± 19
Note: The cell highlighted in yellow indicates that the data point was statistically identified as an outlier within its test set but not within the test
group (four control groups); therefore, the value was retained.
-------
Evaluation of Gypsum Wallboard
7.1 Introduction
The effects of CD fumigation on the physical integrity of
gypsum wallboard were investigated using the nail pull-
through resistance test method B as described in ASTM
Test Method C473-03 "Standard Test Methods for Physical
Testing of Gypsum Panel Products," Section 13. The test
measures the ability of the wallboard to resist nail pull-
through by determining the load required to push a standard
nail through the wallboard. The ASTM test was used to
determine the integrity of the gypsum wallboard coupons
exposed to vaporous decontaminant compared to unexposed
(control) gypsum wallboard coupons.
7.2 Sample Preparation and Testing
The gypsum wallboard coupons were removed from storage,
visually inspected, and measured. The coupons from chamber
positions 1, 2, 4, 5, and 7 were selected for testing in order
to obtain representation throughout the test chamber. The
samples were brought to moisture equilibrium such that the
weight of the sample did not change by more than 0.2% on
successive weighings at a minimum interval of two hours.
Figure 7.1: Gypsum Wallboard Coupon Test
The sample preparation was conducted within a range of
15-25 °C and 48-75% RH. The testing was conducted in
accordance with ASTM Test Method C473-03. The Instron
fixture for the gypsum wallboard test was installed prior to
testing. The Instron universal testing machine operation was
verified by suspending a certified weight from the fixture
and recording the weight. Three sets of five coupons were
tested for each concentration (full-target and half-target)
and four sets were tested for the controls (0 ppm). The force
required to drive a nail shank through the wallboard coupons
was measured in N. The ASTM method indicates that any
coupon measurement in the series that varies 15% more than
the average needs to be discarded. The method states that if
15% of the coupons deviate from the average, the test will
be repeated. No additional precision or bias requirements
have been determined for this test by ASTM. The results
for control coupons were compared against the results for
decontaminant-exposed coupons. A statistical analysis of the
data was conducted to determine whether the decontaminant-
exposed coupon results were statistically different from the
control coupon results.
-------
7.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based on
the arrival of the Instron fixture for testing. The coupons for a
particular fumigant were studied at the same number of days.
A photograph of a gypsum wallboard sample before and after
testing (i.e., holes) is provided in Figure 7.1. Values for the
load required to push the nail through the wallboard coupons
and number of days in storage before testing are provided in
Table 7.1.
Table 7.1: Gypsum Wallboard Coupon Test Results for Maximum Load
Coupon set
Hole 1
Hole 2
Hole 3
Hole 4
Hole 5
Test Average
Standard Deviation
Test Set Average ±
Standard Deviation
Days in Storage
GN50316
64.2
62.3
60.8
71.0
61.0
63.8
4.2
GN50301
55.1
44.1
48.8
54.3
45.8
49.6
5.0
GN50518
43.4
37.3
37.0
38.3
43.8
39.9
3.4
GN50512
45.3
41.6
47.2
52.0
51.2
47.5
4.3
50.2 ± 9.7
175
190
349
355
B Concentration Half-Target Concentration
)0 ppm) Results, N (1000-1250 ppm) Results, N
GD50417
57.1
69.4
72.1
56.4
67.4
64.5
7.3
GD60412
40.2
49.6
43.9
47.8
41.0
44.5
4.1
GD60413
67.88
65.32
70.30
69.5
73.48
69.3
3.0
59. 4 ± 12.1
157
161
163
GD60418
61.29
52.19
65.02
55.19
58.36
58.4
5.0
GD60420
56.33
47.72
62.27
55.18
57.50
55.8
5.3
GD602424
47.96
50.49
63.78
57.92
59.45
55.92
6.5
56.7 ± 5.4
157
155
151
7.4 Discussion
The wallboard tension test results were analyzed for potential
statistical outliers using the Q-test and for differences
between the control and exposed samples using Welch's T-
test. Although there was a great deal of scatter in the data (the
data ranged from 37.0 to 73.5 N, the standard deviations of
the results were between 9 and 21% of the mean value within
the various test groups); therefore, none of the individual
coupons were determined to be outliers at the Q=0.99
confidence level.
The average tension test results were 50.2 ± 9.7 N for the
control group, 56.7 ± 5.4 N for the half-target group, and
59.4 ± 12.1 N for the full-target group. The differences
were not determined to be statistically significant at the
95% confidence interval as determined by the Welch's
T-test. Therefore, it did not appear that exposure to the CD
fumigation process impacted the wallboard with respect to
the ASTM tension test used for analysis.
-------
8
Evaluation of Acoustical Ceiling Tile
8.1 Introduction
The effects of CD on the physical integrity of ceiling
tile were investigated using the transverse strength test
as described in ASTM Test Method C367-99 "Standard
Test Methods for Strength Properties of Prefabricated
Architectural Acoustical Tile or Lay-In Ceiling Panels"
Sections 1, 3-5, and 21-29. The test measures the force
required to cause the tile to break. The ASTM test was used
to determine the integrity of ceiling tile coupons exposed to
vaporous decontaminant compared to unexposed (control)
ceiling tile coupons.
8.2 Sample Preparation and Testing
The acoustical ceiling tile samples were removed from
storage, visually inspected, and measured. The samples were
brought to moisture equilibrium such that the weight of
the sample did not change by more than 1% on successive
weighings at a minimum interval of two hours. The sample
preparation was conducted within a range of 18-24 °C and
48-75% RH. The testing was conducted in accordance
with ASTM Test Method C367-99. The Instron fixture
for the ceiling tile test was installed prior to testing. The
Instron universal testing machine operation was verified by
suspending a certified weight from the fixture and recording
the weight. For each test, the coupons from chamber
positions 1 through 8 were selected for testing; this selection
consisted of all coupons placed in the chamber during a
single fumigation trial. Ceiling tile coupons were tested in
two directions — with the mandrel parallel to the axis of the
Figure 8.1: Acoustical Ceiling Tile Coupon Test
test machine (hereafter referred to as "machine direction")
and with the mandrel perpendicular to the axis ("cross-
machine direction"). Three sets of four machine-direction
coupons and four cross-machine-direction coupons were
tested for each concentration (full-target and half-target)
and four sets were tested for the controls (0 ppm) for each
direction. The load required to break the ceiling tile coupons
was measured in N. Figure 8.1 shows a photograph of a
coupon loaded into the Instron for the machine and cross-
machine direction tests. No precision or bias requirements
have been established for this test method. The results of
control coupons have been compared to the results for
decontaminant-exposed tiles. A statistical analysis of the data
was conducted to determine whether the decontaminant-
exposed coupon results were statistically different from the
control coupon results.
The Modulus of Rupture (MOR) was calculated according to
the test method using the following equation:
MOR units N/mm2 (lbf/in2) =
3xPxL
2xbxd2
where P is the maximum load, N (Ibf)
L is the length of span, mm (in.)
b is the specimen width, mm (in.)
d is the specimen thickness, mm (in.)
Cross-Machine Direction
In-Machine Direction
-------
8.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based on
the arrival of the Instron fixture for testing. The coupons for
a particular fumigation trial were studied at the same number
of days. A photograph of a representative ceiling tile sample
before and after testing is provided in Figure 8.2. Values for
the load required to break the ceiling tile coupons, the ceiling
tile coupon MOR results, and number of days in storage are
provided Table 8.1.
Figure 8.2: Representative Break - Acoustical Ceiling Tile Coupons
In-Machine Direction
Cross-Machine Direction
-------
Table 8.1: CD Coupon Test Results for Tile
on Test Resu
lalf-Target Concentrati
00-1250 ppm) Result1
Target Concentratio
00-2500 ppm) Results, N
Coupon set
TN51024
TN50223
TN50517
TN50519
TD60301
TD60329
TD60328
TD60228
TD60223
TD60227
Coupon 1
37.10
31.27
51.49
38.82
44.48
42.80
41.17
34.31
40.08
32.58
Coupon 2
39.63
29.80
32.19
43.15
41.09
42.80
41.13
41.68
35.96
32.87
Coupon 3
33.44
30.82
36.85
41.70
34.79
36.71
37.14
36.69
36.75
33.19
Coupon 4
36.73
34.54
40.48
42.76
31.88
43.76
41.01
38.21.
40.03
29.99
Coupon 5
31.19
Test Average
36.73
31.52
40.25
41.61.
38.06
41.52.
40.11
37.72
38.21
32.16
Standard Deviation
2.54
1.78
1.96
5.75
3.24
l.S
3.09
2.16
1.47
Test Set Average ±
Standard Deviation
37.17 ± 5.72
39.90 ± 3.89
36.03 ± 3.56
ontrol Samples (0 ppm)
Target Concent
000-1250 ppm)
Results, N/mm2
Test 2
et Concentrati
00-2500 ppm)
Results, N/mm2
Test 2 Test 3
Coupon set
TN51024
TN50223
TN50517
TD50519
TD60301
TD60329
TD60328
TD60228
TD60223
TD60227
Coupon 1
0.86
0.72
1.19
0.91
1.03
0.98
0.95
0.79
0.93
0.75
Coupon 2
0.92
0.69
0.75
1.00
0.95
0.99
0.95
0.97
0.83
0.76
Coupon 3
0.77
0.71
0.85
0.95
0.76
0.85
0.86
0.85
0.85
0.77
Coupon 4
0.85
0.80
0.94
0.99
0.75
1.01
0.95
0.93
0.69
Coupon 5
0.72
Test Average
0.85
0.73
0.93
0.96
0.87
0.96
0.93
0.87
0.5
0.74
Standard Deviation
0.06
0.04
0.19
0.04
0.14
0.07
0.05
0.07
0.05
0.03
Test Set Average ±
Standard Deviation
0.86 ± 0.13
0.92 ± 0.09
0.83 ± 0.08
Maximum L.
il Samples (0
on Test Resu
-Target Con
'00-1250 ppm) Result
__._„ ncentrati
00-2500 ppm) Results, N
Coupon set
TN51024
TN50223
TN50517
TN50519
TD60301
TD60329
TD06328
TD60228
TD60223
TD60227
Coupon 1
33.47
32.84
37.52
24.33
33.34
33.62
32.06
26.95
25.00
Coupon 2
21.19
19.57
33.67
36.24
37.33
35.45
32.80
25.40
27.75
25.35
Coupon 3
26.77
26.49
34.32
32.36
31.66
30.79
33.84
25.74
25.37
30.18
Coupon 4
26.80
32.11
33.72
37.16
31.99
27.96
24.97
26.23
Test Average
27.06
22.76
33.24
34.96
32.62
32.89
32.06
27.52
26.26
26.69
Standard Deviation
5.02
3.49
0.96
2.34
6.12
2.00
2.77
3.09
1.31
2.38
Test Set Average ±
Standard Deviation
29.95 ± 5.68
32.52 ± 3.68
e Strength,
00-1250 ppm) Resul.
ration
10-2500 ppm) Results, N
Coupon set
TN51024
TN50223
TN50517
TN50519
TD60301
TD60329
TD60328
TD60228
TD60223
TD60227
Coupon 1
0.78
0.51
0.76
0.87
0.56
0.77
0.78
0.74
0.62
0.58
Coupon 2
0.49
0.45
0.78
0.84
0.85
0.82
0.76
0.59
0.64
0.59
Coupon 3
0.62
0.61
0.80
0.75
0.73
0.71
0.78
0.60
0.59
0.70
Coupon 4
0.62
0.74
0.78
0.86
0.86
0.65
0.62
0.58
0.61
Test Average
0.63
0.52
0.77
0.81
0.75
0.79
0.74
0.64
0.61
0.62
Standard Deviation
0.12
0.08
0.02
0.05
0.14
0.06
0.06
0.07
0.03
0.06
Test Set Average ±
Standard Deviation
0.69 ± 0.13
itrol Samples (0 ppm) Day
0.76 ± 0.09
0.62 ± 0.05
-Target Concentration Days Target Concentration Days
Coupon set
TN51024
TN50223
TN50517
TN50519
TD60301
TD60329
TD60328
TD60228
TD60223
TD60227
Days in Storage
200
203
307
305
204
176
177
205
210
206
Test Set Average ±
Standard Deviation
254 ± 60
186 ± 16
207 ± 3
Note: Yellow-highlighted cells indicate that the data point was statistically determined to be an outlier within its test set but not within the test
group (four control groups); therefore, the value was retained.
-------
8.4 Discussion
Coupons were tested for maximum load in both the machine
direction and cross-machine direction; these values were then
used to calculate the MOR for each coupon type and test
direction.
For the machine direction tests, the maximum load values
were 37.17 ± 5.72 N for the control samples, 39.90 ± 3.89 N
for the half-target coupons, and 36.03 ± 3.56 N for the full-
target coupons. The MOR values for the machine direction
tests were 0.86 ± 0.13 N/mm2 for the control samples, 0.92
± 0.09 N/mm2 for the half-target coupons, and 0.83 ± 0.08
N/mm2 for the full-target coupons.
For the cross-machine tests, the maximum load values were
29.95 ± 5.68 N for the control samples, 32.52 ± 3.68 N for
the half-target coupons, and 26.82 ± 2.22 N for the full-target
coupons. The MOR values for the cross-machine direction
tests were 0.69 ± 0.13 N/mm2 for the control samples, 0.76
± 0.09 N/mm2 for the half-target coupons, and 0.62 ± 0.05
N/mm2 for the full-target coupons.
A statistical analysis of the individual test results was
conducted to detect potential statistical outliers (Q-test) and
determine whether there were any differences between the
control and exposed samples (Welch's T-test).
Only one of the individual coupons was determined to be
an outlier at the Q=0.99 confidence level (Coupon 3 of test
set TD60328, half-target concentration) within its own test
set. Because the machine direction maximum load of this
coupon was statistically significantly different from others
in the test set, the value for the MOR for that coupon was
also a statistical outlier. However, when compared to all the
other tests and coupons in the test group (half-target, machine
direction), the coupon was not significantly different and
therefore could not be rejected.
The half-target exposure coupons produced slightly higher
maximum load values and higher MOR values (on average)
than either the control or full-target coupons for both the
machine direction and the cross-machine tests. However, at
the 95% confidence level, there were no statistical differences
between the control samples and either the half- or full-target
concentration samples.
-------
Evaluation of Carpet
9.1 Introduction
The effects of CD on the physical integrity of loop pile carpet
fibers were investigated using ASTM Test Method C1335-
03 "Standard Test Method for Tuft Bind of Pile Yarn Floor
Coverings." The method determines the force required to
pull out a tuft of a pile yarn from a floor-covering sample
(see Figure 9.1). The ASTM test was used to determine
the integrity of loop pile carpet fibers exposed to vaporous
decontaminant compared to unexposed (control) loop pile
carpet fibers.
9.2 Sample Preparation
The carpet samples were removed from storage, visually
inspected, and measured. The coupons from chamber
positions 1,3,4, 5, and 7 were selected for testing in order
to obtain representation throughout the test chamber. The
samples were brought to moisture equilibrium such that the
weight of the sample did not change by more than 0.2% on
successive weighings at a minimum interval of two hours.
The sample preparation was conducted within a range of
15-24 °C and 48-75% RH. The testing was conducted in
accordance with ASTM Test Method D1335-03. The Instron
Figure 9.1: Carpet Coupon Test
fixture for the carpet test was installed prior to testing. The
Instron universal testing machine operation and calibration
verification was conducted by suspending a certified weight
from the fixture and recording the weight. Three sets of five
coupons were tested for each concentration (full-target and
half-target) and four sets were tested for the controls (0 ppm).
The load required to pull a carpet loop from the binding was
measured in N. No bias requirements have been established
for this test method. The results for control coupons were
compared to the results for decontaminant-exposed samples.
A statistical analysis of the data was conducted to determine
whether the decontaminant-exposed coupon results were
statistically different from the control coupon results.
9.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based on
the arrival of the Instron fixture for testing. The coupons for
a particular fumigation trial were studied at the same number
of days. The carpet tuft bind results and number of days in
storage is provided in Table 9.1.
Pulled Row
Pulled Carpet Loop
-------
Table 9.1: Carpet Coupon Test Results for Average Tuft Bind - CD Control Samples
•ffii|:lffi|Q
Coupon
Loop 1
Loop 2
Loop 3
Loop 4
Loop 5
Test Average
Standard Deviation
Days
Coupon
Loop 1
Loop 2
Loop 3
Loop 4
Loop 5
Test Average
Standard Deviation
Days
Test Set Average ±
Standard Deviation
Tuft Bind Force
Coupon
Loop 1
Loop 2
Loop 3
Loop 4
Loop 5
Test Average
Standard Deviation
Test Set Average ±
Standard Deviation
Days
Tuft Bind Force
Coupon
Loop 1
Loop 2
Loop 3
Loop 4
Loop 5
Test Average
Standard Deviation
Test Set Average ±
Standard Deviation
Days
#1
14.9
8.9
10.0
16.4
11.7
12.4
3.2
#2
10.8
17.0
18.2
13.8
16.4
15.2
2.9
#3
14.3
15.0
11.8
13.7
1.7
#4
20.9
19.4
18.0
19.5
1.4
#5
21.6
16.2
16.4
16.8
17.7
2.6
158
#1
11.6
13.5
18.5
21.3
13.1
15.6
4.1
#2
18.8
7.0
12.8
23.6
17.1
15.8
6.3
#3
10.7
9.2
12.5
10.8
1.7
#4
17.8
12.7
16.4
15.6
2.6
#5
15.8
15.2
14.4
15.1
0.7
159
R
#1
10.8
16.2
18.1
21.1
26.8
18.6
5.9
#2
24.3
20.2
20.9
21.8
2.2
N5050
#3
11.7
11.2
12.0
11.6
0.4
5
#4
17.0
17.3
17.7
17.4
0.4
#5
19.8
18.4
9.9
16.9
19.4
16.9
4.0
162
#1
15.1
20.1
21.9
10.4
18.3
17.1
4.5
#2
10.3
23.6
14.7
15.3
16.0
5.5
#3
29.8
15.2
14.6
20.8
22.3
20.6
6.2
#4
12.1
13.7
13.6
13.1
0.9
#5
18.1
18.4
14.7
17.1
2.0
151
16.2 ± 4.3
^Hp^^^jl
#1
26.8
24.9
26.2
25.9
1.0
#2
16.3
26.3
15.1
20.9
15.4
18.8
4.8
#3
15.8
20.8
20.8
19.1
2.9
#4
17.3
15.6
15.0
16.0
1.2
#5
18.9
14.1
22.8
13.3
24.2
18.7
5.0
:oncentration (2000-2500 ppm) Re.
#1
21.9
19.7
15.8
21.3
16.3
19.0
2.8
#2
15.7
22.8
21.4
21.6
17.0
19.7
3.1
#3
24.6
14.4
21.9
18.8
32.3
22.4
6.7
#4
18.8
13.1
21.5
21.5
18.0
18.6
3.4
#5
14.2
17.9
15.3
15.8
1.9
suits, N
#1
6.2
3.5
4.7
28.2
15.4
11.6
10.4
#2
13.4
13.0
13.1
13.2
0.2
#3
23.1
14.0
15.4
13.2
18.6
16.9
4.1
#4
23.2
15.1
16.4
27.1
22.3
20.8
5.0
#5
7.9
4.9
6.6
6.5
9.5
7.1
1.7
17.5 ± 6.1
175
#1
19.45
19.51
12.39
14.49
22.34
17.6
4.1
#2
22.13
26.96
23.43
24.2
2.5
#3
21.04
21.43
25.90
22.8
2.7
#4
25.67
29.23
31.16
28.7
2.8
#5
19.95
22.03
19.34
20.4
1.4
168
170
'• '. 3 •
#1
25.33
24.91
20.09
23.4
2.9
#2
10.95
15.71
23.97
11.58
12.10
14.9
5.4
#3
30.17
20.02
19.52
23.80
21.21
22.9
4.4
#4
17.13
20.70
14.64
15.56
17.0
2.7
#5
11.67
16.26
23.38
26.55
11.76
17.9
6.8
#1
27.00
19.56
13.40
34.52
23.13
23.5
7.9
#2
20.54
41.93
22.79
13.56
15.38
22.8
11.3
#3
32.30
25.26
11.90
26.04
42.77
27.7
11.3
#4
21.78
17.50
20.73
20.0
2.2
#5
15.24
14.80
28.66
19.91
18.84
19.5
5.6
21.3 ± 6.8
163
164
169
Notes: The blank cells are samples that were not required to be analyzed, due to
The cells highlighted in yellow were determined to be outliers according to the Q
within the test group (four control groups); therefore, the values were retained.
meeting the test method sampling criteria of +15%.
•test at the 99% confidence interval within its test set but
not
-------
9.4 Discussion
A statistical analysis of the individual test results was
conducted to detect potential statistical outliers (Q-test) and
determine whether there were any differences between the
control and exposed samples (Welch's T-test).
Although there was a great deal of scatter in the data (the
standard deviations of the results were between 27 and 35%
of the mean value within the various test groups), only one
of the individual tuft pulls from a single coupon (Tuft 1,
Coupon 3, RD60330) was significantly different from the
others from the same carpet coupon. When comparing
coupons within test groups, there was one coupon (Coupon 3,
RN50224, control group) that was significantly different from
others within the test group at the Q=0.99 confidence level.
However, it was not statistically different when compared to
all the control coupons. There were no statistical outliers in
the half-target or full-target concentration tests.
The average tuft bind pull value was 16.2 ± 4.3 N for
the control samples, 21.3 ± 6.8 N for the half-target
concentration samples, and 17.5 ± 6.1 N for the full-target
concentration samples.
A Welch's T-Test analysis was conducted on the samples to
determine whether there were statistical differences between
the control, hah0-, and full-target concentration samples.
The half-target concentration results were determined to be
statistically significantly different from both the control and
target samples at the 95% confidence level, an unexpected
result due to the large standard deviations of the three sets
of data and their respective overlaps. The control and target
concentration samples were not found to be significantly
different at the 95% confidence level. The lack of difference
for the full-target concentration samples and control samples
indicates that it is not likely that the difference between the
half-target data is due entirely to CD fumigation.
There appears to be a minor increase for the average tuft bind
results with exposure to CD, but the trend is smaller than the
standard deviations of the individual test results, so it is not
clear whether it is an experimental artifact or a real trend.
These test methods show that exposure to CD may have a
statistically significant effect on the tuft bind pull tests of
carpet; further study is required to define the nature and
magnitude of the effect.
-------
10
Evaluation of Concrete Cinder Block
10.1 Introduction
The effects of CD on the physical integrity of concrete cinder
block coupons were investigated using the compression test
as described in ASTM Test Method C140-03 "Standard Test
Methods for Sampling and Testing Concrete Masonry Units
and Related Units." The ASTM test was used to determine
the integrity of concrete cinder block coupons exposed to
vaporous decontaminant compared to unexposed (control)
concrete cinder block coupons.
10.2 Sample Preparation and Testing
The concrete cinder block samples were removed from
storage, visually inspected, and measured. The coupons
from chamber positions 1, 4, and 7 were selected for
testing in order to obtain representation throughout the test
chamber. The samples were brought to equilibrium in a
range of 16-32 °C and less than 80% RH for 48 hours prior
Figure 10.1: Concrete "Cinder Block" Coupon Test
to testing. The testing was conducted in accordance with
ASTM Test Method C140-03. The Instron fixture for the
concrete cinder block test was installed prior to testing. The
Instron universal testing machine operation and calibration
verification was conducted by suspending a certified weight
from the fixture and recording the weight. A photograph of
a test sample loaded into the Instron test fixture is shown
in Figure 10.1. Three sets of three coupons were tested for
each concentration (0 ppm, full-target, and half-target). The
load required to rupture the coupons was measured in N.
No precision or bias requirements have been established
for this test method. The results for control coupons were
compared to the results for decontaminant-exposed samples.
A statistical analysis of the data was conducted to determine
whether the decontaminant-exposed coupon results were
statistically different from the control coupon results.
-------
10.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based on
the arrival of the Instron fixture for testing. The coupons for
a particular fumigation trial were studied at the same number
of days. A photograph of a representative concrete cinder
block sample before and after testing is provided in Figure
10.2. The coloring difference between the pictures is a result
of the room lighting and is not real. Both samples were taken
on the same blue color mat. Values for the load required to
crush the concrete cinder block coupons, the coupon gross
area compressive strength results, and number of days in
storage are provided in Table 10.1. The concrete cinder block
is a heterogeneous material sample to sample. The break
patterns varied from sample to sample; a photograph of each
sample is provided in Appendix D.
Figure 10.2: Representative Concrete Coupon Before and After Testing
Before Testing
Coupon CV5060201
-------
Table 10.1: Coupon Test Results for Concrete Cinder Block
Maximum Lo
I Samples (0 ppm
-1250 ppm) Resul
-2500 ppm) Results,
Coupon set
CN50510
CN50524
CN51027
CD51129
CD51201
CD51205
CD51011
CD51012
CD51013
Coupon 1
3760
3252
4880
4243
3619
3091
5372
2959
3558
Coupon 2
3112
2711
3011
3001
4458
4107
2871
2376
3839
Coupon 3
2554
2557
3310
3074
2366
4596
3818
2790
4027
Test Average
3142
2840
3734
3439
3481
3931
4020
2708
3808
Standard Deviation
603
365
1004
697
1053
768
1262
300
236
Test Set Average ±
Standard Deviation
3239 ± 729
3617 ± 776
3512 ± 898
Compressive Str
Coupon set
CN50510
CN50524
-Target Concentra
inr>o_i250 r>"ml
ults, kgf/i
Test 2
arget Concentrate
"000-2500 ™r
suits, k
CN51027
CD51129 CD51201 CD51205
CD51011
CD51012
CD51013
Coupon 1
1.9
1.5
2.3
2.2
1.7
1.6
1.4
1.8
Coupon 2
1.5
1.4
1.6
1.3
2.1
1.4
1.1
2.1
Coupon 3
1.1
1.2
1.7
1.5
1.2
2.0
1.3
Test Average
1.5
1.4
1.9
1.7
1.7
2.0
1.3
Standard Deviation
0.4
0.2
0.4
0.5
0.5
0.3
0.7
0.1
0.2
Test Set Average ±
Standard Deviation
1.6 ± 0.4
1.7 ± 0.4
1.7 ± 0.5
Number of Days in Control Samples (0 ppm)
torage
et Conce.
Coupon set
CN50510
CN50524
CN51027
CD51129
CD51201
CD51205
CD51011
CD51012
CD51013
Coupon 1
126
127
219
128
126
211
162
211
160
Coupon 2
126
127
219
128
126
211
162
211
160
Coupon 3
126
127
219
128
126
211
162
211
160
Test Set Average ±
Standard Deviation
157 ± 46
155 ± 42
178 ± 25
10.4 Discussion
A statistical analysis of the individual test results was
conducted to detect potential statistical outliers (Q-test) and
determine whether there was a difference between the control
and exposed samples (Welch's T-test). Within individual test
runs for both maximum load and gross area compressive
strength, there were no statistical outliers.
The values for the maximum load tests for concrete cinder
blocks were 3239 ± 729 kgf for the control samples, 3617 ±
776 kgf for the half-target concentration samples, and 3512
± 898 kgf for the full-target concentration samples. The
values calculated for the gross compressive strength of the
cinder block samples were 1.6 ± 0.4 kgf/mm2 for the control
samples, 1.7 ± 0.4 kgf/mm2 for the half-target samples, and
1.7 ± 0.5 kgf/mm2 for the full-target samples.
Comparing individual test set averages and gross area
compressive strength within test groups, there were no
statistical outliers.
When the averages for the exposed and nonexposed coupons
are compared, we find no statistical differences among
them. The Welch's T-test evaluation of the data indicates
no statistically significant differences among the means
of the exposed and control samples at the 95% confidence
level. These test methods show that exposure to CD has no
statistically significant effect on the maximum load or the
gross area compressive strength of the cinder blocks tested.
-------
11
Evaluation of Wood
11.1 Introduction
The effects of CD on the physical integrity of wood were
investigated using the bending edge-wise test as described in
ASTM Test Method D4761-02a "Standard Test Methods for
Mechanical Properties of Lumber and Wood-Base Structural
Material," Sections 6 to 11. The ASTM test was used to
determine the integrity of wood coupons exposed to vaporous
decontaminant compared to unexposed (control) wood
coupons.
11.2 Sample Preparation
The wood samples were removed from storage, visually
inspected, and measured. The coupons from chamber
positions 1, 4, 7, 10, and 14 were selected for testing in order
to obtain representation throughout the test chamber. The
samples were brought to moisture equilibrium such that the
weight of the sample did not change by more than 0.2% on
successive weighings at a minimum interval of two hours.
The sample preparation was conducted within a range of
15-25 °C and 48-75% RH. The testing was conducted in
accordance with ASTM Test Method D4761-02a. The Instron
fixture for the wood test was installed prior to testing. The
Instron universal testing machine operation and calibration
verification was conducted by suspending a certified weight
from the fixture and recording the weight. Three sets of
Figure 11.1: Wood Coupon Test
five coupons were tested for each concentration (full-target
and half-target), and four sets were tested for the controls
(0 ppm). The load required to rupture the wood coupons
was measured in N. No precision or bias requirements have
been established for this test method. The results for control
coupons were compared to the results for decontaminant-
exposed samples. A statistical analysis of the data was
conducted to determine whether the decontaminant-exposed
coupon results were statistically different from the control
coupon results. A photograph of a wood sample loaded into
the Instron is provided in Figure 11.1.
11.3 Results
The coupons were stored for at least 90 days after
fumigation. The actual number of storage days was based on
the arrival of the Instron fixtures for testing. The coupons for
a particular fumigation trial were studied at the same number
of days. A photograph of a representative wood sample
before and after testing is provided in Figure 11.2. Values
for the wood coupon results for the required load and time
to break, moisture content, and number of days in storage
are provided in Table 11.1. The wood samples vary slightly
in knot and grain pattern from sample to sample. The break
patterns varied from sample to sample; a photograph of each
sample is provided in Appendix C.
Figure 11.2: Representative Wood Coupon Before and After Testing
-------
Table 11.1: CD Coupon Test Results for Wood
Maximum F
. Samples (0 ppm) Res
alf-Target Concentratioi
00-1250 ppm) Results
et Concentrati
00-2500 ppm) Results
Coupon set
WN50307
WN50317
WN50502
WN50504
WD60213
WD60207
WD60209
WD51206
WD51207
WD51208
Coupon 1
4945
3903
4516
4600
2360
4163
4712
4683
1906
3037
Coupon 2
2433
3546
5582
3248
3766
4714
4289
4514
3027
3860
Coupon 3
5130
2574
4031
5233
3312
3994
7141
3699
3516
3131
Coupon 4
3592
3494
6370
5170
3702
3651
3779
3741
4427
3095
Coupon 5
4825
4446
3475
4545
4015
4983
6553
4193
2995
3543
Test Average
4185
3593
4795
4559
3431
4301
5295
4166
3174
3333
Standard Deviation
1151
684
1173
798
650
541
1470
444
915
356
Test Set Average ±
Standard Deviation
4283 ± 1009
4342 ± 1201
3558 ± 731
Gross Ar
Compressive
Strengt
ppm; mini
alf-Target Concentratio
000-1250 ppr
Results, min.
Target Concentration
(2000-2500 ppm)
Results, min.
Coupon set
WN50307
WN50317
WN50502
WN50504
WD60213
WD60207
WD60209
WD51206
WD51207
WD51208
Coupon 1
4.9
3.9
4.3
4.6
2.4
4.1
4.7
4.7
1.9
3.0
Coupon 2
2.4
3.6
5.6
3.7
4.7
4.3
4.5
3.0
3.9
Coupon 3
5.1
2.6
4.0
5.2
3.3
4.0
3.7
3.5
3.1
Coupon 4
3.6
3.5
6.1
4.6
3.7
3.6
3.7
4.3
3.1
Coupon 5
4.4
3.4
4.4
4.0
5.0
4.5
4.2
2.9
3.5
Test Average
4.2
3.6
4.7
4.4
3.4
4.3
4.4
4.2
3.1
3.3
Standard Deviation
1.1
0.7
1.1
0.7
0.6
0.5
0.4
0.4
0.9
0.4
Test Set Average ±
Standard Deviation
4.2 ± 1.0
Moistur
Conten
4.0 ± 0.7
Target Concentr
000-1250 ppr
3.5 ±0.7
Target Concentration
(2000-2500 ppm)
Coupon set
WN50307
WN50317
WN50502
WN50504
WD60213
WD60207
WD60209
WD51206
WD51207
WD51208
Coupon 1
0.12
-0.12
-0.40
-0.18
0.03
0.07
-1.00
-0.93
-0.84
Coupon 2
0.20
-0.17
-0.33
-0.14
0.11
0.00
-1.27
-1.31
-1.27
Coupon 3
0.17
-0.14
-16.61
-0.03
0.13
0.02
-1.29
-1.39
-1.30
Coupon 4
0.12
-0.13
-17.29
-0.12
0.14
0.00
-1.34
-1.39
-1.67
Coupon 5
0.17
-0.13
-0.24
-0.12
0.20
0.00
-1.53
-1.15
-1.00
Test Average
0.15
-0.14
-6.98
-0.12
0.13
0.02
-1.29
-1.24
-1.21
Standard Deviation
0.03
0.02
9.11
0.05
0.06
0.03
0.19
0.20
0.32
Test Set Average ±
Standard Deviation
-2.32 ± 5.95
0.01 ± 0.11
-1.24 ± 0.23
Number of Days
in Stora
ontrol Samples (0 ppm) Days
Coupon set
WN50307
WN50317
WN50502
rgei uoncen
Days
WN50504
WD60213
WD60207
largei uoncemrauon
Days
WD60209
WD51206
WD51207
WD51208
Coupon 1
135
125
182
372
220
227
225
149
148
147
Coupon 2
135
125
182
372
220
227
225
149
148
147
Coupon 3
135
125
182
372
220
227
225
149
148
147
Coupon 4
135
125
182
372
220
227
225
149
148
147
Coupon 5
135
125
182
372
220
227
225
149
148
147
Test Set Average ±
Standard Deviation
204 ± 102
224 ± 3
148 ± 1
Note: Yellow cells indicate that no data were collected.
-------
11.4 Discussion
Of the 50 coupons tested to destruction in this portion of
the program, no coupons could be eliminated as statistical
outliers from within their individual test sets or test groups
(control, half-target concentration, or full-target concentration
samples) at the Q=0.99 level of confidence.
With regard to the data from the test group of coupons,
the average maximum load values for the half-target CD
exposed coupons increased slightly (~1%) over the value for
the control set, while the maximum load dropped by 17%
for the full-target concentration coupons; relative standard
deviations were on the order of 21-28%. The average
maximum force value for the control samples was 4283
± 1009 N. The half-target concentration samples had an
average maximum force value of 4342 ± 1201 N (an increase
of 1.4%), while the full-target concentration samples had an
average maximum force value of 3558 ± 731 N (a decrease
of 17.4% from the control group). The maximum force
for the full-target concentration exposed coupons was
statistically significantly different from both the controls
and from the half-target concentration coupons at a 95%
confidence level using the Welch's T-test results.
Average time-to-break value for the control coupons was
4.1 ± 0.9 seconds; the half-target concentration coupons
was 4.0 ± 0.7 seconds (a 2% decrease), and the full-target
concentration coupons was 3.5 ± 0.7 seconds (a 15%
decrease). The time-to-break values for the exposed coupons
showed a slight downward trend. Welch's T-Test was again
used to compare the time-to-break values of the different
groups of coupons. At the 95% confidence level, the full-
target concentration coupons were found to be significantly
different from the control and the half-target coupons.
The average change in moisture content for the control
samples after storage was -2.32 ± 5.95%. For the half-
target concentration coupons, the average change in
moisture content was +0.01 ± 0.11, and for the full-target
concentration coupons the average change in moisture
content was -1.24 ± 0.23%. The changes in moisture content
were not suggested to be statistically significantly different at
the 95% confidence level using the Welch's T-test.
The results suggest that fumigation under the full-target
conditions used in this study may impact the force required to
break the structural wood, in accordance with the ATSM test
method used. At the higher fumigant concentration, the wood
samples required less force and time to break than either the
controls or half-target samples.
-------
12
Evaluation of Electrical Circuit Breakers
12.1 Introduction
The impact of fumigant and humidity on the performance
of electrical circuit breakers was also investigated in this
study. This investigation involved circuit breakers prepared
as baseline, test, and control. Baseline circuit breakers were
the "as-purchased" circuit breakers. The test circuit breakers
were prepared in the exposure chambers using fumigant.
The control circuit breakers were prepared in the exposure
chambers using a temperature and relative humidity profile
similar to that of the test breakers.
12.2 Sample Preparation
The single-pole, 20-amperes rated circuit breakers were
purchased from Home Depot (model HOM120). All of
the circuit breakers were installed in the testing stations to
confirm that they were operational before exposure testing,
and all were removed from the stations, numbered, and chain-
of-custody initiated. The baseline circuit breakers were put
aside until needed. The test and control exposure testing was
discussed in Section 4. Each run used seven circuit breakers.
Figure 12.1: Circuit Breaker Test Station
After a test or control circuit breaker set was prepared in
the exposure chamber, the breakers were removed from the
exposure chamber and visually inspected.
12.3 Circuit Breaker Testing Stations
After visual inspection, the breakers were installed in the
testing station and observed for 90 days under load. A
photograph of the testing station is shown in Figure 12.3.
The testing station is an electrical box containing 8 spaces,
16 circuits, 100 amp max from square D (Home Depot #
577-340). The circuit breaker box was wired with 12-gauge,
20-amp wire into the 120-V outlet. Each circuit breaker was
wired in series with an electrical lamp (s513e) with an outlet
box (sllOe) manufactured by Thomas & Bretts (Home Depot
# c214477 and b214426, respectively). Each lamp contained
a Phillips 40-watt light bulb (Home Depot #a356140). The
test or control circuit breakers were installed into slots 1
through 7, and the baseline circuit breaker was installed in
slot 8 (Figure 12.1, upper left picture). The room temperature
and relative humidity were monitored daily.
-------
12.4 Results
The circuit breakers were exposed to fumigant and visually
inspected after removal from the exposure chamber.
No damage was observed on any of the circuit breakers
following fumigation. The circuit breakers were then installed
into the testing stations for 90 days. The stations were
observed on each work day and light bulbs were replaced as
needed. No breakers failed during the 90-day storage under
load. Following the 90-day storage, the breakers were tested
using current-time measurements done at 150% (30 amp) and
Table 12.1: Chlorine Dioxide Circuit Breaker Test Results
300% (60 amp) of the breakers' rated value. Tests were done
using an AVO/multi-amp MS-2, available from Advanced
Test Equipment Rentals. The test results are provided in
Table 12.1. The circuit breaker data was statistically analyzed
to determine whether the breaker was compromised after
exposure to decontaminant by comparing the test results
obtained with fumigant-exposed circuit breakers to those
obtained with control coupons (not exposed to fumigant).
Each breaker station contained one control breaker that had
not been exposed in the chamber.
6-hour CD Box Test
•r CD Cont
30-Amp Test Time
BD5090601
4.65
223.70
BN5022501
5.37
43.21
BD5090602
5.16
82.72
GN5022502
5.81
57.52
BD5090603
4.53
90.65
BN5022503
5.47
55.42
BD5090604
6.59
81.82
BN5022504
5.75
61.22
BD5090605
5.05
115.87
BN5022505
4.85
48.62
BD5090606
3.45
64.91
BN5022506
50.31
BD5090607
NA
64.87
BN5022507
5.37
48.45
BN5022506 Retest
55.48
Baseline Breaker
6.08
62.14
Baseline Breaker
4.97
41.47
Test Average
4.91
103.51
Test Average
5.45
52.53
Standard Deviation
BD5091501
1.02
5.34
55.75
Standard Deviation
61.25
BN5022801
0.32
5.54
5.87
57.50
BD5091502
4.40
90.23
BN5022802
5.59
51.08
BD5091503
5.14
68.25
BN5022803
6.41
55.60
BD5091504
6.11
60.9
BN5022804
2.99
53.29
BD5091505
3.05
53.95
BN5022805
6.00
51.94
BD5091506
4.81
64.55
BN5022806
5.41
68.59
BD5091507
3.64
76.42
BN5022807
5.98
48.79
Baseline Breaker
3.28
60.99
Baseline Breaker
5.68
63.89
Test Average
4.64
67.94
Test Average
5.42
55.26
Standard Deviation
1.04
12.04
Standard Deviation
1.12
6.55
The measurement for the analysis was the time for the circuit
breaker to open (Time-to-Open) when experiencing a current
above its rated value. A circuit breaker that trips too quickly
will protect personnel and equipment but can represent a
significant loss of time and productivity. A circuit breaker
that takes too long to trip could result in a heat buildup, and
possibly a fire, and might fail to protect equipment, users, and
property.
A statistical analysis of the individual test results was
conducted to detect potential statistical outliers (Q-test) and
determine whether there were any differences between the
control and exposed samples (Welch's T-test) in the tests of
circuit breakers exposed to CD.
The differing test groups were first checked to determine
whether there were any statistical outliers using the Q-test.
There were two statistical outliers found in the data at the
Q=0.99 level of confidence: Circuit breaker BD5090601 from
the 6-hour control tested at the 30-amp challenge and circuit
breaker BN5022804 from the 12-hour exposed group tested
with the 60-amp challenge. These data points are highlighted
in orange in Table 12.1 and were discarded; the remainder of
the statistical analysis was conducted without them.
Table 12.2 summarizes the data for the average and standard
deviation for the various test groups. The Welch's T-test
was used with a 95% confidence level in order to determine
whether the changes in the Time-to-Open were significantly
different among the different treatment (control, 1000 ppm,
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or 2000 ppm) and analysis challenge (30-amp or 60-amp)
groupings. At the 60-amp challenge, the slight decreases in
the Time-to-Open for the circuit breakers exposed to the CD
fumigation conditions compared to their respective controls
were not statistically significant. In addition, no statistically
significant difference was observed due to exposure to the
control conditions for 6 compared to 12 hours, nor as a
function of fumigation conditions.
However, at the 30-amp challenge, the decrease in the Time-
to-Open for the circuit breakers exposed to 2000 ppm of CD
for 6 hours was statistically significantly different from the
corresponding 6-hour control. At the lower concentration
and longer fumigation time, the observed slight increase
in Time-to-Open compared to the 12-hour control was not
a statistically significant difference. As with the 60-amp
challenge, no statistically significant difference was observed
due to exposure to the control conditions for 6 compared to
12 hours. In addition, the observed difference in the Time-
to-Open for the 6 hour versus 12 hour CD-exposed circuit
breakers was also not statistically significant.
The results are somewhat conflicting, i.e., no statistically
significant difference between the 6-hour and 12-hour CD
exposure for the 60-amp challenge. However, it appears that
exposure to the higher concentration of CD may have an
effect on the performance of circuit breakers as determined
from the Time-to-Open testing based on the comparison
to the control. The results suggest that exposure to lower
CD concentrations for longer times, rather than higher
concentrations for shorter times, may have less deleterious
effects on the circuit breakers. No specification was found to
determine whether the observed effect at the 2000-ppm CD
fumigation condition was within the device failure criteria.
Table 12.2: Summary of Time-to-Open Data
6-Hour Control
6-Hour @ 2000 ppm CD
12-Hour Control
12-Hour @ 1000 ppm CD
52.53 + 5.87
83.47 + 18.95
55.26+ 6.55
67.94+ 12.04
5.45 + 0.32
4.91 + 1.02
5.82 + 0.38
4.64+ 1.04
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13
Chlorine Dioxide Fate on Metals
13.1 Introduction
This study characterized the interaction of CD with
aluminum, copper, and steel — materials common in
electrical systems. Residual chloride by-products on the
metals following treatment with CD were analyzed using
ion chromatography. Analyses for other possible reaction
products such as metal hydroxides and oxides were not
attempted. The objective of this study was to identify the
anionic chlorine species and concentrations formed on
aluminum, steel, and copper after exposure to CD at 1000
and 2000 ppm (parts per million volume) for 12 and 6
hours, respectively.
13.2 Test Procedure
Aluminum (0.5" W x 0.5" L), copper (0.5" D x 0.5" L), and
steel EMT conduit (0.5" D x 0.5") coupons were exposed to
CD to determine the fate of the decontaminant on the metals.
Coupons cut from metals purchased from Home Depot were
exposed to chlorine dioxide concentrations of 1000 and 2000
ppm for 12 and 6 h, respectively, to give a total CT of 12000
ppm-hr for each experiment. The metals were exposed at
25 °C, 75-90% RH; control sets were exposed under the
same conditions at 0 ppm CD. Fourteen coupons of each
metal in small plastic containers were placed on the inside
bottom of a PlasLabs model 830-ABC glove box (PlasLabs,
Inc., Lansing, MI) during each exposure. The coupons were
removed from the glove box after exposure and stored for
90 days in the plastic containers. After storage, each of the
14 coupons was placed in a 2-ounce wide-mouth glass jar
with cap. Chloride, chlorite, chlorate, perchlorate, and other
anions were removed from each sample by extraction in
water (10 mL) with rocking. The extracts were then passed
through a 0.22-jjun syringe filter and injected directly into
the chromatograph to determine retention time and detector
response for each analyte present in the sample.9 Dilution of
samples with deionized distilled water was conducted when
appropriate. The anions were then identified and quantified
by comparison with standard solutions.
13.3 Sample Analyses
Sodium carbonate (analytical-grade) and HPLC-grade
methanol used in preparing the mobile phase was purchased
from Fisher Scientific (Fair Lawn, NJ). The chloride,
chlorate, and perchlorate anion standards were obtained
from SCP Scientific, Champlain, NY, and the chlorite anion
standard was obtained from HPS Science, Charleston, SC.
The analyses were carried out using an ion chromatograph
with a Millenniums 2 Data Workstation equipped with a
Rheodyne 7725 li Injector, a Model 510 Pump, and a Model
432 Conductivity Detector (Waters Corporation, Milford,
MA). Conductivity suppression was carried out using
anERIS 1000HP Autosuppressor (Alltech Corporation,
Deerfield, IL).
Analyses for chloride, chlorite, and chlorate in the extracts
were performed under the following conditions: column,
ION-PAC AS9HC (Dionex Corporation, Sunnyvale,
CA); mobile phase, 9 mM Na2CO3; flow rate, 1.0 mL/
min; injection volume, 20 jjuL; and detection, suppressed
conductivity (1 SFS). Standard solutions of each anion
were injected onto the column and retention times of each
analyte were determined. Calibration curves were obtained
by injecting known concentrations (100, 40, 10, 1, and
0.4 |jig/mL) of each anion in deionized water into the
chromatograph in duplicate and measuring the conductivity
response obtained.
Analysis of the extracts for perchlorate were performed under
the following conditions: column, ION-PAC AS 14 (4 mm)
(Dionex Corporation, Sunnyvale, CA); mobile phase, 9 mM
Na2CO3 in 40% methanol; flow rate, 1.0 mL/min., injection
volume, 20 jjuL; detection, suppressed conductivity (1 SFS).
Standard solutions of perchlorate were injected onto the
column and a retention time was determined. A calibration
curve of perchlorate ion was obtained by injecting a known
concentration (100, 40, 10, 4, 1, 0.4 jjug/mL) of the anion
in deionized water into the chromatograph in duplicate and
measuring the conductivity response.
The detector response versus concentration for all of the
species was determined to be linear. A typical regression line
for each was determined using the least square method. The
regression curve and linear correlation coefficient (R2) for
each target analyte were determined to be as follows:
• chloride, y = 118486x -136041 (R2 = 0.9987)
• chlorite, y = 42201x -53598 (R2 = 0.9979)
• chlorate, y = 49100x - 43882 (R2 = 0.9982
• perchlorate, y = 151113x- 135662 (R2 = 0.9996)
The reproducibility was determined to be within ±5 % of
the mean.
Analyte standards at the 10 jjug/mL concentration level
were injected before and after a daily analytical run, with
reproducibility having to be within ±10% of the mean.
The unknown concentration of each species in the extracts
was determined by correlating the detector response to
the response versus concentration curve (standard curve)
obtained for each target analyte. The detector response was
substituted into the appropriate regression equation and the
corresponding concentration was calculated.
13.4 Results
A summary of the CD reactions on aluminum, copper, and
iron with the corresponding products and concentrations
is provided in Table 13.1. A comparison of copper tubing
exposed and not exposed to CD is provided in Figures 13.1
and 13.2. A layer of patina is evident on the tubing exposed to
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chlorine dioxide (Figure 13.2). Ion chromatography analyses
of the extraction solvents from the aluminum controls
detected chloride ions (1.59 (jug), chlorite ions (7.96 (jug),
and chlorate ions (11.83 (jug). Analyses of iron and copper
controls identified only chloride ions, 14.58 and 31.78 (jug,
respectively.
The reaction of CD (6 h at ~ 2000 ppm) with aluminum
yielded four metal salts: A1C13, A1(C1O2)3, A1(C1O3)3, and
A1(C1O4)3. Decomposition at the lower concentration
of chlorine dioxide (12 h at ~ 1000 ppm) produced only
chloride, chlorite, and chlorate ions. The amounts of anions,
except for chloride, were greater in the reaction with the
higher concentration of CD.
Table 13.1: Residual Anions on Metal Coupons After Exposure to Chlorine Dioxide
The reaction of CD with iron gave three metal salts: FeCl3,
Fe(ClO3)3, and Fe(ClO4)3. Decomposition in 2000 ppmv
(6 h) CD gave about 39% more chloride than at 1000 ppmv
(12 h); however, the amounts of the other anions were similar
between the two reactions.
Decomposition of CD on copper (12 h at 1000 ppm CD)
yielded CuCl2 (most abundant), Cu(ClO3)2, and Cu(ClO4)2
complexes. CD (6 h at 2000 ppmv) produced predominantly
chloride and a relatively lower concentration of chlorate ions.
iNCENTRATIC
Aluminum (control)
1.59
7.96
11.83
BDL*
Aluminum (6 h ~ 2000 ppmv)
933.5
31.48
45.48
Aluminum (12 h ~ 1000 ppmv)
1,314
19.72
15.76
BDL*
Iron (control)
14.58
BDL*
BDL*
BDL*
Iron (6 h - 2000 ppmv)
22,383
BDL*
26.52
39.46
Iron (12 h - 1000 ppmv)
16,062
BDL*
21.79
37.60
Copper (control)
31.78
BDL*
BDL*
BDL*
Copper (6 h - 2000 ppmv)
942.5
BDL*
40.59
BDL*
Copper (12 h - 1000 ppmv)
1,630
BDL*
76.78
37.46
*Below the detection limit (<0.4 jxg)
Figure 13.1: Copper Tubing Prior to Exposure to Chlorine Dioxide
Figure 13.2: Copper Tubing After Exposure to Chlorine Dioxide
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14
Quality Assurance Findings
Three technical audits of the Instron destructive testing 2006, involved wood and gypsum wallboard samples
process on CD-fumigated coupons were conducted over the fumigated with CD. All operations were conducted in
course of the program. The first technical audit, conducted accordance with the applicable SOPs and lOPs. Data
6 June 2005, covered steel coupons from a control run in quality audits were conducted on 8 of the 63 CD material
the CD chamber. A second technical audit, conducted on 21 compatibility tests (13%). All were found to be acceptable,
September 2006, involved carpet samples fumigated with in accordance with the Quality Assurance Project Plan.
CD. A third technical audit, conducted on 22 September
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Literature Cited
1. Brickhouse, M.D. Quality "Assurance Project Plan and Work Plan for Deposition Velocity Studies:
Materials Sorption of Vaporized Hydrogen Peroxide or Chlorine Dioxide, Doc. No. DSQAPP2004DV,"
2004.
2. "Quality Management Plan (QMP) for the National Homeland Security Research Center (NHSRC) Office
of Research and Development (ORD)," U.S. Environmental Protection Agency (U.S. EPA), 2003.
3. "Quality Management Plan for Environmental Programs," Edgewood Chemical Biological Center
Research, Development and Engineering Command, 2003.
4. "EPA Guidance for Data Quality Assessment, Practical Methods for Data Analysis, EPA QA/G-9," U.S.
Environmental Protection Agency, 2000.
5. "EPA Requirements for Quality Assurance Project Plans, EPA QA/R-5," U.S. Environmental Protection
Agency, 2001.
6. "EPA Guidance for Quality Assurance Project Plans. EPA QA/G-5," U.S. Environmental Protection
Agency, 2002.
7. "EPA Guidance on Environmental Data Verification and Data Validation, EPA QA/G-8," U.S.
Environmental Protection Agency, 2002.
8. Brickhouse, M.D. "Quality Assurance Project Plan and Work Plan for Effects of Vaporized
Decontamination Systems on Selected Building Interior Materials, Doc. No. DSQAPP2004MC," 2004.
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Appendix A:
Coupon Identifier Code
All coupons were marked with an ID number that consisted
of a nine-character alphanumeric code. A description of the
identifier pattern and an example code are shown below.
Code Pattern
Character Explanation
1 Material
W = wood
G = gypsum
S = A572 steel
T = acoustic ceiling tile
C = concrete cinder block
R = carpet
B = circuit breakers
A = Aluminum coupons
F = Copper coupons
E = Steel coupons
2 Fumigant
V = VHP
D = chlorine
N = no fumigant
Test start date
3 year for example: 4 = 2004
4,5 month for example: 06 = June
6,7 day for example: 10 = the 10th of a mo nth
8,9 Chamber position (see IOP DS04016 figure 1)
Example GV4101104
Gypsum Wallboard with test start date of
October 11th, 2004, sample number 4.
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Figure A.I: IOP DS04016 Figure 1, "Coupon Placement in Chambers"
a) Concrete
b) Carpet
d) Steel
c) Tile
HDn
Coupons shown on rack shelves from direction of glove box transfer chamber. Pictoral
coupon scaling for length and width is (0.75 * 2 *(cm /10)).
Figure A.2: IOP DS04016 Figure 2, "Circuit Breaker Placement in Chambers"
a) Circuit Breakers
Coupons shown on rack shelves from
direction of glove box transfer chamber.
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Appendix B:
Detailed Coupon Preparation
and Inspection Procedures
COUPON PREPARATION PROCEDURE
The coupon preparation, unless otherwise noted, was
conducted at the Edgewood Chemical Biological Center
Experimental Fabrication Shop.
Mechanically Graded Lumber (Bare Wood)
• Stock Item Description: 2 x 4 x 8 KD WW/SPF Stud
• Supplier/Source: Home Depot; Edgewood, Maryland
• Coupon Dimensions: 10 in. x 1 1A in. x 1A in.
• Preparation of Coupon:
- The machined ends of the stock were discarded by
removing > 1A in. of the machined end. Coupons
were cut from stock using a table saw equipped
with an 80-tooth crosscut blade.
Latex-Painted Gypsum Wai I board
• Stock Item Description: 1A in. 4 ft. x 8 ft. Drywall
• Supplier/Source: Home Depot;
Edgewood, Maryland
• Coupon Dimensions: 6 in. x 6 in. x 1A in.
• Preparation of Coupon:
- The ASTM method requires that the samples be
taken from the interior of the material rather than
from the edge (machined edge). The machined
edges of the stock were discarded by cutting away
> 4 inches from each side.
- Coupons were cut from stock using a table saw
equipped with an 80-tooth crosscut blade.
- The 6 in. x 6 in. coupons were painted with 1 mil
of Glidden PVA Primer and followed by 1-2 mils
of Glidden latex topcoat. The primed coupons
were allowed to stand for > 24 hours prior to the
application of the topcoat.
- All six sides of the 6 in. x 6 in. 1A in. coupon were
painted.
Concrete Cinder Block
• Stock Item Description: 8 in. x 16 in. x 1 1A in.
concrete cinder block cap
• Supplier/Source: York Supply; Aberdeen, Maryland
• Original Coupon Dimensions: 4 in. x 8 in. x 1 1A in.
• Modified Coupon Dimensions: 4 in. x 8 in. x 1A in.
• Preparation of Coupon:
- Coupons were cut from stock using a water-jet.
- Four coupons were cut from each stock piece.
- Original dimensions, too large for material testing.
o Each coupon was cut into three sections.
o Two sections were measured at modified
coupon dimensions
o The third section was discarded.
Carpet
• Stock Item Description: 12-ft. Powerhouse 20
Tradewind
• Supplier/Source: Home Depot; Edgewood, Maryland
• Coupon Dimensions: 6 in. x 8 in.
• Preparation of Coupon:
- Coupons were cut from the stock using a utility
knife.
- The longer direction (8 in.) was cut parallel to the
machine edge.
- The machined edge was discarded by removing
> !/2 in.
Painted Structural Steel
• Stock Item Description: A572 Grade 50, 4 ft. x 8 ft. x
!/4 in.
• Supplier/Source: Specialized Metals
• Coupon Dimensions: 1A in. x 12 in. total, dog bone
shaped with 2 in. wide at ends,
3/4 in. wide at center
• Preparation of Coupon:
- Coupons were cut from stock using a water-jet.
- A visual observation was conducted on each
coupon to determine whether size and shape had
deviated from the required dimension. If so, the
coupon was discarded.
- Coupons were cleaned and degreased following
procedures outlined in TTC-490.
- Coupons were prepared for painting per TT-P-645
with red oxide primer.
The Edgewood Chemical Biological Center
Experimental Fabrication Shop prepared the
materials in accordance with the standards used for
the preparation and painting of steel. TTC-490 is
a federal standard providing cleaning methods and
pretreatment for iron surfaces prior to application
of organic coatings. The pretreatment is the
application of a zinc phosphate corrosion inhibitor.
TT-P-645 is a federal standard for the application
of alkyd paint. These standards were not obtained
through this program but were purchased by the
shop for their work.
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Ceiling Suspension Tile
• Stock Item Description: Armstrong 954,
Classic Fine-Textured,
24 in. x 24 in. x 9/16 in.
• Supplier/Source: Home Depot; Edgewood, Maryland
• Coupon Dimensions: 12 in. x 3 in. x 9/16 in.
• Preparation of Coupon:
- Coupons were cut from stock using a table saw
equipped with an 80-tooth crosscut blade.
- Sixteen samples were removed from each stock
item.
COUPON INSPECTION PROCEDURE
All coupons were inspected prior to testing to ensure that the
material being used was in suitable condition. Coupons were
rejected if there were cracks, breaks, dents, or defects beyond
what are typical for the type of material. In addition, coupons
were measured to verify the dimensions. Coupons deviating
from the dimension ranges listed below were discarded.
Mechanically Graded Lumber (Bare Wood)
Latex-Painted Gypsum Wallboard
Concrete Cinder Block
Carpet
Painted Structural Steel
Ceiling Suspension Tile
10 in. ± 1/16 in. x 1.5 in. ± 1/16 in. x 0.5 in. ± 1/32 in.
6 in. ± 1/16 in. x 6 in. ± 1/16 in. x 0.5 in. ± 1/16 in.
4 in. ± l/2 in. x 8 in. ± l/2 in. x 0.5 in. ± 1/16 in.
6 in. ± 1/8 in. x 8 in. ± 1/8 in.
1/4 in. ± 1/128 in. x 12 in. ± 1/16 in. with 2 in. ± 1/16 in. wide at ends,
% in. ± 1/16 in. wide at center
12 in. ± 1/8 in. x 3 in. ± 1/16 in. x 9/16 in. ± 1/16 in.
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Appendix C:
Wood Coupon Location of Break
The ASTM test method requires reporting the location of the are used on samples where the photograph contrast may not
break for each wood sample. The purpose of this appendix is clearly show the location of the break.
to provide this information in pictorial form. Yellow arrows
Figure C-l: Location of Break, Wood Coupons - Chlorine Dioxide Control Set
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Figure C-2: Location of Break, Wood Coupons - Chlorine Dioxide 1000-ppm Set
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Figure C-3: Location of Break, Wood Coupons - Chlorine Dioxide 2000-ppm Set
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Appendix D:
Concrete Cinder Block Coupon
Location of Break
Figure D-l: Location of Break, Block Coupons - CD Control Set
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Figure D-2: Location of Break, Block Coupons - CD 1000-ppm Set
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Figure D-3: Location of Break, Block Coupons - CD 2000-ppm Set
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$EPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGES FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development
National Homeland Security Research Center
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
Recycled/Recyclable
Printed with vegetable-based ink on
paper that contains a minimum of
50% post-consumer fiber content
processed chlorine free
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