EPA/600/R-20/171 | August 2020
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
&EPA
Compatibility of Electronic
Equipment and Other Materials
with Peracetic Acid Fog and
Low Concentration Hydrogen
Peroxide Vapor
Office of Research and Development
Homeland Security Research Program
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oEPA
EPA 600/R-20/171
Compatibility of Electronic Equipment and
Other Materials with Peracetic Acid Fog and
Low Concentration Hydrogen Peroxide Vapor
Center for Environmental Solutions and Emergency Response
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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Disclaimer
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development's
(ORD) Homeland Security Research Program, funded and directed this investigation through contract
EP-C-15-008 with Jacobs Technology Inc. This report has been peer and administratively reviewed and
has been approved for publication as an EPA document. It does not necessarily reflect the views of the
Agency. No official endorsement should be inferred. EPA does not endorse the purchase or sale of any
commercial products or services.
Questions concerning this document, or its application should be addressed to:
Joseph Wood
Office of Research and Development
U.S. Environmental Protection Agency (MD-E343-06)
109. T.W. Alexander Drive
Research Triangle Park, NC 27711
Phone: 919-541-5029
E-mail: wood.ioeffiepa.gov
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the
ability of natural systems to support and nurture life. To meet this mandate, EPA's research program is
providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The Center for Environmental Solutions and Emergency Response (CESER) within the Office of Research
and Development (ORD) conducts applied, stakeholder-driven research and provides responsive
technical support to help solve the Nation's environmental challenges. The Center's research focuses on
innovative approaches to address environmental challenges associated with the built environment. We
develop technologies and decision-support tools to help safeguard public water systems and
groundwater, guide sustainable materials management, remediate sites from traditional contamination
sources and emerging environmental stressors, and address potential threats from terrorism and
natural disasters. CESER collaborates with both public and private sector partners to foster technologies
that improve the effectiveness and reduce the cost of compliance, while anticipating emerging
problems. We provide technical support to EPA regions and programs, states, tribal nations, and federal
partners, and serve as the interagency liaison for EPA in homeland security research and technology.
The Center is a leader in providing scientific solutions to protect human health and the environment.
Gregory Sayles, Director
Center for Environmental Solutions and Emergency Response
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Acknowledgements
The principal investigator from the U.S. Environmental Protection Agency (EPA) directed
this effort with the support of a project team from across EPA. The contributions of the individuals
listed below have been a valued asset throughout this effort.
EPA Project Team
Joseph Wood, Principal Investigator, Center for Environmental Solutions and Emergency
Response/Homeland Security Materials Management Division (CESER/HSMMD)
Shannon Serre, Office of Land and Emergency Management/Chemical, Biological, Radiological, and
Nuclear Consequence Management Advisory Division (OLEM/CMAD)
Leroy Mickelsen, OLEM/CMAD
EPA Quality Assurance
Ramona Sherman, CESER/HSMMD
Jacobs Technology. Inc.
Stella McDonald
Abderrahmane Touati
Francis Rob Delafield
Steve Terll
Denise Aslett
Ahmed Abdel-Hady
Mariela Monge
Wendy Coss
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Table of Contents
Disclaimer i
Table of Contents iv
List of Figures v
List of Tables i
Acronyms and Abbreviations iii
Executive Summary v
Introduction 1
1.0 Project Description 1
2.0 Materials and Methods 1
2.1 Indoor Material and Equipment Categories 1
2.1.1 Category 2 Materials 2
2.1.2 Category 3 Equipment 4
2.1.3 Category 4 Equipment 4
2.2 Environmental Control Chamber 5
2.3 PAA Fog and LCHPV Exposure Events 6
2.3.1 Overview of the PAA Fog Procedure 6
2.3.2 Overview of the LCHPV Exposure Procedure 7
2.3.3 Category 4 Equipment Exposure Preparation 8
2.3.4 PAA Fog and HPV Exposure Event Sequence 8
3.0 Sampling Approach 12
3.1 Aqueous Hydrogen Peroxide Analysis 12
3.2 HPV Monitoring 13
3.3 Temperature and RH Monitoring 13
3.4 Biological Indicators (Bis) 14
3.5 Electrostatic Discharge (ESD) Workstation 14
3.6 Visual Inspection 15
3.7 Functionality Testing 15
3.7.1 Category 3 Materials 15
3.7.2 Category 4 Materials 17
3.8 Location of Control Equipment 19
3.9 Representative Samples 19
3.10 Material and Equipment Storage and Preservation Methods 25
4.0 Results and Discussion 26
4.1 Exposure Test Matrix and Summary of Test Conditions 26
4.1.1 PAA Fog Test 28
iv
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4.1.2 3% LCHP Test 28
4.1.3 8% LCHP Test 29
4.2 Visual Inspections 30
4.2.1 Category 2 Materials 30
4.2.2 Category 3 Equipment 35
4.2.3 Category 4 Equipment 36
4.3 Functionality Assessments 41
4.3.1 Categories 2 and 3 Equipment 41
4.3.2 Category 4 Materials Functionality Assessment 41
4.4 Decontaminant Effectiveness 55
5.0 Quality Control/ Quality Assurance 55
5.1 Sampling, Monitoring, and Equipment Calibration 55
5.2 Acceptance Criteria for Critical Measurements 56
5.3 Data Quality 56
6.0 Summary and Conclusions 57
6.1 PAA Fog Exposure 57
6.2 LCHPV generated with 3% HP 58
6.3 LCHPV generated with 8% HP 58
6.4 Summary of impacts on personal computers 59
7.0 References 60
Appendix A 62
Appendix B 64
List of Figures
Figure 2-1. Fogger used to disperse PAA 6
Figure 2-2. Honeywell HCM-6009 humidifier 7
Figure 2-3. 5 Biological indicators (circled in red) and 1 HOBO® logger (circled in yellow)
positioned inside the central processing unit chassis 8
Figure 2-4. General setup of Categories 2, 3, and 4 materials and equipment for PAA fog and
HPV exposure. Photo a: Category 4 equipment; Photos b, c, and d were
Categories 2,3, and 4 materials and personal electronics 10
Figure 2-5. Placement of test materials, humidifier, and mixing fan inside the COMMANDER (a)
facing the back wall and (b) facing the entrance 11
Figure 3-1 PC Doctor Service Center™ system tests and test identification codes 18
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Figure 3-2. Category 2 metal coupon controls (a) 3003 aluminum, (b) 101 copper, (c) low-carbon
steel, (d) 316 stainless steel, (e) 304 stainless steel, (f) 410 stainless steel, (g) 430
stainless steel, and (h) 309 stainless steel 20
Figure 3-3. Category 2 material controls (a) DSL line conditioner, (b) switch (incandescent light),
(c) steel outlet/switch box, (d) silicone caulk (circled in yellow), (e) yellow SJTO 300
VAC service cord, (f) smoke detector (cover removed), (g) laser-printed paper, (h)
ink Jet colored paper, and (i) a color photograph 21
Figure 3-3. Category 2 plastic material controls: (a) low-density polyethylene, (b) HDPE plastic
film, (c) duct tape, (d) acrylonitrile butadiene styrene plastic, and (e) PVC plastic 22
Figure 3-4. Category 3 equipment controls: (a) mobile phone, (b) printer/fax/scanner/copier
machine, (c) data CD, (d) data DVD, (e) USB flash drive, and (f) SD memory card 23
Figure 3-5. Category 4 equipment controls: (a) front external tower components (front ports), (b)
monitor, (c) keyboard, (d) mouse, (e) internal tower components, and (f) rear
external tower components 24
Figure 4-1. HPV concentration during PAA fog test 28
Figure 4-2. HPV concentration during 3% LCHP test 29
Figure 4-3. HPV concentration during 8% LCHP test 30
Figure 4-4. Copper coupons at month 12 after: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8%
LCHP exposures 33
Figure 4-5. Low carbon steel at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and
(d) 8% LCHP solutions 33
Figure 4-6. Type 304 stainless steel coupons at 12-months post-exposure: (a) control, (b) PAA,
(c) 3% LCHP, and (d) 8% LCHP solutions 33
Figure 4-7. Aluminum at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d)
8% LCHP solutions 34
Figure 4-8. Switch box at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d)
8% LCHP solutions 34
Figure 4-9. Light with switch at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and
(d) 8% LCHP solutions 34
Figure 4-10. Inkjet-printed paper at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP,
and (d) 8% LCHP solutions 35
Figure 4-11. SD Cards at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d)
8% LCHP solutions 35
Figure 4-12. USBs at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8%
LCHP solutions 36
Figure 4-13. All-ln-One printers at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP,
and (d) 8% LCHP solutions 36
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Figure 4-14. Control desktop computer at month 12 of the observation period: (a) monitor, (b)
keyboard, (c) computer exterior, and (d) computer interior 37
Figure 4-15. T01 desktop computer 12 months after PAA exposure: (a) monitor, (b) keyboard, (c)
computer exterior, and (d) computer interior 38
Figure 4-16. T02 desktop computer 12-months after 3% LCHP exposure: (a) monitor, (b)
keyboard, (c) computer exterior, and (d) computer interior 39
Figure 4-17. T03 desktop computer 12-months after 8% LCHP exposure: (a) monitor, (b)
keyboard, (c) computer exterior, and (d) computer interior 40
Figure A-1. COMMANDER Piping and Instrumentation 63
Figure B-1. Condensation after Day 6 of preliminary test (a) next to the humidifier, (b) on the
COMMANDER floor and, (c) on the COMMANDER walls 66
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List of Tables
Table 2-1. Category 2 Materials 3
Table 2-2. Category 3 Materials 4
Table 2-3. Category 4 Materials 5
Table 3-1. Monitoring Methods 12
Table 3-2. HP Based Fogging Solutions 13
Table 3-3. RH and Temperature Sensor Specifications 13
Table 3-4. Assessment Criteria for Categories 2 and 3 Equipment 15
Table 4-1. Test Matrix 26
Table 4-2. Summary of Test Conditions During Dissemination 27
Table 4-3. Summary of Visually-Observed Changes for Impacted Category 2 Materials 32
Table 4-4. Summary of Visually-Observed Changes for Category 3 Equipment 35
Table 4-5. Summary of Visually-Observed Changes in Category 4 Materials 37
Table 4-6. Functionality Issues Found for Category 2 and 3 Equipment 41
Table 4-7. Summary of Failed Tests and Corresponding Subsystems for the Category 4 Control
Set 43
Table 4-8. PC-Doctor™ Scores and Failed Test IDs for PC-01 (Control) 43
Table 4-9. PC-Doctor™ Scores and Failed Test IDs for PC-02 (Control) 44
Table 4-10. PC-Doctor™ Scores and Test Failure IDs PC-03 (Control) 44
Table 4-11. Summary of Failed Tests and Corresponding Subsystems for the PAA Fog Test
Category 4 Set 46
Table 4-12. PC-Doctor™ Scores and Failed Tests for PC-04 (PAA) 46
Table 4-13. PC-Doctor™ Scores and System Failures for PC-05 (PAA) 47
Table 4-14. Monthly PC-Doctor™ Scores and System Failures for PC-06 (PAA) 47
Table 4-15. Summary of Failed Tests and Corresponding Subsystems for the Category 4 3%
LCHP Test Set 49
Table 4-16. Monthly PC-Doctor™ Scores and System Failures for PC-07 (3% LCHP) 49
Table 4-17. Monthly PC-Doctor™ Scores and System Failures for PC-08 (3% LCHP) 50
Table 4-18. Monthly PC-Doctor™ Scores and System Failures for PC-09 (3% LCHP) 50
Table 4-19. Summary of Failed Tests and Corresponding Subsystems for the Category 4 8%
LCHP Test Set 52
Table 4-20. Monthly PC-Doctor™ Scores and System Failures for PC-10 (8% LCHP) 52
Table 4-21. Monthly PC-Doctor™ Scores and System Failures for PC-11 (8% LCHP) 53
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Table 4-22. Monthly PC-Doctor™ Scores and System Failures for PC-12 (8% LCHP) 54
Table 4-23. Inactivated Biological Indicator (Bis) for Each Location 55
Table 5-1. Sampling and Monitoring Equipment Calibration Frequency 56
Table 5-2. Analysis Equipment Calibration Frequency 56
Table 5-3. QA/QC Acceptance Criteria for Critical Measurements 56
Table 5-4. Precision (RSD) and Accuracy (% Bias) Assessments of the ATI HP Gas Sensor 57
Table 5-5. Precision (RSD) and Accuracy (% Bias) Assessments of the Vaisala Transmitter's RH
Sensor 57
Table 6-1. Number of Second-Trial Failures on Personal Computers 569
Table B-1. Total and Average Water Disseminated by COTS Humidifier Over 6 Day Period 65
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Acronyms and Abbreviations
ATI Analytical Technology, Inc.
Bl biological indicator
CD compact disc
CESER Center for Environmental Solutions and Emergency Response
COMMANDER Consequence Management and Decontamination Evaluation Room
COTS commercial off-the-shelf
CFL compact fluorescent Light
DSL digital subscriber line
DVD digital versatile disc
EPA U.S. Environmental Protection Agency
ESD electrostatic discharge
HDPE high-density polyethylene
HEPA high-efficiency particulate air filter
HP hydrogen peroxide
HPV hydrogen peroxide vapor
hr hour
L liter
LCHP low concentration hydrogen peroxide
LCHPV low concentration hydrogen peroxide vapor
LDPE low-density polyethylene
m meters
min minute
mL milliliter
NIST National Institute of Standards and Technology
ORD Office of Research and Development
PAA peracetic acid
PC personal computer
pDAQ personal data acquisition
PEL permissible exposure limit
ppm parts per million
PVC polyvinyl chloride
QA quality assurance
QC quality control
RSD relative standard deviation
RH relative humidity
ROM read-only memory
RW rewritable
SCADA supervisory control and data acquisition
SD secure digital
TSA tryptic soy agar
UPS uninterruptable power supply
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USB universal serial bus
w/w weight/weight
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Executive Summary
The U.S. Environmental Protection Agency (EPA) and others have evaluated and demonstrated
numerous decontamination techniques that can be used effectively to inactivate Bacillus anthracis (B.
anthracis, the causative agent for anthrax) spores on a wide variety of materials and in different
environments. In addition to efficacy, other criteria such as material compatibility, may be used to
select which decontaminant to employ in the event of a B. anthracis contamination incident. The
fogging of peracetic acid (PAA) has been shown to be an effective decontaminant against B. anthracis
spores. Similarly, the generation of low concentrations of hydrogen peroxide vapor (LCHPV) by
vaporizing either 3% or 8% aqueous hydrogen peroxide solutions in off-the-shelf humidifiers, is also an
effective decontamination technique. These decontamination approaches are effective as well as
relatively simple to use, although the detrimental effects they may have on various types of materials
and equipment are unclear.
Thus, the purpose of this study was to determine the impacts of PAA fog and LCHPV on representative
indoor materials and electronic equipment. This effort examined the impact of each decontaminant on
the physical appearance and functionality of various materials and electronic equipment. Visual
assessments and functionality inspections of equipment were performed before and after exposure to
each decontaminant over a 12-month post-exposure observation period. During the fogging of PAA and
the generation of LCHPV, Geobacillus stearothermophilus biological indicators (B. anthracis surrogates)
were used to ensure the decontaminants were effective in inactivating bacterial spores.
The decontaminants' impacts were evaluated against three categories of materials. These materials
included coupons (excised samples) of metal and plastic materials; small electrical items or electronics
such as a light switch, smoke detector, mobile phone, and USB flash drive; and computers and related
peripheral equipment.
The fogging of PAA solution caused visually-observed appearance changes (e.g., discoloration, oxidation,
residue) on the copper, low-carbon steel, 304 stainless steel, and aluminum metal coupons. Some
minor corrosion and/or residue was also observed on the electrical switch box, incandescent light, and
the smoke detector battery terminals. For the computers, the external, non-metal surfaces had a
moderate amount of white, powdery residue. Internal and external metal surfaces showed small amounts
of rusting and a significant amount of white residue. Some functionality incompatibilities with the PAA
fog included issues with the power button on the mobile phone and the smoke detector giving a false
"low battery" alert. For the computers, there were a total of six subsystem test failures that were not
observed in the control set of computers; four were related to the +- rewrite (RW) drive and two related
to the read-only memory (ROM) drive.
For the LCHPV exposure generated from the 3% aqueous hydrogen peroxide solution, there were
minimal compatibility issues with the materials and equipment. Visually-detected appearance changes
were limited to the low-carbon steel, which showed some minor oxidation. The exposure did not affect
the functionality of any equipment, except for a few issues with computers. Four unique subsystem test
failures, not observed in the control computer set, were observed, and all were related to the +-RW
drive.
V
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For the LCHPV exposure generated using the 8% HP solution, there were minimal compatibility issues as
well. As with the LCHPV exposure with 3% HP solution, visually-observed changes in material and
equipment were observed on low-carbon steel which, as before, showed rust on exposed surfaces. The
exposure did not affect the functionality of equipment. Three unique subsystem test failures, not
observed with the control computers, were observed in the exposed computers and included minor
issues with the sound card, +-RW drive, and universal serial bus (USB).
For all three decontaminants evaluated, all biological indicators were inactivated.
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Introduction
The U.S. Environmental Protection Agency (EPA) and others have evaluated and demonstrated
numerous decontamination techniques that can be used effectively to inactivate Bacillus anthracis (B.
anthracis, the causative agent for anthrax) spores on a wide variety of materials and in different
environments. In addition to efficacy, other criteria such as material compatibility, may be used to
select which decontaminant to use in the event of a B. anthracis contamination incident (Wood et al.,
2019). The fogging of peracetic acid (PAA) has been shown to be an effective decontaminant against B.
anthracis spores (Richter et al., 2018; Wood et al., 2013). Similarly, the generation of low
concentrations of hydrogen peroxide vapor (LCHPV) via the vaporization of 3% or 8% aqueous hydrogen
peroxide (HP) solutions in off-the-shelf humidifiers, is also an effective decontamination technique
(Wood, et al., 2016; Mickelsen et al., 2019). These decontamination techniques are effective as well as
relatively simple to use, although their impact on various types of materials and equipment is unclear.
1.0 Project Description
The purpose of this study was to determine the impacts of PAA fog and LCHPV on representative indoor
materials and electronic equipment. This effort examined the impact of each decontaminant on the
physical appearance and functionality of materials and electronic equipment.
Visual assessments and functionality inspections of equipment were performed before and after
exposure to each decontaminant over a 12-month post-exposure observation period. Visual
assessments were performed at a 1-, 3-, 6- and 12-months post-exposure. Functionality assessments
were completed once per month for 12-months after exposure. All tests were conducted at the U.S. EPA
facility located in Research Triangle Park, NC.
The study described in this report builds on and is consistent with previous other U.S. EPA studies to
examine the material compatibility of decontaminants (Adrion, et al., 2019; U.S. EPA, 2010; U.S. EPA
2017a; U.S. EPA 2012; U.S.EPA, 2014).
2.0 Materials and Methods
2.1 Indoor Material and Equipment Categories
The decontaminants' impacts were evaluated against three categories of materials.
In general, Category 2 materials are representative of materials that may be present in limited amounts
in indoor areas. Category 3 materials are representative of personal electronic equipment that are
typical of a commercial or government office setting. Category 4 materials were chosen to be
representative not only of computers typical of commercial/ government use, but also as a collection of
subsystems representative of a broad range of technological equipment, from printed circuit boards to
optical devices to fan bearings. Note that Category 1 materials, such as those used for building
structures, were evaluated in previous material compatibility assessment, but were not included in this
assessment. Most of the EPA material compatibility assessments have excluded structural materials
(Adrion et al. 2019). Further details on each category of materials is discussed below.
1
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2.1.1 Category 2 Materials
Category 2 materials include those that are likely to be used in limited amounts as building materials or
electronic equipment components. Specifically, Category 2 materials are of small surface area within a
building, have a minimal fumigant material demand, and have functionality and use that could be
impacted by the decontaminant exposures. Table 2-1 provides a description of the Category 2 materials.
The visual inspections were directed toward areas where corrosion or material changes are expected
from the decontamination treatment. Printed documents and pictures were inspected for possible
changes in the appearance (color and legibility) and the integrity of the paper. Inspections occurred
monthly over a 12-month observation period, with materials stored at ambient conditions in an
environmentally controlled facility throughout the observation period. Visual inspections included digital
photography to document the appearance of each material before and after each decontamination
event.
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Table 2-1. Category 2 Materials
Material
Description
Supplier/
Manufacturer
Part No.
Coupon Size and/or No.
of replicates for each test
1100 Aluminum
Corrosion-resistant,
Textured 0.063 inch thick
sheet
McMaster Carr
88685K93
2x2 inches, 3 coupons
Super-conductive 101
0.063 inch thick, 1/8 Hard
McMaster Carr
89675K751
2x2 inches, 3 coupons
copper
Temper
Low-carbon steel
0.0625 inch thick
McMaster Carr
6544K53
VA x 2 inches, 3 coupons
Type 316 stainless steel
Highly-corrosion resistant,
0.063 inch thick
McMaster Carr
9090K1
1x2 inches, 3 coupons
Type 304 stainless steel
Brushed, 0.0625 inch
thick, #3 finish
McMaster Carr
9085K1
1x2 inches, 3 coupons
Type 410 stainless steel
Tight-tolerance, wear-
resistant, 0.063 inch thick
McMaster Carr
9524K69
2x2 inches, 3 coupons
Type 430 stainless steel
0.025 inch thick
McMaster Carr
1294T33
2x2 inches, 3 coupons
Type 309 stainless steel
High-temperature, 0.25
inch thick
McMaster Carr
9205K15
1x2 inches, 3 coupons
Digital subscriber line
Telephone and DSL
McMaster Carr
1522T23
1 replicate
(DSL) line conditioner
connectors embedded
within
Portable light
With electrical switch
McMaster Carr
1627K12
1 replicate
Steel outlet/switch box
2x3x1% inches
McMaster Carr
71695K81
1 replicate
Silicone caulk
Mildew-resistant sealant
McMaster Carr
7582T15
lxl inch
Yellow SJTO 300 VAC
16/3 American wire
McMaster Carr
8169K32
3 replicates
service cord
gauge, 0.33 inch outer
diameter
Smoke detector
Battery-powered
ionization sensor with
battery
First Alert
SA304
1 replicate
Laser-printed paper
Stack of 15 color printed
pages
RTO-H206- HP
4730 Color
LaserJet
NA
8A x 11 inches
Ink Jet colored paper
Stack of 15 color printed
pages (see Appendix B)
HP DeskJet
932C
NA
8% x 11 inches
Color photograph
4x6 inches, Kodak
processing
Walgreens
NA
4x6 inches, 3 replicates
Static intercept bags
20 x 24 x 0.003 inches
Dasal Technical
Products
NA
1 replicate
Acrylonitrile butadiene
0.125 inch thick, beige
McMaster Carr
8586K101
VA x 2 inches, 3 replicates
styrene plastic
HDPE plastic film
4 mil HDPE stretched
across PVC tube
McMaster Carr
86255K61
2x4 inches, 3 replicates
LDPE plastic film
4 mil LDPE stretched
across PVC tube
McMaster Carr
8553K814
2x4 inches, 3 replicates
Duct tape
2 inch wide, premium
duty, Fed. Spec. PPP-T-
60E, Type IV, Class 1, used
to seal plastic films onto
PVC tube
McMaster Carr
7612A7
1 inch long, 3 replicates
PVC plastic
High-strength PVC sheet
McMaster Carr
87025K116
1 inch length, 3 replicates
HDPE: high-density polyethylene, LDPE: low-density polyethylene, No.: number
3
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2.1.2 Category 3 Equipment
Category 3 equipment included small personal electronic equipment. As with Category 2 materials,
changes in appearance and functionality of the equipment were monitored over the 12-month
observation period. The exposure impact assessment involved visual inspections for aesthetic effects
and documentation with digital photographs. Functionality evaluations were performed by operating
the equipment as intended by the manufacturer. The ability to successfully complete the desired
operation and notable changes in the production quality were assessed by comparison to similar,
unexposed equipment. Table 2-2 lists the Category 3 equipment.
Table 2-2. Category 3 Materials
Equipment
Description
Manufacturer or
Supplier
Model or Item No.
No. of
replicates per
test
Mobile phone
ZTE Maven 3
ZTE
Z835
1
Fax/phone/copier
Color Inkjet All-in-One Printer
Brother
MFCJ497DW
1
machine
with Mobile Device and Duplex
Printing
Data CD
Best of the Most Relaxing
Classical Music in the Universe,
Music CD
Walmart Inc.
Walmart,
000873479
1
Data DVD
The Lord of The Rings: The Two
Towers, (2002) Standard DVD
video
Walmart Inc.
Walmart,
0088392945298
1
USB flash drive
4GB flash drive
SanDisk
S DCZ36-004G-A11
1
CD: compact disc, DVD: digital video disc, No.: number, SD: Secure digital, USB: universal serial bus
2.1.3 Category 4 Equipment
Category 4 equipment included desktop computers and ancillary equipment. The objective for this
category of equipment (and materials) was to assess the impact of the test conditions using visual
inspection, functionality testing, and a personal computer (PC) diagnostic tool (PC-Doctor Service
Center™ 11 software). Components and specific parts of components susceptible to corrosion due to
the decontamination process were assessed. This information could be used to make informed decisions
about the compatibility of other equipment that has similar components (at least similar in operation or
material makeup) to reduce further testing and uncertainty in a field application. Table 2-3 lists the
Category 4 equipment.
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Table 2-3. Category 4 Materials
Equipment
Description
Manufacturer
Item No.
No. of replicates per
test
Personal Computer
Dell Precision Tower
3620 XCTO base
Dell
210-ALFI
3
Monitor
Dell 19" Monitor-
E1916H
Dell
210-AGND
3
Mouse
Dell MS 116 Wired
Mouse
Dell
275-BBBW
3
Keyboard
Dell KB216 Wired
Multi-Media
Keyboard - English
Dell
580-ADJC
3
2.2 Environmental Control Chamber
All decontamination tests were conducted in, and materials placed within, the Consequence
Management and Decontamination Evaluation Room (COMMANDER). COMMANDER consists of a
stainless steel-lined inner chamber built specifically for decontamination testing, with internal
dimensions of approximately 2.4 meter (m) wide, 2.5 m deep, and 2.8 m high. At the entrance to the
chamber is an airlock compartment, and enclosing the chamber and airlock is an exterior steel shell.
When desired, all three components can be kept under cascading slightly negative pressure (with the
greatest negative pressure in the inner chamber) by using separate air streams with valve controls on
the inlet and outlet of each component. Air entering the decontamination chamber passes through a
high-efficiency particulate air (HEPA) filter, and exhaust air from the chamber is ducted to an activated
carbon bed and HEPA filter prior to being released into the facility exhaust system. Fans were used
inside the chamber to provide internal mixing during fogging. The inner chamber inlet and outlet ducts
were closed and fans turned off during fogging activities (Wood et al., 2013). A piping and
instrumentation diagram of COMMANDER can be found in Appendix A.
Temperature (T), relative humidity (RH), air pressures, and flow rates within the decontamination
chamber are controlled and/or their data logged continuously using a supervisory control and data
acquisition (SCADA) system. Temperature and RH within the chamber were measured using a
temperature and RH transmitter (model HMD40Y, Vaisala Inc., Helsinki, Finland). This instrument was
calibrated prior to each test by comparing its RH data with known RH values generated in the sealed
headspace above individual saturated solutions of various salt compounds. The RH meters were
replaced if calibration criteria could not be met. During dissemination of the PAA and HP solutions and
subsequent dwell time, the RH and temperature within the chamber were monitored, but not
controlled. (All tests were conducted at lab ambient temperatures of approximately 72 °F.) This
approach to not controlling RH is consistent with previous studies using foggers or humidifiers for
decontamination (Richter et al., 2018; Wood et al., 2013; Wood, et al., 2016; Mickelsen et al., 2019).
Typically, maximum RH measurements for the LCHPV exposures using a commercial off-the-shelf (COTS)
humidifier neared or exceeded the maximum range of the RH meter during the fogging events.
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2.3 PAA Fog and LCHPV Exposure Events
2.3.1 Overview of the PAA Fog Procedure
PAA fog was produced using a Sarii-Tizer™ ultra-low volume fogger (Curtis Dyna-fog, Ltd., Westfield, IN).
The fogger consisted of a motor/blower assembly, nozzle system, nozzle housing, 1-gallon formulation
tank, and metering a valve. The PAA solution (MinnCare Cold Sterilant, Mar Cor Purification, Lowell,
MA; EPA Registration Number 52252-4) was drawn from the formulation tank through the control valve
and into the nozzle system where it was pneumatically sheared into an aerosol or mist with a mean
droplet size of 31.0 |im. The droplets were then disseminated throughout the chamber by ambient air
passing through the nozzle system. The fogger is shown in Figure 2-1.
Figure 2-1. Fogger used to disperse PAA.
From a previous study (U.S. EPA, 2016), it was determined that fogging 31.25 milliliter (mL) PAA per m3
of volume to be decontaminated was the minimum amount required for effective decontamination
against B. anthracis spores. Based on this amount and the volume of COMMANDER, a volume of 750 ml
of PAA solution was fogged. The fogger was transferred to COMMANDER and placed on the floor in
front of the chamber door, facing the back wall with the nozzle positioned at an angle of approximately
70°. The metering valve knob was positioned on the low flow setting which allows for reduced droplet
size. The fogger was plugged into an unenergized power outlet and the fogger's power switch placed in
the ON position. A 12-inch (in), 3 speed, oscillating fan (Pelonis Technologies Inc., Exton, PA) was placed
in COMMANDER with the speed setting set to the HIGH position in order to promote even fog
distribution throughout the chamber. The COMMANDER chamber was sealed and an approximate zero
air exchange rate was set by adjusting the chamber's air supply and exhaust valves. The fogger was
activated remotely using the SCADA system. Active fogging is defined for this report as the duration of
time the unit generated fog output, continued until the volume of solution in the fogger tank was
insufficient to support fog production. The fogger was remotely turned off and the chamber allowed to
dwell overnight, consistent with a previous study in which PAA was fogged and shown to be effective for
B. anthracis (U.S. EPA 2016). At the start of the following day, the chamber was aerated. The materials
and equipment were collected for photo documentation and evaluation. The remaining solution in each
fogger was transferred to a graduated cylinder and measured. The volume of solution dispersed as fog
was determined volumetrically.
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2.3.2 Overview of the LCHPV Exposure Procedure
The two LCHPV tests were performed using the Honeywell QuietCare Cool Mist Console Humidifier,
HCM-6009 (Honeywell, Morristown, NJ). The humidifier was a cool mist evaporative humidifier that
used a small fan to pull air through a wicking filter saturated with aqueous solution from the reservoir to
disperse. Each humidifier had two 1 >2 gallon tanks for a total capacity of 3 gallons with 9 possible
combinations of output settings. Figure 2-2 shows the Honeywell, HCM-6009 humidifier.
V
Figure 2-2. Honeywell HCM-6009 humidifier.
LCHPV was produced from prepared solutions of 3% weight/weight (w/w) and 8% (w/w) HP solution
using a 35% HP aqueous stock solution (Hi Valley Chemical, Inc., Centerville, UT). The HP concentration
in solution of both the stock and prepared solutions were measured using the analysis method detailed
in Section 3.1. The temperature and pH of the prepared HP solutions were measured using the
procedure outlined in Section 3.2. The total required volume of prepared HP solution, 4 liter (L) of 3% HP
and 3 L of 8% HP, was determined based on a previous study (U.S. EPA, 2017b). The HP solution was
divided evenly between the two humidifier tanks and the humidifier weight was obtained. The output
settings used for this investigation were the lowest fan setting (the single blade icon) and the highest
humidistat setting (the 4-drop icon). As with the fogger, the humidifier was plugged into an unenergized
power outlet and the humidifier settings adjusted to the appropriate configuration. A 12-inch oscillating
fan was placed in the COMMANDER with the speed setting set on HIGH to promote even mixing during
the exposure. COMMANDER was sealed and an approximate zero air exchange rate was maintained by
adjusting the chamber's air supply and exhaust valves. The humidifier was activated remotely using the
SCADA system. Vapor production continued until the humidifier's internal floating switch deactivated
the unit. The HPV concentration was allowed to passively fail below the permissible exposure limit (PEL)
prior to re-entry. The total exposure time was approximately 3 days for the LCHPV using 3% HP solution
and 2.5 days for the LCHPV exposure with 8% solution, consistent with previous studies (Wood et al.,
2016; Mickelsen et al., 2019) The humidifier was then removed from the chamber and the final weight
recorded. The remaining solution in each tank and the reservoir was combined in a graduated cylinder
and measured. Due the significant portion of the residual test solution that remained in the wicking
filter, the volume of solution remaining in the wick was determined gravimetrically.
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2.3.3 Category 4 Equipment Exposure Preparation
Prior to exposure, Category 4 computer operation systems were configured for PC-Doctor Service
Center™ 11 software (PC Doctor, Reno, NV), and a burn-in-test protocol hardware/software diagnostic
program (PassMark, Sydney, Australia). Each computer was assessed with PC-Doctor™ software to
establish pre-exposure baselines for the computer subsystems detailed in Section 3.7.2. Installed burn-
in-test software was programmed to imitate typical office use during a work week (i.e., on and active 5
days per week, 8 hours per day) during exposure and the 12-month observation period following
exposure.
A HOBO® RH/temperature logger and five Geobacillus stearothermophilus biological indicators (Bis)
(Mesa Laboratories, Inc, Bozeman, MT) were mounted in each computer chassis. The HOBO® logger
recorded real-time internal temperature and RH data from inside the functioning computer during the
exposure (active fogging or humidifying and dwell). The tower chassis were closed during each
exposure.
The exposed Bis were processed in the microbiological laboratory for qualitative spore viability. Figure
2-3 shows the placement of the Bis (circled in red) and the HOBO® logger (circled in yellow) inside each.
Figure 2-3.5 Biological indicators (circled in red) and 1 HOBO® logger (circled in yellow) positioned inside the
central processing unit chassis.
Category 4 equipment was ON and executing a PassMark burn-in-test session during the exposure. All
other electronic equipment, with the exception of the light switch, were powered ON during each
exposure.
2.3.4 PAA Fog and HPV Exposure Event Sequence
The piping and instrumentation of the control chamber is in Appendix A. The general procedure for each
exposure is as follows:
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1. Within 1 week of fogging or humidifying the decontaminant, a hydrogen peroxide vapor (HPV)
sensor (Section 3.3), and a temperature and humidity probe (Section 3.4) were calibrated.
2. Test facilities were prepared with two electrostatic discharge (ESD) workstations for computer
work and/or storage (Section 3.5). An onsite laboratory was outfitted with a permanent ESD
workstation that was used for long-term computer storage and monthly evaluations. A
temporary workstation was assembled inside of the COMMANDER chamber and was used for
staging the computers during fog and vapor exposures.
3. Category 4 computers were assembled, configured, and photographed at the permanent ESD
workstation located onsite in Highbay Building Room 106. Baseline functionality testing was
completed using PC Doctor Inc.'s PC-Doctor Service Center 11 software. Computers were
disassembled, packaged in 4 mil Static Intercept® bags (Xtend Packaging, Inc., Houston, TX),
transported on a grounded steel conductive cart (McMaster Carr®, Santa Fe Springs, CA), then
reassembled on the temporary ESD workstation located inside of the exposure chamber.
Categories 2 and 3 materials underwent baseline testing and photography, were transported to
the exposure chamber, then staged as shown in Figure 2-4.
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(a)
(b)
4. Figure 2-4. General setup of Categories 2, 3, arid 4 materials and equipment for PAA fog and
HPV exposure. Photo a: Category 4 equipment; Photos b; c, and d were Categories 2,3, and 4
materials and personal electronics. Three computers designated as controls for Category 4
remained at the permanent ESD workstation. The control materials and equipment for
Categories 2 and 3 remained in the same onsite laboratory as the permanent ESD workstation
for long-term storage during the observation period.
5. Five Bis and 1 HOBO logger were placed outside of COMMANDER in the enclosure area for use
as controls (unexposed to the treatment conditions).
6. The fogger or humidifier containing prepared aqueous decontaminant solutions were placed
inside the COMMANDER. Figure 2-5 shows the humidifier and fan placement during testing.
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Figure 2-5. Placement of test materials, humidifier, and mixing fan inside the COMMANDER (a) facing the
back wall and (b) facing the entrance.
7. The COMMANDER chamber was sealed and decontamination initiated. The foggers or
humidifiers operated for the minimum time required to empty the tanks before being remotely
deactivated. After the conclusion, the chamber was allowed to dwell for the time required for
the HPV to naturally decompose to levels below the permissible exposure limit (PEL). After the
contact time was reached, aeration of the chamber was started.
8. When the chamber was verified safe for entry, Category 4 materials were repackaged in the
static intercept bags and the Categories 2 and 3 materials returned to trays.
9. All materials were transported on the grounded cart to the anti-static workstation for a series
of monthly post-exposure functionality assessments and visual observations. Foggers or
humidifiers were removed, humidifiers weighed, and the remaining solution in the foggers
collected and measured.
10. The Bis were collected and relinquished to the microbiological laboratory for qualitative
analysis. The HOBO loggers were removed, and the digital data files saved on EPA servers.
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3.0 Sampling Approach
Prior to dissemination of PAA or HPV, the active ingredient concentration of the test solution was tested
using the measurement procedures described in Section 3.1. During exposure, chamber HPV
measurements were collected in real time using an Analytical Technology, Inc. (ATI) B-12 series
transmitter for HPV (p/n B12-11-6-0100-1, Analytical Technology Inc., Collegeville, PA) that was
positioned in the center of the chamber.
The testing strategy for the impact of the decontamination processes on material and electronic
equipment requires monitoring the environment in COMMANDER and inside the computers for the
testing of Category 4 equipment. The sampling locations of the temperature and RH loggers (HOBO®
data logger, p/n U10-003, Onset Computer Corp., Bourne, MA) inside the computers were consistent
among test runs to avoid measurement bias.
Table 3-1 provides information on the monitoring method, test location, scope, and frequency for the
measurement techniques needed for this material compatibility study.
Table 3-1. Monitoring Methods
Monitoring Method
Scope
Frequency/Duration
Visual Inspection
Effects of fogging PAA or HPV
Monthly
RH/temperature sensor
0 to 100% RH, -20 to 80 °C
Real time/6 per minute
PC-Doctor Service Center 11 (PC Doctor
Inc.) diagnostic software
Computer functionality and hardware
compatibility
Monthly
Category 3 functionality testing
Basic functionality of Category 3
materials
Monthly
HPV: hydrogen peroxide vapor, PAA: peracetic acid, RH: relative humidity, RH: relative humidity
3.1 Aqueous Hydrogen Peroxide Analysis
Minncare® Cold Sterilant was used, undiluted, as the PAA fog test solution and a stock of 35% aqueous
hydrogen peroxide (HP) was used to prepare 3% and 8% aqueous HP solutions for the LCHPV tests. Both
stock solutions were received within four months of use and were stored, unopened in an
environmentally controlled laboratory.
For the PAA fog test, hydrogen peroxide vapor (HPV) was monitored as a surrogate indicator for PAA.
From the Minncare® EPA product label, the solution contains 4.5% PAA and 22.0% HP; an approximate
1:5 ratio. (Peracetic acid is manufactured and sold in a solution with hydrogen peroxide and acetic acid.
In this report as well as the literature, PAA always refers to this solution mixture. This approach to
measuring HPV to indicate presence of PAA in vapor is recommended in the Minncare EPA registration
label. We also note that the EPA label for Minncare allows for fogging applications, and does not
recommend controlling RH.)
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Prior to testing, the HP concentrations in both the PAA solution and the 35% stock solution were verified
using an internal operating procedure summarized as follows: by transferring 5 grams (g) of PAA was
transferred to a 250-milliliter (mL) flask then, 40 mL of H2S04 and 150 mL of deionized water added.
The sample was titrated to permanent pink with 1 Normal (N) KMn04. The volume of KMn04 is used to
calculate the percent HP (w/w). The accuracy criterion for the measured HP concentration in solution
was ± 10% of the manufacturer label for the stock solution and ± 10% of the calculated value for the
prepared solution.
The type, volume, and concentration of the test used for fogging were some of the independent
variables for this investigation. The solutions used for this effort are detailed in Table 3-2.
Table 3-2. HP Based Fogging Solutions
Test Solution
Active Ingredient
Minncare'R) Cold Sterilant
4.5% Peracetic acid, 22.0% hydrogen peroxide
HP solutions
3% and 8% solutions prepared from 35% stock solution
3.2 HPV Monitoring
Two electrochemical HPV sensors were used for this investigation: a sensor capable of detecting 0-1000
parts-per-million (ppm) HPV (Analytical Technology, Inc. [ATI] Model B12-34-1-1000-1, Collegeville, PA)
used during fogging of PAA and a sensor ranged 0-100 ppm HPV (Model B12-34-1-0100) for the LCHPV
exposures. The low-range transmitter was wired to an lotech 56 Series personal data acquisition (pDAQ)
module (Measurement Computing, Norton, MA) while the high-range was wired to the COMMANDER
SCADA system. Both had a variable output that was monitored in real time.
3.3 Temperature and RH Monitoring
During fogging of PAA or LCHPV exposures, real-time temperature and RH measurements were collected
using a Vaisala® model HMD53 temperature and RH transmitter. The Vaisala transmitter was placed
approximately 3 feet from the chamber walls inside the COMMANDER chamber. Repeated exposure to
fogging conditions degrades the transmitter. The RH sensor became corroded; the higher resistance
results in inaccurate RH readings. The Vaisala transmitter was calibrated before and after each
exposure. Damaged sensors were evaluated and replaced before each test.
Table 3-3. RH and Temperature Sensor Specifications
Instrument
Vaisala transmitter
HOBO Logger
RH Range
0 to 98%
25 to 95%
RH Accuracy-0 to 90%
+/- 3%
+/- 3.5%
RH Accuracy - 90 to 98%
+/- 5%
Unknown
RH Resolution
0.001%
0.07%
Temperature Range
-10 to 60 °C
-20 to 70 °C
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Temperature Accuracy
+/- 0.6 °C @ 20 °C
+/- 0.4 °C @ 25 °C
Temperature Resolution
0.001 °C
0.1 °C
3.4 Biological Indicators (Bis)
Bis were used to provide an assessment of decontamination efficacy, and were obtained from Apex
Discs (Mesa Labs, Bozeman, MT) loaded with nominally 1x10s Geobacillus stearothermophilus spores on
stainless steel disks in Tyvek™ (Dupont, Wilmington, DE) envelopes. The Bis provided a qualitative
result of growth or no growth after an incubation period of seven days, following exposure to the
decontaminant. The tube results were validated by plating the sample.
It was expected that the higher local temperatures inside the computer chassis would be associated
with lower RH values compared to the external, COMMANDER environment. Insufficient RH could
possibly result in a failure to achieve appropriate decontamination conditions inside the computer
chassis. Therefore, five Bis were placed on a table inside COMMANDER and five Bis were placed inside
each computer, for comparison. Thus, a total of 20 Bis were exposed to the decontaminant in each test.
Additionally, 5 Bis were placed just outside COMMANDER as positive controls. Upon completion of the
exposure test, the Bis were collected in a sterile sample bag and transferred to the Microbiology Lab for
processing.
During processing, each Bl was transferred aseptically from the Tyvek envelope to a sterile conical tube
containing 25 mL of nutrient broth. Positive and negative controls were processed in conjunction with
each test group for quality assurance. The tubes were incubated at 23 °C for seven days, and then
recorded as either "growth" or "no growth" based upon visual inspection. Tubes with growth turned the
nutrient broth a cloudy color and consistency. All tubes were plated on tryptic soy agar (TSA) to confirm
that any growth in the tube was indeed G. stearothermophilus and not contamination from another
organism. Using aseptic techniques, the TSA plates were incubated overnight at 32 °C. A visual
inspection of the plates was performed the following day to determine if the G. stearothermophilus had
grown; G. stearothermophilus grows leaving a reddish tint on the agar. Both positive and negative
controls were used to confirm G. stearothermophilus growth on TSA was consistent.
3.5 Electrostatic Discharge (ESD) Workstation
To prevent damage to electronic components that was unrelated to the treatment conditions,
precautions were taken to minimize static electricity while performing test activities. Precautions
included the use of two ESD workstations for computer work and/or storage: a permanent workstation
located in an onsite laboratory used for storage and monthly evaluations and, a temporary workstation
located inside the COMMANDER chamber used for staging the electronic equipment during fog and
vapor exposures. ESD workstations included static safety equipment such as an ESD work mat, an
electrostatic monitor, and ESD wrist bands. These sets of equipment worked in concert to dissipate
static electricity of the equipment and of the technician while handling the equipment; as well as to
prevent static electricity buildup in the workstation during the 12-month observation period. A second,
smaller sub-station was set up inside the COMMANDER for use during PAA fog and HPV exposures. All
computers were inspected, photographed, and operated on a certified ESD workstation. During
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operation, all computers were energized using surge protectors (BELKIN 7 Outlet Home/Office surge
protector with 6-foot cord, Part# BE107200-06; Belkin, Playa Vista, CA).
3.6 Visual Inspection
Visual inspection focused on the observed physical changes in the Categories 2, 3, and 4 materials and
equipment resulting from each decontaminant exposure event including changes in color and legibility
of print, and in material degradation resulting from corrosion or rust. Photo documentation of the
materials and equipment exposed to the decontaminant were taken prior to exposure to serve as the
baseline (along with materials and equipment not exposed to the decontaminant. Comparable digital
photographs were taken to document any changes that occurred over the 12-month period following
exposure. Time points documented include pre-exposure (baseline), 1-week, 3-months, 6-months, and
12-months post-exposure. Photo-documentation of the Category 4 computers was completed on the
permanent ESD workstation in Highbay Building Room 106.
Care was taken to avoid or minimize physical contact with surfaces to maintain the integrity of the
specimen over the duration of the 12-month observation period. Metal coupons (excised samples) were
staged and remained on a tray during exposure and throughout the observation period to minimize
physical manipulation. When handling the materials, powder-free nitrile exam gloves were donned for
Categories 2 and 3 materials and equipment and anti-static gloves were also donned for Category 4
equipment.
3.7 Functionality Testing
After exposure to the PAA fog or LCHPV, materials from all categories were tested for changes in
appearance and functionality over a 1-year observation period. After exposure to test conditions,
Category 3 equipment were tested for basic functionality and Category 4 personal computers were
tested using PC-Doctor Service Center 11 software (PC Doctor, Reno, NV, http://www.PC-Doctor.com).
All electronic equipment underwent functionality testing before and after exposure as did Category 2
materials as appropriate (e.g. incandescent light switch and smoke detector). Computers were set-up
and tested using procedures developed under a previous material compatibility study (U.S. EPA, 2010).
Category 2 material coupons and Category 4 computers were tested in triplicate. Category 3 equipment
were tested individually.
3.7.1 Category 3 Materials
Testing protocols were specific for each material and were intended to assess functionality by operating
the equipment as intended by the manufacturer. Table 3-4 details the assessments performed on
Category 2 and 3 materials and equipment.
Table 3-4. Assessment Criteria for Categories 2 and 3 Equipment
Material
Test Description
Tested with landline phone:
Pass - unit has verified dial tone and successful call.
DSL line conditioner
Fail - unit has unsuccessful dial tone and call or
successful call without a dial tone.
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Material
Test Description
Incandescent light
Tested with compact fluorescent light (CFL) bulb,
100-watt equivalent.
Pass - unit can be switched on and off as indicated
by the CFL
Fail - if the unit fails to switch CFL (and subsequently
a replacement bulb) on and off.
Smoke detector
Tested with smoke check spray.
Pass - Unit receives a pass if the audible alarm is
activated. Fail - Unit is assigned a fail if the alarm is
not activated after the first attempt and after
replacing the battery.
Ink Jet All-ln-One
Print, copy, fax, and scan functions tested and
assessed individually.
Pass-successful execution of all the above functions.
Fail - unsuccessful execution for any one of the above
functions resulted in a FAIL for the unit.
Mobile phone
Voice calls, text messages, and receiving data were
assessed individually.
Pass - successful execution of all the above
functions.
Fail - unsuccessful execution for any of the above
functions resulted in a FAIL for the unit.
Data CD
Audio functions were assessed by inserting CD into a
designated host computer and playing initial 10
second of each track.
Pass - the host computer successfully performed
seek and read functions; played first 10 seconds of
each track
Fail - host computer unable to complete seek and
read function
Data DVD
Audio and visually-observed performance was
assessed by inserting the DVD into a designated host
computer and playing the initial 10 seconds of each
scene.
Pass - the host computer successfully performed
seek and read functions; completed first 10 seconds
of each scene
Fail - host computer unable to complete seek and
read functions.
SD Memory Card
Device was inserted into a designated host
computer. Checks included ability to access the
external drive by navigating file explorer, open the
drive, and move documents to and from drive.
Pass - successful completion of the above checks.
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Material
Test Description
Fail - unsuccessful complete of the above checks.
USB Storage Device
Device was inserted into a designated host
computer. Checks included ability to access the
external drive by navigating file explorer, open the
drive, and move documents to and from drive.
Pass - successful completion of the above checks.
Fail - unsuccessful complete of the above checks.
3.7.2 Category 4 Materials
The protocol for the Category 4 equipment setup procedures was developed under a previous study
(U.S. EPA, 2010). Post-decontamination analysis on Category 4 equipment was performed monthly for a
duration of 12-months following exposure to test conditions. The computer systems were maintained in
the operational (ON) state and a burn-in-test sequence was performed five days a week, 8 hours per
day, to simulate real world working conditions.
PC-Doctor Service Center™ 11 software was commercially available software designed to diagnose and
detect computer component failures. For every monthly test, standard protocol for each test was
performed once. If any particular test failed the first time, the computer was retested a second time to
correct for possible human error(s). A test that failed the second time was labeled "Fail." If the test
failed the first time, but passes the second time, it was labeled "Pass2." For tabulation, a score of 1,000
is assigned to each "Fail," and a "Pass2" is assigned a score of 1. A "Pass" is assigned a score of 0. During
each pre- and post-exposure testing period, a total PC Doctor score was tallied for each computer based
on the number of tests that failed on the first or second attempt. Scores were evaluated only relative to
controls.
While the exact number and type of tests depends on the system being tested, for the case of the
Category 4 materials a total of 93 tests were run. A complete list of the PC Doctor Service Center™ 11
subsystem tests is shown in Figure 3-1.
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Test ID
Test Name
Realtek Audio
1
Rough Audio Test
2
Sound Interactive Test
OS-C:
3
Linear SeekTest
4
Linear Read Test
5
Random Seek Test
6
Funnel Seek Test
7
Targeted Read Test
8
Targeted Read Test - 2
9
SMART Status Test
10
SMART Thresh olds Test
11
SMART Short Self Test
12
SMART Extended Self Test
13
SMART Conveyance Self Test
HL-DT-ST DVD+-RW GHBON
14
DRAM Test
15
Flash ROMTest
16
Main ICTest
17
OPUTest
18
Spindle Test
19
Tray Out Test
20
Tray In Test
21
CD Linear SeekTest
22
CD Linear Read Compare Test
23
CD Random SeekTest
24
CD Funnel SeekTest
25
CD Read Performance Test
26
DVD LinearSeekTest
27
DVD Linear Read Compare Test
28
DVD Random Seek Test
Test ID
Test Name
29
DVD Funnel Seek Test
30
DVD Read Performance Test
HL-DT-ST DVD-ROM DH50N
31
DRAMTest
32
Flash ROMTest
33
Main IC Test
34
Spindle Test
35
Tray Out Test
36
Tray In Test
37
CD LinearSeekTest
38
CD Linear Read Compare Test
39
CD Random Seek Test
40
CD Funnel SeekTest
41
CD Read Performance Test
42
DVD LinearSeekTest
43
DVD Linear Read Compare Test
44
DVD Random SeekTest
45
DVD Funnel SeekTest
46
DVD Read Performance Test
HL-DT-ST DVD+-RW GHBON
47
CD Audio Test
48
CD LinearSeekTest
49
CD Linear Read Compare Test
50
CD Random Seek Test
51
CD Funnel Seek Test
52
CD Read Performance Test
HL-DT-ST DVD-ROM DH50N
53
CDAudioTest
54
CD LinearSeekTest
55
CD Linear Read Compare Test
56
CD Random SeekTest
Test ID
Test Name
57
CD Funnel Seek Test
58
CD Read Performance Test
HL-DT-ST DVD+-RW GHBON
59
CD-R Read Write Test
60
CD-RW Read Write Test
61
DVD-R Read Write Test
62
DVD-RW Read Write Test
63
DVD+R Read Write Test
64
DVD+RW Read Write Test
USB Drive M
65
Linear Read Test
USB Drive K
66
Linear Read Test
USB Drive F
67
Linear Read Test
USB Drive G
68
Linear Read Test
USB Drive H
69
Linear Read Test
USB Drive J
70
Linear Read Test
USB Drive 1
71
Linear Read Test
USB Drive L
72
Linear Read Test
Test ID
Test Name
Intel(R) HD Graphics 630
73
Shader Rendering DXllTest
74
Multiple Rendering DX9Test
75
Thermal Cycle Test
76
Shader Rendering DXlOTest
77
Wireframe Shader RenderingTest
78
Shader RenderingTest
79
GPU Pipeline Data Test
80
Transformation and Lighting Stress Test
81
Wireframe Stress Test
82
Fixed Transformation and LightingTest
83
Wireframe Line Test
84
Primary Surface Test
85
Video Memory Test
AVI Test
86
AVI Interactive Test
DELL E1916H (Generic PnP Monitor)
87
EDID Checksum Test
88
Monitor Interactive Test
HID Keyboard Device
89 Keyboard Interactive Test
HID-compliant mouse
90
Mouse Interactive Test
Intel(R) Ethernet Connection (2) 1219-LM
91
Network Link Test
92
TCP/IP Internal LoopbackTest
93
Network External LoopbackTest
Figure 3-1 PC Doctor Service Center™ system tests and test identification codes.
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3.8 Location of Control Equipment
The control group accompanied the test group throughout the process (except inside the chamber)
however; the controls were isolated from the test group by placing each in separate primary
containment (i.e., trays for Cat. 2 and 3 materials and static intercept bags for Cat. 4 materials). Control
materials remained outside the COMMANDER chamber during release of the PAAfog or LCHPV to avoid
exposure.
3.9 Representative Samples
Categories 2 and 3 materials are representative of materials present in limited amounts in areas or
buildings that may require fumigation. Category 2 coupons were cut to avoid the factory edge, which
may not have been representative of the bulk material.
Category 4 materials were chosen to be representative not only of computers typical of commercial/
government use; but also as a collection of subsystems representative of a broad range of technological
equipment, from printed circuit boards to optical devices to fan bearings. Each material and equipment
type were tested in triplicate to estimate variability within each. Figures 3-1 through 3-5 show control
samples (not exposed to decontaminant) of the Categories 2, 3, and 4 materials and equipment.
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Figure 3-2. Category 2 metal coupon controls (a) 3003 aluminum, (b) 101 copper, (c) low-carbon steel, (d) 316
stainless steel, (e) 304 stainless steel, (f) 410 stainless steel, (g) 430 stainless steel, and (h) 309 stainless steel.
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Figure 3-3. Category 2 material controls (a) DSL line conditioner, (b) switch (incandescent light), (c) steel
outlet/switch box, (d) silicone caulk (circled in yellow), (e) yellow SJTO 300 VAC service cord, (f) smoke
detector (cover removed), (g) laser-printed paper, (h) ink Jet colored paper, and (i) a color photograph.
21
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Figure 3-3. Category 2 plastic material controls: (a) low-density polyethylene, (b) HDPE plastic film, (c) duct
tape, (d) acrylonitrile butadiene styrene plastic, and (e) PVC plastic.
22
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(a)
(b)
(c)
Figure 3-4. Category 3 equipment controls: (a) mobile phone, (b) printer/fax/scanner/copier machine, (c)
data CD, (d) data DVD, (e) USB flash drive, and (f) SD memory card.
23
-------
Figure 3-5. Category 4 equipment controls: (a) front external tower components {front ports), (b) monitor, (c)
keyboard, (d) mouse, (e) internal tower components, and (f) rear external tower components.
24
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3.10 Material and Equipment Storage and Preservation Methods
Test samples (i.e., materials and equipment) were stored in T/RH controlled, indoor ambient lab
conditions. Both test and control samples were stored at the same conditions before and after the
fogging or LCHPV event.
The Category 4 equipment, specifically the computers and monitors, were placed in anti-static and anti-
corrosion bags (Static Intercept® Technology, http://www.staticintercept.com) during transport. These
bags were developed by Bell Labs and recommended by Alcatel-Lucent. These bags are specifically
designed to protect the bagged equipment from exposure to potentially damaging electrostatic charge
or corrosive gases (Intercept Technology, Inc., 2020). The computers and monitors were removed from
their original packaging, labeled with a designated sample number. The Category 4 equipment along
with Categories 2 and 3 equipment and materials were transferred to an appropriate area (ESD
workstation) in which the computers and monitors could remain energized and operated over the
course of a year to continually assess delayed effects due to the exposure conditions.
The inside of the desktop computers were digitally photographed. To maintain the integrity of the
computer, static electricity was avoided with the use of an ESD Station. An ESD station was set-up in a
separate, onsite laboratory in Highbay Building Room 106. The station consisted of an electrostatic
discharge work mat, an electrostatic monitor, and electrostatic discharge wrist bands. All computers
were inspected and operated (e.g., diagnostic testing, long-term operation of computers for analysis of
residual effects) on the certified ESD workstations according to certified procedures. During operation of
the computers, all computers were energized using surge protection receptacles.
25
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4.0 Results and Discussion
4.1 Exposure Test Matrix and Summary of Test Conditions
A total of three decontaminant exposure tests were performed. TestTl dispersed 750 mL of PAA with a
fogger. The subsequent tests, T2 and T3, utilized a humidifier to disperse 3% HP aqueous and 8% HP
aqueous, respectively. Table 4-1 summarizes the test matrix.
Table 4-1. Test Matrix
Test Number
Dissemination
Equipment
Sporicidal Liquid
Prescribed Volume
1
COTS Fogger
PAA1
750 mL
2
COTS Humidifier
3% hydrogen
peroxide2 (aq)
3000 mL
3
COTS Humidifier
8% hydrogen
peroxide2 (aq)
2000 mL
1 Used as received from the manufacturer: 4.5% PAA, 22% H2O2
2 Prepared from a stock of 35% HP (aq)
Aq: aqueous, COTS: commercial off-the-shelf, PAA: peracetic acid
Fogging approximately 300 mL of PAA in a mock office environment in COMMANDER was shown to be
efficacious on nonporous surfaces such as stainless steel and glass with > 6 log reduction of
Bacillus atrophaeus (a surrogate for B. anthracis), in addition to certain porous materials such as paper
and wood (U.S. EPA, 2017c). (A decontaminant achieving > 6 is considered effective [U.S. EPA, 2018]).
However, the conditions proved insufficient to achieve the required 6 log reduction for other porous
materials, such as ceiling tile, carpet, and concrete. In a subsequent study, more rigorous
decontamination conditions were achieved for subway railcar materials by disseminating 31.25 mL/m3
of PAA solution using a comparable fogger (U.S. EPA, 2016). To replicate the HPV conditions in the
railcar, 750 mL of PAA were disseminated in COMMANDER (24 m3) for this investigation.
Similarly, low concentrations of hydrogen peroxide (LCHP) concentrations and volumes disseminated
were consistent with previous studies that utilized a comparable humidifier for HPV decontamination
and demonstrated efficacy against B. anthracis and surrogate spores on both porous and nonporous
materials. A summary of the test conditions is shown in Table 4-2.
26
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Table 4-2. Summary of Test Conditions During Dissemination
Sporicidal
Test ID
Aqueous
H2O2 %
Liquid
Volume
Disseminated
(mL)
Active
Dissemination
Time (hr)
Dwell
Time (hr)
Mean
HPV
(ppm)
Max HPV
(ppm)
Mean
RH
(%)
Max
RH
(%)
Mean
T (°C)
MaxT
(°C)
1
22.0a
746
0.2
19.7
97.8
150.8
60.6
65.9
27.1
28.4
2
2.9
3100
66.6
8.4
3.46
7.71
93.7b
97.3b
24.3b
25.5b
3
8.6
2200
48.7
10.3
10.2
25.3
91.2
95.2
24.0
25.2
a Per the manufacturer's label; PAA concentration 4.5%
bHOBO data used for temperature (T) and relative humidity (RH), since the SCADA RH and temperature data were unavailable
due to malfunction.
HPV: hydrogen peroxide vapor, hr: hour
27
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4.1.1 PAA Fog Test
The PAA fog test was performed with the fogger (Section 2.4.1) having the mist setting on LOW.
Preliminary flow rate checks with deionized water showed the LOW setting disseminated approximately
59 mL/minute (min). A total of 746 mL of PAA were disseminated during the exposure; 750 mL of PAA
were added to the fogger prior to activation and 4 mL of PAA were retrieved upon re-entry the following
day. Active PAA fog generation continued for approximately 11 minutes prior to shutting off the fogger,
followed by a dwell time of approximately 19 hours prior to starting chamber aeration. Figure 4-1
shows the HPV concentration over the duration of the exposure and during the initial 2 hours of the PAA
fog test.
Date +Time
Figure 4-1. HPV concentration during PAA fog test.
4.1.2 3% LCHP Test
The COTS humidifier used for the preliminary test was reused for the 3% LCHP test with a new, unused
replacement filter installed. With the information from the preliminary test, approximately 1 L was
expected to remain in the fogger upon re-entry. 3% LCHP solution was prepared and analyzed to be
2.93% HP (aq). To achieve the targeted 3-L dissemination volume, 4-L of the prepared solution were
equally divided between the humidifier tanks. The humidifier was transferred to the COMMANDER
chamber and placed on the chamber floor. The humidifier settings were configured for high humidity
and low fan output. A new oscillating fan was installed in the chamber and plugged into the circuit
controlled by the SCADA system. The COMMANDER chamber was sealed and configured for zero air
exchanges. The humidifier and mixing fan were powered on remotely activating the humidifier using the
SCADA system. Figure 4-2 shows the HPV concentration over the duration of the exposure event.
28
-------
9.00
8.00
7.00
6.00
E 5.00
Q.
¦B 4.00
>
£ 3.00
2.00
1.00
0.00
100
Date + Time
Figure 4-2. HPV concentration during 3% LCHP test.
The COMMANDER uninterruptible power supply (UPS) failed approximately 9 hours into the exposure.
The UPS powered the SCADA system which, powered the humidifier, mixing fan and the, personal data
acquisition (pDAQ) system used to power and record readings from the HP Analytical Technology, Inc.
(ATI) 2-wire gas transmitter, Viasala humidity probe, and the thermocouple. Approximately 9 Vz hours
after power was lost, the humidifier, fan, and pDaq were restored by moving the power source to an
unaffected circuit. This "dark" period of lost power is shown in Figure 4-2 during Days 1 and 2. The
reported RH and temperature data were collected from the deployed HOBO logger positioned on the
table with the test materials and equipment. Although we lost HPV data during this time period, from
Figure 4-2, it appears the HPV concentration remained in the range of approximately 4-5 ppm, and so
we can reasonably conclude that the lost power did not affect the equipment and materials' exposure to
the HPV.
4.1.3 8% LCHP Test
A new COTS humidifier (same brand) was used for the 8% LCHP test. The target volume for
dissemination was 2 L, therefore, 3 L were added. The solution was prepared from 35% stock. Analysis
of the HP (aq) concentration of prepared solution returned 8.6%. The prepared solution was transferred
to the humidifier by adding 1.5 L to each of the two tanks. As with the previous HPV test, the humidifier
settings were configured for high humidity and low fan output. A new oscillating fan was installed in
COMMANDER and powered on. The 8% LCHP dissemination began by remotely activating the unit via
the SCADA system. Figure 4-3 shows the HPV concentration inside the COMMANDER chamber during
the exposure test.
29
-------
30
25
20
15
10
5
0
5 U-00 ^.00 "°0 ^00 U-00 ^:o0 U-00 ^00 U'00
Figure 4-3. HPV concentration during 8% LCHP test.
The total duration of the exposure was 59 hours (2.4 days) including 48.7 hours of active dissemination
and 10.3 hours of dwell time. The maximum HPV concentration during dissemination was 25 ppm and
the average over the duration of the exposure was 10 ppm (± 4 ppm SD). The amount of 2.2 L was found
to have been disseminated through gravimetric analysis. The amount of 206 mL was collected from the
unit and the remainder was assumed to be left in the filter.
4.2 Visual Inspections
All Category 2,3, and 4 materials and equipment were inspected and photo-documented before and, on
months 1, 3, 6, and 12 after the exposure events. Additionally, an unexposed, control set of materials
and equipment were inspected and photographed for comparison. This section details the documented
physical changes over the 12-month observation period. Unless noted otherwise,
materials/decontaminant combinations not specifically mentioned below were not visually impacted.
4.2.1 Category 2 Materials
The PAAfog exposure resulted in the most observed changes of the three decontaminant methods
evaluated in the study, in terms of number the materials affected and the severity of the impact.
Category 2 metals that showed visually-observed impacts from the PAA fog included copper, low-carbon
steel, 304-stainless steel, and the aluminum switch box. Refer to Table 4-3 and Figures 4-4 through 4-10.
The exposed surface of the copper material showed a thin green layer typical of patina. Low-carbon
steel materials were severely oxidized resulting in complete coverage of a thick layer of rust. The 304
stainless-steel showed minimal effects with a thin layer of residue on the exposed surfaces. Aluminum
surfaces showed a thin layer of crystalized salt residue. The switchbox had the same residue that
appeared on the aluminum material in addition to the rust on the cut edges. The base of incandescent
light was layered with what appeared to be the same residue found on the aluminum material and
switch box. Additionally, the internal surface of the socket showed a layer of green residue resembling
patina. The visual observations documented on month 12 were the same as those documented on Day 7
30
-------
after exposure. The conditions of these materials were consistent throughout the observation period;
they neither worsened nor improved.
Both the laser and inkjet-printed papers were also affected by the PAA exposure. The first page of each
stack was the most affected as expected. Fully exposed to the test environment, the condition of the
first page deteriorated over time. Over the initial 3 months of inspection, the edges of the page were
progressively more brittle with each inspection. The damage appeared to be consistent between
months 6 and 12. It was difficult to manipulate the page without causing further damage. Traveling
further into the stack of paper reveals less of this damage. Pages 7 and 15 of both laser and inkjet
papers did not share these effects. A notable difference between laser and inkjet copies is the inkjet ink
traveled through the page; this occurred for images throughout the entire stack. Ink bleed was not
observed with the laser copies.
With regard to the LCHPV exposures, low-carbon steel showed no sign of physical changes from the 3%
exposure on Day 7. Trace levels of oxidation were observed during month 1 after the 3% exposure and
Day 7 after the 8% exposure. For both HP exposures, the initially small active areas grew and appear to
stabilize after month 6.
The remaining Category 2 materials exposed to the 3% and 8% LCHPV exposures were visually
unaffected. A description of the visually-observed changes documented in Category 2 materials are
detailed in Table 4-3 and shown in Figures 4-4 through 4-10. Materials not discussed in this Section
showed no indication of change.
31
-------
Table 4-3. Summary of Visually-Observed Changes for Impacted Category 2 Materials
Treatment Material Visually-Observed Changes
Copper
Moderate amount of green patina formed on
surfaces of each replicates
Low-carbon steel
Gross oxidation; rust formed on the surfaces of each
replicate
304-stainless steel
Thin layer of white opaque discoloration
Aluminum
Small amount of white crystalized residue
PAA Fog
Switch box
Rust formed on cut edges, white crystalized residue
on majority of surfaces
Incandescent Light
Green residue on interior surface of socket.
Moderate oxidation (rust) and green residue on plug.
White, chalky residue on metal surfaces of the base.
Printed paper
Significant deterioration around the edges of the 1st
sheet. Pages 7 and 15 do not show any of the
physical impacts of page 1. Bleeding though the page
of inkjet printed pages.
Smoke detector
Corrosion on battery terminals
3% HP
Low-carbon steel
Mild/moderate oxidation - rust formation on the
surfaces of each replicate
8% HP
Low-carbon steel
Mild/moderate oxidation - rust formation on the
surfaces of each replicate
Materials not included in this table were visibly unaffected during the observation period.
32
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Figure 4-4. Copper coupons at month 12 after: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP exposures.
(a) (b) (c) (d)
6 - HPV.1 - 2CU - 03
5-0) J
Figure 4-5. Low carbon steel at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
Figure 4-6. Type 304 stainless steel coupons at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8%
LCHP solutions.
33
-------
Figure 4-7, Aluminum at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
(a) (b) (c) (d)
Figure 4-8. Switch box at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
(a) (b) (c) (d)
Figure 4-9. Light with switch at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
34
-------
(a) (b) (c) (d)
m :
— gjpSisw**
^ l|
b . ,
" S^ESSSSKSr~
/ ftHK 1
l] H ;\
ii\
O j
ITi
O
O
Figure 4-10. Inkjet-printed paper at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP
solutions.
4.2.2 Category 3 Equipment
As with Category 2 materials, the PAA fog exposure produced more visually-observed changes in Category 3
equipment than the two LCHP exposures. The PAA-affected equipment included the SD memory card, USB flash
drive, and the all-in-one printer. Changes observed on the SD card include green residue on the metal pins. The
USB flash drive also showed a small amount of residue on the metal surfaces. As with the switch box, the all-in-
one printer had rust on the cut edges of the metal component of the roller assembly.
The Category 3 materials exposed to the 3% and 8% LCHP exposures were visually unaffected. A description of
the visually-observed changes documented in Category 3 materials are detailed in Table 4-4. Visually-observed
changes are shown in Figures 4-11, 4-12, and 4-13.
Table 4-4. Summary of Visually-Observed Changes for Category 3 Equipment
Treatment
Equipment
Visual Observations
SD Memory Card
Green residue on external surfaces
PAA fog
USB flash drive
Slight corrosion on exposed metal
All-ln-One Printer
Gross color fading on printed label,
diminished coating
Visually-observed changes were not observed in Category 3 equipment exposed to LCHPV from 3% or 8% LCHP
(a) (b) (c) (d)
Figure 4-11. SD Cards at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
35
-------
(a) (b) (c) (d)
Figure 4-12. USBs at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP solutions.
(a) (b) (c) (d)
Figure 4-13. All-ln-One printers at 12-months post-exposure: (a) control, (b) PAA, (c) 3% LCHP, and (d) 8% LCHP
solutions.
4.2.3 Category 4 Equipment
The PAA fog treatment produced similar physical visually-observed changes for Category 4 equipment as were
observed for Category 3 materials. Most notably was the white residue seen on nearly all of the computer
surfaces (internal and external). The build-up of residue on the synthetic surfaces such as cords and the tower
casing suggest it is likely a salt that formed as the PAA droplets dried as opposed to corroded or oxidized metal
surfaces. The residue was also observed in significant quantities on the internal surfaces of the tower chassis. In
addition to the white residue, a relatively small amount of rust had developed on the cut edges of the external
metal surfaces.
There were no significant visually-observed changes observed in the Category 4 computers exposed to either
LCHP treatment.
A description of the visually-observed changes documented in Category 4 materials are detailed in Table 4-4
Computer components for the control set and each exposure are shown in Figures 4-14 through 4-17.
36
-------
Table 4-5. Summary of Visually-Observed Changes in Category 4 Materials
Treatment
Computer Component
Visual Observation
Monitor
White residue
Keyboard
None
PAA Fog
Mouse
None
Tower Exterior
Rust on cut edges of metal material
and white residue
Tower Interior
White residue
Visually-observed changes were not observed in Category 4 equipment exposed to LCHPV from 3% or
8% LCHP
(a) (b) (c)
(d)
Figure 4-14. Control desktop computer at month 12 of the observation period: (a) monitor, (b) keyboard, (c)
computer exterior, and (d) computer interior.
¦Ill''"
Si" *¦¦¦
¦ ¦¦¦"- iW.F?V !¦¦¦
¦¦¦¦¦¦¦¦¦¦¦¦
¦¦¦¦¦¦¦¦¦¦¦¦
¦¦¦¦¦¦¦¦¦¦¦¦
"mm
37
-------
(d)
Figure 4-15. T01 desktop computer 12 months after PAA exposure: (a) monitor, (b) keyboard, (c) computer exterior,
and (d) computer interior.
¦¦¦¦esss:
38
-------
(d)
Figure 4-16. T02 desktop computer 12-months after 3% LCHP exposure: (a) monitor, (b) keyboard, (c) computer
exterior, and (d) computer interior.
39
-------
(a) (b) (c)
Figure 4-17. T03 desktop computer 12-months after 8% LCHP exposure: (a) monitor, (b) keyboard, (c) computer
exterior, and (d) computer interior.
40
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4.3 Functionality Assessments
Functionality assessments were performed on Category 2, 3, and 4 materials and equipment once each
month over the 12-month post-exposure observation period. Assessments were performed by operating
the equipment as intended and specified by the manufacturer. Equipment was assessed on the
successful completion of basic functions in an average operating environment. This section will detail
the results of Category 2, 3, and 4 functionality assessments.
4.3.1 Categories 2 and 3 Equipment
Categories 2 and 3 equipment were powered off and unplugged when not in use. Mobile phones were
fully charged prior to testing. All equipment was stored in an environmentally controlled facility typical
of an indoor office environment. The following is a summary of functionality issues encountered with
equipment exposed to PAA fog. No functionality issues were encountered with the positive control
equipment or with equipment exposured to the LCHPV.
One month following the PAA fog exposure, the mobile phone power button would successfully power
the device on and off, but would not wake the phone from hibernation. To wake the mobile device, an
incoming call had to be placed and the call either ignored or answered. This failure repeated for the
duration of the 12-month observation period.
The incandescent lamp that was exposed to PAA fog failed to switch on the CFL bulb at the 3-month
test. A second attempt was made with a new bulb, but proved unsuccessful. It was later determined
that the power outlet used was likely not energized. There were no failures observed before or after this
instance.
During the 7-day post-exposure assessment, the smoke detector that was exposed to PAA fog would
periodically produce a chirp-like beep typical of a low battery alert. The alert continued after replacing
the battery. The unit ceased to produce the alert at the 4-month post exposure assessment, but
otherwise functioned properly. Table 4-6 summarizes the functionality issues observed in the Category
2 and 3 materials during the 12-month observation period. Since only one replicate of each piece of
equipment was exposed, it is not possible to determine statistical significance.
Table 4-6. Functionality Issues Found for Category 2 and 3 Equipment
Treatment
Equipment
Functional Change
Incandescent Light Switch1
Inability to power light source on and off, tested by installing a CFL
light bulb. This failure only occurred during month 3 post-exposure.
PAA fog
Mobile phone
The power button would not wake the phone or power the phone off.
Smoke detector
Unit would produce an unprompted chirp typical of a low battery alert
and continued after a new battery was installed.
1 Failure is inconclusive. There is a strong possibility that the power outlet was not energized when the failure occurred.
PAA: peracetic acid
4.3.2 Category 4 Materials Functionality Assessment
41
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PC Doctor™ functionality testing was conducted prior to the decontaminant exposure event and
monthly thereafter. The temporal evaluation of the computers provided information about the
progression and extent of damage to the computer subsystems over time.
A number of failed diagnostic tests occurred in the set of control computers, and these issues also
occurred with the test group of computers. Failures observed in the decontaminant-exposed computers
that were observed in the control set are detailed in the following sections.
Except for the few minor issues with the PAA fog exposure as noted in the following sections, there
were no other functionality impacts of Category 4 equipment from exposure to the PAA fog. There were
no additional functionality impacts to Category 4 equipment from exposure to either of the LCHPV
exposures apart from what was observed with the control computers.
As previously mentioned, a test that failed the first trial was tested a second time to correct for possible
human error. A test that failed the second trial was labeled "Fail." If the test failed the first time, but
passes the second time, it was labeled "Pass2." For tabulation, a score of 1,000 is assigned to each
"Fail," and a "Pass2" is assigned a score of 1. A "Pass" results in a score of 0.
4.3.2.1 Control Set Assessments
A set of triplicate, unexposed computers (PC-01, PC-02, and PC-03) provided a baseline for comparison
with the decontaminant-exposed computers. PC Doctor tests for the untreated, control set were
conducted in parallel with the PAA fog treated computers. Although the control set was not exposed to
treatment conditions, a number of system failures were reported in the optical drives over the
observation period. It is important to note that the computers used for this study were configured with
2 separate optical drives: a rewritable drive (+- RW) and a read-only memory (ROM). The rewritable
drive experienced the most test failures with a total of 122 failures for the three control computers.
Observed failures in this drive began on Day 202 of the observation period and, with few exceptions,
consistently failed both test trials for each subsequent assessment. The ROM drive totaled 7 failures, all
from PC-02. The first instance occurred on Day 146 with both test trials failing. Subsequent failures
occurred on Days 202 and 321; the tests on these days failed the initial trial, but passed the second.
Infrequent sub-system failures included the sound card, USB, and network card. The sound card failure
occurred in PC-02 on Day 70; the initial test trial failed and the second passed. The USB Drive for PC-03
failed both test trials on Day 39, but performed without further incident thereafter. Two network card
failures were detected on Day 108 for PC-01. For both tests, the initial test trial failed, but the second
test trial passed.
Table 4-7 provides a summary of the failed test and their corresponding subsystems for the control set
of computers. Tables 4-8, 4-9, and 4-10 provide monthly assessment scores, test failures and the
frequency of the failures over the observation period for the control set.
42
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Table 4-7. Summary of Failed Tests and Corresponding Subsystems for the Category 4
Control Set
Failed Test ID
Test Description
Sub-System
Total Failures
1
Rough Audio Test
Sound Card
1
26
DVD Linear Seek Test
+- RW Drive
11
27
DVD Linear Read Compare Test
+- RW Drive
11
28
DVD Random Seek Test
+- RW Drive
11
29
DVD Funnel Seek Test
+- RW Drive
11
30
DVD Read Performance Test
+- RW Drive
11
42
DVD Linear Seek Test
ROM Drive
3
44
DVD Random Seek Test
ROM Drive
2
45
DVD Funnel Seek Test
ROM Drive
2
60
CD-RW Read Write Test
+- RW Drive
1
61
DVD-R Read Write Test
+- RW Drive
20
62
DVD-RW Read Write Test
+- RW Drive
15
63
DVD+R Read Write Test
+- RW Drive
17
64
DVD+RW Read Write Test
+- RW Drive
14
70
Linear Read Test
USB
1
91
Network Link Test
Network Card
1
93
Network External LoopbackTest
Network Card
1
Table 4-8. PC-Doctor™ Scores and Failed Test IDs for PC-01 (Control)
Monthly Scores
Failed Test ID
Month
Elapsed Time (Days)
Score
Baseline
-22
0
Jul
7
0
Aug
39
0
Sep
70
0
Oct
108
2
91a
93a
Nov
140
1000
63
Dec1
N/A
Jan
202
2000
63
64
Feb
227
3000
61
62
63
Mar
259
8001
26
27
28
29
30
60a
61
62
63
Apr
284
9000
26
27
28
29
30
61
62
63
64
May
321
9000
26
27
28
29
30
61
62
63
64
Jun
355
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial
1Data is not available. The test facility could not be accessed. Blank cells indicate no failed tests.
43
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Table 4-9. PC-Doctor™ Scores and Failed Test IDs for PC-02 (Control)
Monthly Score Summary
Failed Test ID
Month
Elapsed
Time (Days)
Score
Baseline
-22
0
Jul
7
0
Aug
39
0
Sep
70
1
r
Oct
108
0
Nov
146
0
42
44
45
Dec1
N/A
Jan
202
1004
42a
44a
45a
62a
63
Feb
227
3000
62
63
64
Mar
259
3000
62
63
64
Apr
284
9000
26
27
28
29
30
61
62
63
64
May
321
9001
26
27
28
29
30
42a
61
62
63
64
Jun
355
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial
1Data is not available. The test facility could not be accessed. Blank cells indicate no failed tests.
Table 4-10. PC-Doctor™ Scores and Test Failure IDs PC-03 (Control)
Monthly Scores
Failed Test ID
Month
Elapsed
Time (Days)
*Score
Baseline
-4
0
Jul
7
0
Aug
39
1000
70
Sep
70
0
Oct
108
0
Nov
140
1000
64
Dec1
NA
Jan
202
4000
61
62
63
64
Feb
227
4000
61
62
63
64
Mar
259
9000
26
27
28
29
30
61
62
63
64
Apr
284
9000
26
27
28
29
30
61
62
63
64
May
321
9000
26
27
28
29
30
61
61
61
61
Jun
355
9000
26
27
28
29
30
61
61
61
61
1Data is not available. The test facility could not be accessed. Blank cells indicate no failed tests.
44
-------
4.3.2.2 PAA Test Assessments
Computers PC-04, PC-05, and PC-06 were exposed to the PAA fog. The computers successfully
completed diagnostic testing without failures up to observation Days 108, 244, and 202, respectively. As
subsystems began to fail, failed tests and the frequency of failure were consistent with the control set of
computers, with the majority of failures associated with the +-RW drive (119 total tests). Failed
subsystems that also occurred in the control group included the sound card (total of 1 failure). There
were three +-RW test failures that occurred with PAA fog exposure that did not occur in the control set.
They include the Spindle, Tray In, and CD Linear Seek tests. The Spindle and Tray In tests failed the initial
test, but passed the second on Day 244 for PC-04. Additionally, these failures were unique for this set of
computers; they did not occur a second time. The CD Linear Seek test was performed as Tests 21 and 48
for the +-RW and both failed for PC-04. The two failures occurred on days 202 and 271, and only failed
the initial test trial. The ROM drive failures include CD Funnel Seek and CD Linear Seek tests. The CD
Linear Seek test failure occurred at Day 202 for PC-06. The CD Funnel Seek test also occurred at Day 202
for PC-04. Table 4-11 provides a summary of the failed test and their corresponding subsystems for the
computers exposed to PAA fog. Tables 4-12, 4-13, and 4-14 provide monthly assessment scores, test
failures and the frequency of the failures over the observation period.
45
-------
Table 4-11. Summary of Failed Tests and Corresponding Subsystems for the PAA Fog
Test Category 4 Set
Test ID1
Test Description
Subsystem
Total Failures
1
Rough Audio Test
Sound Card
1
18*
Spindle Test
+- RW Drive
1
20*
Tray In Test
+- RW Drive
1
21*
CD Linear Seek Test
+- RW Drive
1
26
DVD Linear Seek Test
+- RW Drive
12
27
DVD Linear Read Compare Test
+- RW Drive
11
28
DVD Random Seek Test
+- RW Drive
11
29
DVD Funnel Seek Test
+- RW Drive
11
30
DVD Read Performance Test
+- RW Drive
11
40*
CD Funnel Seek Test
ROM Drive
1
48*
CD Linear Seek Test
+- RW Drive
1
54*
CD Linear Seek Test
ROM Drive
1
61
DVD-R Read Write Test
+- RW Drive
15
62
DVD-RW Read Write Test
+- RW Drive
17
63
DVD+R Read Write Test
+- RW Drive
15
64
DVD+RW Read Write Test
+- RW Drive
12
1Test failures that did not also occur in the control set are highlighted and have an asterisk.
Table 4-12. PC-Doctor™ Scores and Failed Tests for PC-04 (PAA)
IV
Month
lonthly Scores
Elapsed
Time (Days)
Score
Failed Test ID2
Baseline
-22
0
Jul
7
0
Aug
39
0
Sep
70
0
Oct
108
2
r
61a
Nov
140
2000
62
63
Dec1
N/A
Jan
202
1005
48a*
54a**
61a
62a
63a
64
Feb
227
4000
61
62
63
Mar
244
8002
18a*
20a*
26
27
28
29
30
61
62
63
Apr
271
9001
21a*
26
27
28
29
30
61
62
63
64
May
316
9000
26
27
28
29
30
61
62
63
64
Jun
355
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial
1 Data is not available. The test facility could not be accessed.
2Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
46
-------
Table 4-13. PC-Doctor™ Scores and System Failures for PC-05 (PAA)
M
Month
Dnthly Scores
Elapsed
Time (Days)
Score
Failed Test ID
Baseline
-22
0
Jul
7
0
Aug
39
0
Sep
70
0
Oct
108
0
Nov
140
0
Dec1
N/A
Jan
202
0
Feb
227
0
Mar
244
1000
62
Apr
271
1000
62
May
316
6003
26
27
28a
29a
30a
61
62
63
64
Jun
355
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial
1 Data is not available. The test facility could not be accessed. Blank cells indicate no failed tests.
Table 4-14. Monthly PC-Doctor™ Scores and System Failures for PC-06 (PAA)
Mont
Month
lly Scor(
Day
;s
Score
Failed Test ID2
Baseline
-22
0
Jul
7
0
Aug
39
0
Sep
70
0
Oct
108
0
Nov
140
0
Dec1
N/A
Jan
202
4002
26
40
a*
61a
62
63
64
Feb
227
9000
26
27
28
29
30
61
62
63
64
Mar
244
9000
26
27
28
29
30
61
62
63
64
Apr
271
9000
26
27
28
29
30
61
62
63
64
May
316
9000
26
27
28
29
30
61
62
63
64
Jun
355
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial.
1 Data is not available. The test facility could not be accessed.
2 Test failures that did not also occur in the control set are highlighted. And have an asterisk. Blank cells indicate
no failed tests.
47
-------
4.3.2.3 3% LCHP Test Assessments
Computers PC-07, PC-08, and PC-09 were exposed to the HPV from 3% LCHP. The computers were
assessed without subsystem failures until Days 82, 37, and 177, respectively. When failures occurred,
the majority were associated with the +-RW drive. Upon completion of the observation period, the +-
RW drive test failures totaled 107, of which only 5 were not represented in the control set. These
included the OPU, Spindle, Tray In, and CD Linear Seek tests. An OPU test failure was recorded for PC-07
and PC-08, both on Day 246. PC-07 failed the initial test trial and passed the second while, PC-08 failed
both test trials. The Spindle and Tray In failures were recorded for PC-07 on assessment Day 246. The
spindle test failed the first test trial and passed the second while the Tray In test failed both test trials.
The CD Linear Seek test failed for PC-08 on Day 37; the initial test trial failed and the second passed.
Additional test failures include the Rough Audio and DVD Linear Seek tests, which are associated with
the sound card and ROM drive, respectively. Both tests failures also occurred in the control set. Table 4-
15 provides a summary of the failed test and their corresponding subsystems for the control set of
computers. Tables 4-16, 4-17, and 4-18 provide monthly assessment scores, test failures and the
frequency of the failures over the observation period.
48
-------
Table 4-15. Summary of Failed Tests and Corresponding Subsystems for the Category 4
3% LCHP Test Set
Test ID1
Test Description
Subsystem
Total Failures
1
Rough Audio Test
Sound Card
2
17
OPU Test
+- RW Drive
2
18
Spindle Test
+- RW Drive
1
20
Tray In Test
+- RW Drive
1
21
CD Linear Seek Test
+- RW Drive
1
26
DVD Linear Seek Test
+- RW Drive
8
27
DVD Linear Read Compare Test
+- RW Drive
8
28
DVD Random Seek Test
+- RW Drive
7
29
DVD Funnel Seek Test
+- RW Drive
7
30
DVD Read Performance Test
+- RW Drive
7
42
DVD Linear Seek Test
ROM Drive
1
60
CD-RW Read Write Test
+- RW Drive
4
61
DVD-R Read Write Test
+- RW Drive
14
62
DVD-RW Read Write Test
+- RW Drive
10
63
DVD+R Read Write Test
+- RW Drive
17
64
DVD+RW Read Write Test
+- RW Drive
20
67*
Linear Read Test
USB Device
7
1 Test failures that did not also occur in the control set are highlighted and have an asterisk.
Table 4-16. Monthly PC-Doctor™ Scores and System Failures for PC-07 (3% LCHP)
Mo
Month
nthly Score Sumr
Elapsed Time
(Day)
nary
Score
Failed Test ID1
Baseline
-11
0
Mar
9
0
Apr
37
0
May
82
1000
67
Jun
114
3000
63
64
67*
Jul
136
3000
63
64
67*
Aug
177
5000
61
62
63
64
67*
Sep
213
5000
61
62
63
64
67*
Oct
246
11002
17 a.
18a*
20*
26
27
28
29
30
60
61
62
63
64
Nov
276
12000
26
27
28
29
30
59
60
61
62
63
64
67*
Dec
298
10000
26
27
28
29
30
61
62
63
64
67*
Jan
325
11000
26
27
28
29
30
60
61
62
63
64
67*
Feb
360
11000
26
27
28
29
30
60
61
62
63
64
67*
a Test failed the first trial and passed the second trial
1 Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
49
-------
Table 4-17. Monthly PC-Doctor™ Scores and System Failures for PC-08 (3% LCHP)
Mont
Month
lly Score Summ
Elapsed Time
(Days)
ary
Score
Failed Test ID1
Baseline
-11
0
Mar
9
0
Apr
37
1
21a*
May
82
0
Jun
114
0
Jul
136
1
64a
Aug
177
3000
61
63
64
Sep
213
3000
61
63
64
Oct
246
3000
17*
61
63
Nov
642
2003
la
26a
27a
63
64
Dec
664
4000
61
62
63
64
Jan
325
9000
26
27
28
29
30
61
62
63
64
Feb
360
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second trial
1Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
Table 4-18. Monthly PC-Doctor™ Scores and System Failures for PC-09 (3% LCHP)
Monl
Month
thly Score Summa
Elapsed Time
(Days)
ry
Score
Failed Test ID1
Baseline
-11
0
Mar
9
0
Apr
37
0
May
82
0
Jun
114
0
Jul
136
0
Aug
177
1000
64
Sep
213
1000
64
Oct
246
0
Nov
276
0
Dec
664
1
64a
Jan
325
0
Feb
360
1004
la
42
61a
63a
64a
a Test failed the first trial, but passed the second. Blank cells indicate no failed tests.
50
-------
4.3.2.4 8% LCHP Test Assessments
Computers PC-10, PC-11, and PC-12 were decontaminated with HPV from 8% LCHP. PC-10 experienced
a failed CD Linear Seek test (+-RW drive) on Day 9 however, the next failure did not occur until the
assessment performed on Day 122. Assessments for PC-11 and PC-12 were completed without failures
until Days 100 and 163, respectfully. A total of 90 subsystem failures occurred in this set of computers
including 82 +-RW, 1 sound card, and 2 USB subsystem failures. Test failures that did not occur with the
control PCs were minor, but included the Sound Interactive (sound card), CD Linear Seek (+-RW drive),
and the Linear Read (USB) tests.
A Linear Read Test failure occurred in a USB drive, which was likely caused by an improperly seated USB
device. The initial test trial failed, however, physical adjustment to the USB device resulted in a
successful second test trial.
Table 4-19 provides a summary of the failed tests and their corresponding subsystems for the
computers exposed to the HPV generated from the 8% HP. Tables 4-20, 4-21, and 4-22 provide monthly
assessment scores, test failures and the frequency of the failures over the observation period.
51
-------
Table 4-19. Summary of Failed Tests and Corresponding Subsystems for the Category 4
8% LCHP Test Set
Test ID1
Test Description
Subsystem
Total Failures
2*
Sound Interactive Test
Sound Card
1
21*
CD Linear Seek Test
+- RW Drive
1
26
DVD Linear Seek Test
+- RW Drive
7
27
DVD Linear Read Compare Test
+- RW Drive
7
28
DVD Random Seek Test
+- RW Drive
7
29
DVD Funnel Seek Test
+- RW Drive
7
30
DVD Read Performance Test
+- RW Drive
7
59*
CD-R Read Write Test
+- RW Drive
1
61
DVD-R Read Write Test
+- RW Drive
8
62
DVD-RW Read Write Test
+- RW Drive
10
63
DVD+R Read Write Test
+- RW Drive
15
64
DVD+RW Read Write Test
+- RW Drive
14
65
Linear Read Test
USB
1
67*
Linear Read Test
USB
5
1Test failures that did not also occur in the control set are highlighted and have an asterisk.
Table 4-20. Monthly PC-Doctor™ Scores and System Failures for PC-10 (8% LCHP)
Mon
:hly Score
s
Month
Day
Score
Failed Test ID1
Baseline
-25
0
Mar
9
1
21*a
Apr
36
0
May
73
0
Jun
100
0
Jul
122
0
Aug
163
0
61
63
Sep
199
2000
61
63
Oct
232
2001
62a
63
64
Nov
262
1
63a
Dec
284
4004
26a
27a
28a
29a
30
61
62
63
Jan
311
9000
26
27
28
29
30
61
62
63
64
Feb
346
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second.
1Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
52
-------
Table 4-21. Monthly PC-Doctor™ Scores and System Failures for PC-11 (8% LCHP)
Month
Monthly Scores
Elapsed Time (Day)
Score
Failed Test ID1
Baseline
-11
0
Mar
9
0
Apr
36
0
May
73
0
Jun
100
2000
63
64
Jul
122
2000
63
64
Aug
163
0
Sep
199
0
Oct
232
1002
2*a
64a
67*
Nov
262
1000
67
Dec
284
1000
67
Jan
311
1001
64a
67
Feb
346
9000
62a
63
67*
a Test failed the first trial and passed the second.
1 Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
53
-------
Table 4-22. Monthly PC-Doctor™ Scores and System Failures for PC-12 (8% LCHP)
r
Month
k/lonthly Scores
Elapsed Time
(Days)
Score
Failed Test ID1
Baseline
-11
1
65a
Mar
9
0
Apr
36
0
May
73
0
Jun
100
0
Jul
122
0
Aug
163
1000
64
Sep
199
1000
64
Oct
232
1002
62a
63a
64
Nov
262
2006
26a
27a
28a
29a
30a
62a
63
64
Dec
284
9001
26
27
28
29
30
59*a
61
62
63
64
Jan
311
9000
26
27
28
29
30
61
62
63
64
Feb
346
9000
26
27
28
29
30
61
62
63
64
a Test failed the first trial and passed the second
1Test failures that did not also occur in the control set are highlighted and have an asterisk. Blank cells indicate no
failed tests.
54
-------
4.4 Decontaminant Effectiveness
Table 4-23 shows the number of Bis inactivated by each test decontaminant for each of the test
locations.
Table 4-23. Inactivated Biological Indicator (Bis) for Each Location
Test Solution
Bl Location
Total Bis
No. Inactivated (No Growth)
PAA
PC-04
5
5
PC-05
5
5
PC-06
5
5
Table
5
5
Airlock1
5
0
3% LCHP
PC-07
5
5
PC-08
5
5
PC-09
5
5
Table
5
5
Airlockb
5
0
8% LCHP
PC-10
5
5
PC-11
5
5
PC-12
5
5
Table
5
5
Airlockb
5
0
a Located inside of COMMANDER; fully exposed
b Located outside of COMMANDER; unexposed to decontaminant
No.: Number
Bis not exposed to the PAA fog or LCHPV conditions (i.e. positive controls placed in the air lock) were
positive for growth for each decontamination event. All Bis were inactivated for each of the 3 exposures.
5.0 Quality Control/ Quality Assurance
Quality assurance (QA)/quality control (QC) procedures were performed in accordance with the quality
requirements detailed in an approved quality assurance project plan.
5.1 Sampling, Monitoring, and Equipment Calibration
Approved operating procedures were used for the maintenance and calibration of all laboratory
equipment. All equipment was verified as being certified calibrated or having the calibration validated
by EPA's metrology laboratory at the time of use. Standard laboratory equipment such as balances, pH
meters, biological safety cabinets, and incubators were routinely monitored for proper performance.
Calibration of instruments was done at the frequency shown in Tables 5-1 and 5-2. Any deficiencies
were noted. Any deficient instrument was adjusted to meet calibration tolerances and recalibrated
within 24 hours. If tolerances were not met after recalibration, additional corrective actions were taken,
including recalibration or/and replacement of the equipment.
55
-------
Table 5-1. Sampling and Monitoring Equipment Calibration Frequency
Equipment
Calibration/Certification
Expected
Tolerance
RH and temperature
sensor
Compare RH to the head space of three calibration salt solutions
in an enclosed space within 1 week of use; thermistor (for
temperature) part of RH sensor and calibrated by manufacturer
±5%
ATI HPV transmitter
Compare HPV reading to the head space of a calibration solution
of known concentration within 1 a week of use
±5%
Stopwatch
Compare against National Institute of Standards and Technology
(NIST) Official U.S. time at
http://nist.time.gOv/timezone.cgi7Eastern/d/-5/iava once everv
± 1 min/30 days
30 days
Table 5-2. Analysis Equipment Calibration Frequency
Equipment | Calibration
| Frequency
Calibration Method
Responsible Party
Acceptance Criteria
Pipettes | Annually
Gravimetric
Carter Calibrations,
Manassas, VA
± 1% target value
Scale
Before each use
Compared to Class S
weights
Laboratory staff
± 0.01% target
5.2 Acceptance Criteria for Critical Measurements
QA/QC checks associated with this project were established in a quality assurance project plan. A
summary of these checks is provided in Table 5-3.
Table 5-3. QA/QC Acceptance Criteria for Critical Measurements
Matrix
Critical
Measurement
QA/QC Check
Frequency
Accuracy
Precision
Test Chamber
COMMANDER
2-point
Once per test
±5%
5% of the target
air
chamber HPV
concentration
calibration
concentration
Test Chamber
COMMANDER
Three-point
Once per test
± 3% RH
± 15% RH
air
chamber RH
calibration
(Vaisala, HMK15
humidity
calibrator)
(Vaisala
calibration salt
with certificate)
Test Chamber
COMMANDER
Five-point
Annually
± 0.5 °C
± 5.0 °C
air
chamber
temperature
calibration
5.3 Data Quality
The accuracy of a measurement is expressed in terms of percent bias and precision in relative standard
deviation (RSD). Span values collected during calibrations were used to measure the precision and
accuracy of the ATI HP gas transmitter. For this effort, multiple cell HPV concentrations were used for
the span and, therefore, a precision value is not available. Calibration requires adjustment of both zero
and span. The zero point was set when the sensor is known to be in an environment free of the target
56
-------
gas. The span was set by exposing the transmitter to the head space of a known concentration and
temperature of hydrogen peroxide solution. Table 5-4 details the precision and accuracy of the ATI gas
sensor.
Table 5-4. Precision (RSD) and Accuracy (% Bias) Assessments of the ATI HP Gas
Sensor
Calibration
Cell (wt/wt%
HP)
Calibration
Cell
Headspace
(ppm HPV)
Calibration
Cell
Temperature
(°C)
Adjusted ATI Reading (ppm
HPV)
Precision
(RSD)
Accuracy
(% error)
T01
T02
T03
Baseline1
0
-
0
0
0
NA
NA
8%
32.2
22.4
-
31
-
NA
3.7
16.6%
46.1
15
-
-
49
NA
6.3
48.6%
545a
23.8
545
-
-
NA
0
1 HPV reading in ambient air at ambient temperature.
a 0-1000 ppm range ATI
RSD: relative standard deviation
Precision and accuracy assessments for the Vaisala transmitter's RH sensor were performed prior to
each exposure test. The sensor was calibrated using a HMK15 humidity calibrator (Vaisala, Helsinki,
Finland) placed in selected cells of saturated salt solutions of known relative humidity (Greenspan, 1976)
for a duration of at least 2 hours. The first hour was provided for the response to stabilize; data
collected during the final hour was used for data quality indicator assessments. LabView data acquisition
software was used to digitally record the data. Precision and accuracy assessments for the Vaisala
transmitter's sensor are reported in Table 5-5.
Table 5-5. Precision (RSD) and Accuracy (% Bias) Assessments of the Vaisala
Transmitter's RH Sensor
Salt
Calibration
Cell RH1 (%, ±
SD)
Mean Sensor Measurement (%, ±SD)
Precision
(RSD)
Accuracy
(% bias)
T01
T02
T03
MgCI
33.07 ± 0.48
33.4 ±0.03
32.9 ±0.05
33.2 ±0.01
0.008
-0.29
Mg(N03)2
54.38 ±0.23
54.1 ±0.01
-
-
NA
0.51
NaCI
75.47 ±0.14
75.4 ±0.05
75.3 ±0.01
74.9 ±0.14
0.004
0.36
K2SO4
97.59 ±0.53
-
97.6 ±0.003
97.8 ±0.35
0.001
-0.11
1 Equilibrium relative humidity of saturated salt cell at 20°C
RSD: relative standard deviation
6.0Summary and Conclusions
6.1 PAA Fog Exposure
In terms of decontamination efficacy, fogging 750 ml of PAA into COMMANDER inactivated all the Bis.
Fogging of PAA solutions has potential as a relatively easy-to-use decontamination technology in the
event of contamination with Bacillus anthracis or other spore-forming infectious disease agents (Wood
et al., 2013), however, there are a few notable material incompatibilities to be aware of. Visually-
57
-------
observed changes (e.g., discoloration, residue) were observed on the following metal coupons: copper,
low-carbon steel, 304 stainless steel, and aluminum. Some corrosion and/or residue was also observed
on certain locations of the electrical switch box, incandescent light, and the smoke detector battery
terminals. For the computers, the external, non-metal surfaces had a moderate amount of white, salt
residue. Internal and external metal surfaces showed small amounts of rusting and a significant amount of
white residue.
Changes in equipment functionality or impacts include:
• Printed paper - The PAA fog solution appeared to soak through the top few pages. For those
pages, the integrity of the standard printer paper was shown to deteriorate overtime; becoming
too brittle to handle or use within 6 months of exposure.
• Mobile smart phone - One month following exposure, the power button failed to power the
device on and off or wake the phone from hibernation
• Smoke detector - The unit would give a false "low battery" alert.
• Category 4 computers - A total of six subsystem test failures, not observed in the control set,
were observed in the Category 4 computers; 4 were related to the +-RW drive and 2 to the ROM
drive.
6.2 LCHPV generated with 3% HP
Disseminating 3-L of 3% HP using a COTS humidifier resulted in the inactivation of all 20 Bis. The
dissemination phase required approximately 2.75 days and the dwell phase, 8 hours. During
dissemination, the HP levels reached 7.7 ppm and averaged 3.5 ppm.
The LCHPV exposure resulted in minimal compatibility issues with the Category 2, 3, and 4 materials and
equipment. Visually-observed changes in material and equipment were limited to low-carbon steel,
which showed some minor oxidation as rust on exposed surfaces. While the amount of visible rust was
initially minute, affected areas continued to progress over the surface of the material until
approximately 6-months post-exposure.
The exposure did not affect the functionality of Category 2 or 3 equipment. Four unique subsystem test
failures, not observed in the control set, were observed in the Category 4 computers; all were related to
the +-RW drive.
6.3 LCHPV generated with 8% HP
Disseminating 2-L of 8% HP using a COTS humidifier successfully inactivated all Bis. The dissemination
phase lasted approximately 2 days and the dwell phase, 10 hours. During dissemination, the HP levels
reached 25 ppm and averaged 10 ppm.
The LCHPV exposure using the 8% HP had minimal compatibility issues with the Category 2, 3, and 4
materials and equipment. As with the 3% LCHP exposure, visually-observed changes in material and
58
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equipment were observed on low-carbon steel, which, as before, showed rust on exposed surfaces. The
amount of visible rust also increased over time until approximately 6-months post-exposure.
The exposure did not affect the functionality of Category 2 or 3 equipment. Three unique subsystem
test failures, not observed with the control computers, were observed in the Category 4 computers and
included minor issues with the sound card, +-RW drive, and USB.
6.4 Summary of impacts on personal computers
The impacts on personal computers after exposure to the decontaminants are summarized in Table 6-1,
in terms of the number of second-trial failures that occurred. As previously mentioned, a diagnostic test
on a system that failed the first trial was tested a second time to correct for possible human error. The
number of tests that failed the second trial are summarized below for the positive control computers
and those computers exposed to a decontaminant, and are a more realistic assessment of material
compatibility. Table 6-1 presents the number of occurrences of second-trial failures over the year, in
which the total number of tests conducted was 33 (3 replicate computers for each test condition times
11 assessments over the year). As can been seen in the table, for the PAA fog exposure, there were only
two tests which had more second trial failures compared to the controls; for the 3% LCHP, there were
only three tests which had more second trial failures compared to the controls; and for the 8% LCHP,
there was only one test which had more second trial failures compared to the controls.
Table 6-1. Number of Second-Trial Failures on Personal Computers
Test ID
Test Name
2nd Trial Failures*
Control
PAA
3% LCHP
8% LCHP
17
OPU
1
26
DVD linear seek
11
12
7
5
27
DVD linear read compare
11
11
7
5
28
DVD random seek
11
10
7
5
29
DVD funnel seek
11
10
7
5
30
DVD read performance
11
10
7
6
42
DVD linear seek
1
1
44
DVD random seek
1
45
DVD funnel
1
60
CD-RW read write
4
61
DVD-R read write
20
12
13
8
62
DVD-RW read write
14
16
10
6
63
DVD+R read write
17
14
16
13
64
DVD+RW read write
14
12
17
12
67
USB drive F linear read
5
70
USB drive J linear read
1
*out of a total of 33 tests
59
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7.0 References
Adrion, Alden C., Rudolf H. Scheffrahn, Shannon Serre, and Sang Don Lee. "Impact of sporicidal
fumigation with methyl bromide or methyl iodide on electronic equipment." Journal of
environmental management 231 (2019): 1021-1027.
Greenspan L. (1977). Humidity Fixed Points of Binary Saturated Aqueous Solution. J Res NBS A Phys Ch,
81A (1): 89-95
Intercept Technology, Inc. (2020).
https://www.staticintercept.com/us/index.php?option=com content&view=featured<emid=101
(access March 25, 2020).
Mickelsen R. Leroy, Wood J., Calfee M. Worth, et al. (2019). Low-Concentration Hydrogen Peroxide
Decontamination Procedure for Bacillus Spore Contamination. Remediation Journal 30: 47-56. First
published December 3, 2019. https://onlinelibrarv.wilev.com/doi/full/10.1002/rem.21629
Richter W.R., Wood J.P., Wendling M.Q.S., Rogers J.V. (2018). Inactivation of Bacillus anthracis Spores to
Decontaminate Subway Railcar and Related Materials Via the Fogging of Peracetic Acid and
Hydrogen Peroxide Sporicidal Liquids. J Environ Mgmt. 206: 800-806.
https://doi.Org/10.1016/j.jenvman.2017.ll.027
U.S. Environmental Protection Agency (U.S. EPA). (2010). Compatibility of Material and Electronic
Equipment with Hydrogen Peroxide and Chlorine Dioxide Fumigation. EPA/600/R-10/169. U.S.
Environmental Protection Agency, Washington, DC.
U.S. EPA. (2012). Compatibility of Material and Electronic Equipment with Methyl Bromide and Chlorine
Dioxide Fumigation. EPA/600/R/12/664. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2014). Compatibility of Material and Electronic Equipment with Ethylene Oxide Fumigation.
EPA/600/R-14/399. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2016). Decontamination of Subway Railcar and Related Materials Contaminated with Bacillus
anthracis Spores via the Fogging of Peracetic Acid and Aqueous Hydrogen Peroxide. EPA/600/R-
16/321. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2017a). Material Compatibility for Historic Items Decontaminated with Gamma Irradiation.
EPA/600/R-16/264. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2017b). Low-Concentration Hydrogen Peroxide (LCHP) Vapor for Bioremediation. EPA/542/R-
19/001. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2017c). Fogging of Chlorine-Based Sporicidal Liquids for the Inactivation of Bacillus anthracis
Surrogate Spores. EPA/600/R-17/134. U.S. Environmental Protection Agency, Washington, DC.
U.S. EPA. (2018). Product Performance Test Guidelines OCSPP 810.2100: Sterilants, Sporicides, and
Decontaminants Guidance for Efficacy Testing. EPA 712-C-17-003. U.S. Environmental Protection
Agency, Washington, DC.
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Wood J.P., Calfee M.W., Clayton M., Griffin-Gatchalian. N., Touati A., Egler K. (2013). Evaluation of
Peracetic Acid Fog for the Inactivation of Bacillus anthracis Spore Surrogates in a Large
Decontamination Chamber. J Hazard Mater 250-251:61-67.
Wood J.P., Calfee M.W., Clayton M., Griffin-Gatchalian N., Touati A., Ryan S., Mickelsen L., Smith L.,
Rastogi V. (2016). A simple decontamination approach using hydrogen peroxide vapour for Bacillus
anthracis spore inactivation. J Appl Microbiol. 121: 1603-1615. doi:10.1111/jam.13284
Wood J.P., Adrion A.C. (2019). Review of Decontamination Techniques for the Inactivation of Bacillus
anthracis and other Spore-Forming Bacteria Associated with Building or Outdoor Materials. Environ
Sci Technol. 53 (8): 4045-4062, 10.1021/acs.est.8b05274.
61
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Appendix A
COMM/W > < ' ' V " Ah \o1 v MENTATION
62
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CHILLED WATER
SUPPLY
50 *F
CHILLED WATER
RETURN
MODULATED TO
MAINTAIN NEGATIVE DP
BETWEEN CHAMBER
AND ENCLOSURE
SYMBOL
AAH
AAL
TAH
TE
DESCRIPTION
ANALYSIS ALARM HIGH
ANALYSIS ALARM LOW
ANALYSIS INDICATOR
ANALYSIS TRANSMITTER
FAIL CLOSED
FLOW CONTROL VALVE
FLOW ELEMENT
FLOW INDICATOR
FLOW INDICATING CONTROLLER
FIXED RESTRICTION ORIFICE
FLOW TOTALIZING INDICATOR
FLOW SWITCH
FLOW TRANSMITTER
FLOW VALVE
HAND CONTROL VALVE
POWER CONTROLLER
HIGH LEVEL ALARM
LOW LEVEL ALARM
LEVEL CONTROLLER
LEVEL CONTROL VALVE
MOTOR
LOW PRESSURE ALARM
PRESSURE DIFFERENTIAL INDICATOR
PRESSURE DIFFERENTIAL TRANSMITTER
PRESSURE INDICATOR
PRESSURE INDICATING CONTROLLER
PRESSURE SAFETY ELEMENT
PRESSURE SAFETY
PRESSURE TRANSMITTER
SPEED CONTROLLER
SETPOINT
SOLENOID VALVE
HIGH TEMPERATURE ALARM
TEMPERATURE ELEMENT
TEMPERATURE INDICATING CONTROLLER
TEMPERATURE TRANSMITTER
SPEED MODULATED TO
MAINTAIN NEGATIVE DP
BETWEEN AIR LOCK
AND ENCLOSURE
SYMBOL
DESCRIPTION
\oooJ
FIELD MOUNTED INSTRUMENT
/xx\
PROGRAMMABLE LOGIC CONTROL
\000/
ACCESSIBLE TO OPERATOR
/x*\
PROGRAMMABLE LOGIC CONTROL
INACCESSIBLE TO OPERATOR
(A
PROl*-
SHEET TITLE
UNITED STATES ENVIRONMENTAL
PROTECTION AGENCY
NHSRC CHAMBER
PIPING 8c INSTRUMENTATION
PROJECT NUMBER
RN990234.0001
DEPARTMENT MANAGER
d. proffttt
DRAWING NUMBER
M-1.1
Figure A-l. COMMANDER Piping and Instrumentation.
63
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Appendix B
COMMERCIAL * > ^ > u >; > V " x • x 1NARY TEST
64
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The LCHPV tests were performed with the commercial off-the-shelf (COTS) humidifier described in
Section 2.3.2. Prior to testing with prepared LCHP solution, a preliminary test was performed with
deionized water to characterize chamber conditions and the performance of the humidifier during
testing. Approximately exactly 5 L of deionized water were added to the humidifier; 2500 mL per tank.
The humidifier fan was set to level 1 and the humidistat was set to level 4. The humidifier was placed on
a top Mettler PM30 top loading balance (Mettler Toledo; Columbus, OH) in an empty COMMANDER
chamber with a 12-inch oscillating fan operating set on the highest of 3 speed settings. The
COMMANDER chamber was sealed and configured for zero air exchanges. The humidifier was activated
using the SCADA system and recovered on the sixth day. During the preliminary test, the COMMANDER
chamber was entered periodically to retrieve the mass of the humidifier. Table B-l details the
dissemination rate of the humidifier over the 6-day period of operation.
Table B-1. Total and Average Water Disseminated by COTS Humidifier Over 6 Day Period
Time (Days)
Total Volume
Disseminated (L)
Dissemination Rate
(L/day)
0
0
0
1.0
1.095
1.095
2.0
1.690
0.845
5.7
3.635
0.638
The humidifier lost a total of 1.095, 1.690, and 3.635 liters on Days 1,2, and 6, respectively. The
dissemination rate decreased over time. The initial rate was 1.095 L/day as of 1 day then, dropped to an
average of 0.845 L/day on Day 2 and finally, was an average of 0.638 L/day by Day 6. Approximately 3.6
L of deionized water were disseminated, and 1.4 L remained in the humidifier. Further analysis indicated
approximately 0.6 L of the volume remaining in the humidifier were absorbed in the wicking filter.
Upon re-entry on Day 6, significant amounts of condensation were observed on several chamber
surfaces including the floor, ceiling, and walls. Figure B-l shows a few areas with a significant collection
of condensation after Day 6.
65
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Figure B-l. Condensation after Day 6 of preliminary test (a) next to the humidifier, (b) on the COMMANDER
floor and, (c) on the COMMANDER walls.
66
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vvEPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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