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Office of Research and Development
National Homeland Security Research Center, Decontamination and Consequence Management Division
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EPA/600/R-14/476
March 2015
Decontamination Line Protocol Evaluation for Biological
Contamination Incidents
Assessment and Evaluation Report
National Homeland Security Research Center
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, through its Office of Research and Development, funded and
managed the research described here under contract EP-C-09-027, Work Assignments 4-77 and 5-77,
with ARCADIS U.S., Inc. It has been subjected to the Agency's review and has been approved for
publication. Note that approval does not signify that the contents necessarily reflect the views of the
Agency. Mention of trade names, products, or services does not convey official EPA approval,
endorsement, or recommendation.
Questions concerning this document or its application should be addressed to the principal investigator:
Marshall S. Gray, Jr., MS, CIH
CAPT USPHS
U.S. Environmental Protection Agency
109 T.W. Alexander Drive (Mail Drop: E343-06)
Research Triangle Park, North Carolina 27711
Phone:919-541-0496
Fax:919-541-0602
E-mail: gray.marshall@epa.gov
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Acknowledgments
This effort was directed by the principal investigator, CAPT Marshall Gray, U. S. Public Health Service
(USPHS), of the U.S. Environmental Protection Agency (EPA) Office of Research and Development's
(ORD) National Homeland Research Center (NHSRC), with support from EPA's Office of Emergency
Management (OEM), CBRN Consequence Management Advisory Division (CMAD), and OEM's Bioagent
Workgroup within the Emergency Response Technical Group (ERTG).
Additionally, the contributions of the research project team are acknowledged: Shannon Serre, CMAD; R.
Leroy Mickelsen, CMAD; Worth Calfee, NHSRC; Jayson Griffin, CMAD; and CDR Dino Mattorano,
USPHS.
The research project team gratefully acknowledges quality assurance oversight and review by Ramona
Sherman and Eletha Brady-Roberts, NHSRC, as well as editorial review from Joan Bursey, NHSRC
Senior Environmental Employee Program. The report peer review was provided by Russell Wiener,
NHSRC; Elise Jakabhazy, CMAD; and Natalie Koch, CMAD.
This effort was completed under EPA contract EP-C-09-027 with ARCADIS U.S., Inc. The support and
efforts provided by ARCADIS U.S., Inc. are gratefully acknowledged, as well as assistance from EPA
contract EP-W-12-026 with Dynamac Corporation.
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Table of Contents
Disclaimer ii
Acknowledgments iii
List of Figures vi
List of Tables vii
List of Appendices vii
List of Acronyms and Abbreviations viii
Executive Summary ix
1 Introduction 1
1.1 Process 1
1.2 Project Objectives 2
2 Materials and Methods 3
2.1 Equipment and Supplies 3
2.2 Methods 6
2.2.1 Test Subjects 6
2.2.2 Institutional Review Board 7
2.2.3 Setup 7
2.2.4 "Contaminated Samples" 9
2.2.5 Support Team 9
2.2.6 Test Scripts 9
2.2.7 Test Facility Evaluation after Scripts 1 and 2 11
2.2.8 Decon Line Evaluation Procedures 12
2.2.8.1 Support Zone - Pre-contamination Activities 12
2.2.8.2 Exclusion Zone 15
2.2.8.3 Contamination Reduction Zone 17
2.2.8.4 Support Zone - Post-decontamination Activities 21
2.2.9 "Contaminated Sample" Handling Procedure 22
2.3 Analysis 23
2.3.1 Binary Qualitative Analysis 23
2.3.2 Quantitative Area Analysis 24
3 Results and Discussion 25
3.1 Script 1: SOG Using Two Attendants and a Two-Step Outer Garment Spray-Brush
Decontamination Sequence (Two Tests) 25
3.1.1 Qualitative Analysis 25
3.1.2 Quantitative Analysis 28
IV
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3.2 Script 2: SOG Using Two Attendants with a Three-Step Outer Garment Spray-Brush-Rinse
Decontamination Sequence (One Test) 28
3.2.1 Qualitative Analysis 28
3.2.2 Quantitative Analysis 29
3.3 Script 3: SOG Using Three Attendants with a scripted Three-Step Outer Garment
Spray-Brush-Rinse Decontamination Sequence (Two Tests) 30
3.3.1 Qualitative Analysis 30
3.3.2 Quantitative Analysis 32
3.4 Script 4: SOG Using Two Attendants with a Scripted One-Step Outer Garment Water Mist
Spray Decontamination Sequence (Two Tests) 33
3.4.1 Qualitative Analysis 34
3.4.2 Quantitative Analysis 36
3.5 Script 5: SOG Using Two Attendants with a Scripted One-Step Outer Garment Cooking Oil
Spray Decontamination Sequence (Two Tests) 36
3.5.1 Qualitative Analysis 36
3.5.2 Quantitative Analysis 38
3.6 Script 6: SOG Using Two Attendants with a Scripted One-Step Outer Garment Water Mist
Spray Decontamination Sequence with Test Subjects Donning an Extra Inner Tyvek® Suit
(One Test) 39
3.6.1 Qualitative Analysis 39
3.6.2 Quantitative Analysis 40
3.7 Script 7: SOG Using Two Attendants with a Scripted One-Step Outer Garment Water
Mist Spray Decontamination Sequence with Test Subjects Donning Three Tyvek® Suits
(Two Tests) 41
3.7.1 Qualitative Analysis 41
3.7.2 Quantitative Analysis 43
3.8 "Contaminated Sample" Analysis 44
4 Quality Assurance 45
4.1 Sampling, Monitoring, and Analysis Equipment Calibration 45
4.2 Data Quality 45
4.3 Quality Assurance (QA)/Quality Control (QC) Checks 45
4.4 Acceptance Criteria for Critical Measurements 46
4.5 Data Quality Audits 46
4.6 QA/QC Reporting 46
5 Summary and Recommendations 47
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List of Figures
Figure 2.2-1. Representative test subject body areas used to identify contamination 7
Figure 2.2-2. Decon line testing design 8
Figure 2.2-3. Script 2 post-test evaluation pictures 11
Figure 2.2-4. Support zone area where Vitals A were acquired and paperwork was completed 12
Figure 2.2-5. PPE staging area 13
Figure 2.2-6. Test subject wearing Tyvek® inner suit and blue nitrile gloves, which represented
skin and street clothes 13
Figure 2.2-7. SZ background tent for pre-contamination UV evaluations 14
Figure 2.2-8. Test subject with Tychem® outer suit, facemask, gloves, and boots 14
Figure 2.2-9. Test subject's ID number fluorescing under UV light 15
Figure 2.2-10. Application of fluorescent powderto test subject 16
Figure 2.2-11. Contaminated hand of a test subject 16
Figure 2.2-12a. Sample drop-off bin 17
Figure 2.2-12b.Test subject making a sample drop 17
Figure 2.2-13. Hand wash (left) and boot rinse station (right) 18
Figure 2.2-14a. Test subject washing hands 18
Figure 2.2-14b. Test subject scrubbing boot 18
Figure 2.2-15. Test subject having outer suit sprayed down in the decon tent 19
Figure 2.2-16. Test subject being assisted with outer glove removal 19
Figure 2.2-17a.Test subject being assisted with removal of tape on suit's zipper prior to suit removal 20
Figure 2.2-17b.Test subject being assisted with removal of outer Tychem® suit 20
Figure 2.2-18. Test subject being assisted with mask removal 20
Figure 2.2-19. Hand and face wash setup 21
Figure 2.2-20. Support zone area where post-decontamination vitals (Vitals B) were acquired 22
Figure 2.3-1. Test script probability of occurrence (%) of cross-contamination 23
Figure 2.3-2. Front torso broad area cross-contamination 24
Figure 3.1-1a. Script 1, Test 1 occurrence (%) of cross-contamination 27
Figure 3.1-1b. Script 1, Test 2 occurrence (%) of cross-contamination 27
Figure 3.2-1. Script 2 occurrence (%) of cross-contamination 29
Figure 3.3-1 a. Script 3, Test 1 occurrence (%) of cross-contamination 32
Figure 3.3-1b. Script 3, Test 2 occurrence (%) of cross-contamination 32
Figure 3.4-1 a. Script 4, Test 1 occurrence (%) of cross-contamination 35
Figure 3.4-1b. Script 4, Test 2 occurrence (%) of cross-contamination 35
Figure 3.5-1 a. Script 5, Test 1 occurrence (%) of cross-contamination 38
vi
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Figure 3.5-1b. Script 5, Test 2 occurrence (%) of cross-contamination 38
Figure 3.6-1. Scripts occurrence (%) of cross-contamination 40
Figure 3.7-1a. Script 7, Test 1 occurrence (%) of cross-contamination 43
Figure 3.7-1b. Script 7, Test 2 occurrence (%) of cross-contamination 43
List of Tables
Table 2.1-1. Decontamination Equipment and Supplies 3
Table 2.1-2. Personal Protective Equipment 5
Table 2.2-1. Dosing Locations 15
Table 3.1-1. Script 1 Qualitative Analysis Occurrence of Cross-Contamination 26
Table 3.1-2. Script 1 Estimated Contaminated Surface Area (in2) 28
Table 3.2-1. Script 2 Qualitative Analysis Occurrence of Cross-Contamination 29
Table 3.2-2. Script 2 Estimated Contaminated Surface Area (in2) 30
Table 3.3-1. Scripts Qualitative Analysis Occurrence of Cross-Contamination 31
Table 3.3-2. Script 3 Estimated Contaminated Surface Area (in2) 33
Table 3.4-1. Script 4 Qualitative Analysis Occurrence of Cross-Contamination 34
Table 3.4-2. Script 4 Estimated Contaminated Surface Area (in2) 36
Table 3.5-1. Scripts Qualitative Analysis Occurrence of Cross-Contamination 37
Table 3.5-2. Script 5 Estimated Contaminated Surface Area (in2) 39
Table 3.6-1. Script 6 Qualitative Analysis Occurrence of Cross-Contamination 40
Table 3.6-2. Script 6 Estimated Contaminated Surface Area (in2) 41
Table 3.7-1. Script 7 Qualitative Analysis Occurrence of Cross-Contamination 42
Table 3.7-2. Script 7 Estimated Contaminated Surface Area (in2) 44
Table 4.4-1. QA/QC Sample Acceptance Criteria 46
List of Appendices
Appendix A Decontamination Line Standard Operating Guideline (SOG) "Long Term Biological
Decontamination Line"
Appendix B EPA Project Level C Decontamination and Doffing Script
Appendix C ARCADIS Test Participant Briefing on Human Subject Protection Issues
Appendix D Research Subject Information and Consent Form
Appendix E Overall Team Support and Responsibilities
Appendix F SOG Test Scripts
Appendix G Research Subject Post Test Questionnaire Form
VII
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List of Acronyms and Abbreviations
ARC ARCADIS
AT attendant
CBRN Chemical, Biological, Radiological, and Nuclear
CFR Code of Federal Regulations
CMAD CBRN Consequence Management Advisory Division
CRZ contamination reduction zone
CS control subject
DHS U.S. Department of Homeland Security
EPA U.S. Environmental Protection Agency
ERTG Emergency Response Technical Group
EZ exclusion zone
HAZMAT hazardous material
HSPD Homeland Security Presidential Directive
HSRP Homeland Security Research Program
ID identification
IRB Institutional Review Board
NHSRC National Homeland Security Research Center
OEM Office of Emergency Management
OSHA Occupational Safety and Health Administration
PPE personal protective equipment
QA quality assurance
QAPP Quality Assurance Project Plan
QC quality control
SOG standard operating guideline
Stdev standard deviation
SZ support zone
TS test subject
UNC University of North Carolina
USPHS U.S. Public Health Service
UV ultraviolet
VIM
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Executive Summary
This project supports the mission of the U.S. Environmental Protection Agency Office of Research and
Development's Homeland Security Research Program (HSRP) by providing information relevant to the
decontamination of areas contaminated as a result of a biological contamination incident. The primary
objective of this investigation was to evaluate and improve the effectiveness of each stage of the standard
operating guideline (SOG) that is used to provide guidance to EPA and contractors on decontamination of
personnel and samples in long-term response to biological contamination. The "Long Term Biological
Decontamination Line" SOG is used to prevent the spread of contamination beyond the exclusion zone
(EZ), often called the hot zone; to remove personal protective equipment (PPE) without exposing
personnel to contamination; and for verifying the effectiveness of procedures to ensure no contamination
is present on samples leaving the EZ.
The evaluation tests described in this report were conducted using a fluorescently dyed powder as a
surrogate for Bacillus anthracis (B. anthracis) spores. The use of non-pathogenic surrogate spores was
considered for this project, but abandoned due to concerns of cross-contamination and background
interference. The overall goal of the study was to identify any weaknesses in the SOG by detecting
potential portals of contamination. Modification of the procedures described in the SOG to eliminate any
weaknesses would reduce the chances of cross-contamination or spread of contamination outside the
EZ. If an identified weakness cannot be removed, emphasizing the weakness in the SOG would increase
awareness of the potential for cross-contamination. In an emergency response following an intentional
release of B. anthracis spores, it is important for first responders to know what procedures and PPE can
be used effectively to (1) contain contamination within the EZ, (2) protect responders from contamination,
and (3) prevent cross-contamination from responders and collected samples that could result in spread of
contamination into support areas.
This investigation focused on evaluating the decontamination (decon) line as a whole, not necessarily its
individual parts. For instance, if contamination was still present on the boots after the boots were
scrubbed, but the contamination remained on the doffed boots in the contamination reduction zone
(CRZ), often called the warm zone, and was not transferred to a test subject, then the decon line was a
success concerning the containment objective. While improvements to the SOG were not quantifiable,
steps were identified and defined in the protocols that proved successful at preventing or significantly
reducing cross-contamination in most situations.
Summary of Results
This study found that liquid and a scrub brush can be contaminant carriers. Therefore, unless a
completely effective liquid decontaminant (with immediate efficacy) is used, large amounts of liquid
should be avoided. The evaluation did not take into account, however, the use of disinfectants such as a
hypochlorite solution to reduce the biological contaminants that might be encountered in an actual event.
In addition, the results showed that the use of a secondary protective Tyvek® suit under the main Tyvek®
or Tychem® suit, along with several other measures such as applying a light mist or spray to the outside
of the primary suit to reduce reaerosolization and careful doffing of PPE with help from an attendant
wearing a fresh pair of gloves, can reduce cross-contamination or eliminate it completely. Even with the
best procedures, complete showering of personnel after leaving the decontamination line is
recommended. Finally, if samples are collected, special consideration should be given to the sample-
handling procedure to avoid and eliminate any cross-contamination from contaminated samples into any
ix
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areas outside decontamination and doffing areas. A specific multi-step sample-handling procedure
involving two sample handlers was found to be very effective for avoiding the transfer of contamination.
Modification of the "Long Term Biological Decontamination Line" SOG is recommended based on the
results of this work.
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1 Introduction
This project supports the mission of the U.S. Environmental Protection Agency (EPA) Office of Research
and Development's (ORD) Homeland Security Research Program (HSRP) by providing information
relevant to the decontamination of areas contaminated as a result of biological contamination incident.
Homeland Security Presidential Directive (HSPD)-10 tasked the U.S. Department of Homeland Security
(DHS) with coordinating the appropriate federal departments and agencies to develop comprehensive
plans that "provide for seamless, coordinated federal, state, local, and international responses to a
biological attack." As part of these plans, EPA, in conjunction with DHS and other agencies, is
"developing strategies, guidelines, and plans for decontamination of persons, equipment, and facilities" to
mitigate the risks of contamination following a biological weapons attack.
EPA's National Homeland Security Research Center (NHSRC) provides expertise and products that can
be widely used to prevent, prepare for, and recover from public health and environmental emergencies
arising from terrorist threats and incidents. NHSRC works with EPA's Office of Emergency Management
(OEM), CBRN (Chemical, Biological, Radiological, and Nuclear) Consequence Management Advisory
Division (CMAD), and OEM's Bioagent Workgroup within the Emergency Response Technical Group
(ERTG).
The Bioagent Workgroup, which comprises members from each of EPA's 10 Regions, compiled the "Long
Term Biological Decontamination Line" standard operating guide (SOG) (Appendix A) that was evaluated
for this project. This SOG provides guidance to EPA and contractors on decontamination of personnel
and samples in long-term responses to biological, chemical, and other toxic compound contamination.
This decontamination (decon) line SOG is used to prevent the spread of contamination beyond the
exclusion zone (EZ), to remove personal protective equipment (PPE) without exposing personnel to
contamination, and to ensure no contamination is present on samples leaving the EZ. Ongoing testing
and evaluation of the overall efficacy of the SOG is essential for identifying weaknesses and improving
the procedures.
1.1 Process
This work evaluated the "Long Term Biological Decontamination Line" SOG for sources of cross-
contamination or spread of contamination outside the EZ. Cross-contamination can occur any time there
is contact between the outer surface of PPE and an inner body surface. This contact can be either direct
or indirect through a carrier such as water or air. Contamination can then be spread by a responder
leaving the EZ after doffing PPE. Potential cross-contamination and spread of contamination outside the
EZ from a collected "contaminated sample" due to sample-handling procedures also was evaluated.
In this assessment of the SOG procedures, volunteer test subjects were dosed with a fluorescently dyed
powder as a surrogate for contamination that was used to track cross-contamination or the spread of
contamination outside the EZ. The use of non-pathogenic surrogate spores was considered for this
project, but abandoned due to concerns of cross-contamination and background interference. Some of
the volunteer test subjects were designated as control subjects (performed the same procedures as the
designated test subjects but were not dosed) or attendants (who performed assigned assistance roles in
the decon line and were not dosed). The test subjects were scanned with low-level ultraviolet (UV) light
before and after dosing with the fluorescent powder and then were given a dosed "sample" to carry into
the decon line. The test subjects proceeded through each step of the decon line, doffed their PPE, and
1
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were reevaluated with the UV light to detect any cross-contamination to an inner suit (simulating skin and
street clothes) that had occurred. The contaminated sample was carried and dropped off at a specified
point in the decon line for later evaluation of the sample-handling procedure and its possible role in the
spread of contamination.
It should be noted that this investigation focused on evaluating the decon line as a whole, not necessarily
its individual parts. For instance, if contamination was still present on the boots after the boots were
scrubbed, but the contamination was not transferred to the test subject and remained on the doffed boots
in the contamination reduction zone (CRZ), the decon line was a success with respect to the objectives of
the evaluation.
1.2 Project Objectives
In an emergency response following an intentional release of Bacillus anthracis (8. anthracis) spores, it is
important for first responders to know what procedures and PPE can be used effectively to (1) contain
contamination within the EZ, (2) protect responders from contamination, and (3) prevent cross-
contamination from responders and collected samples that could result in spread of contamination into
support areas. The primary objective of this project was to evaluate and improve, as necessary, the
effectiveness of the "Long Term Biological Decontamination Line" SOG used to decontaminate personnel
and samples during a long-term biological contamination event. The project aimed specifically to identify
potential portals of contamination in the decon line procedures. Elimination of those weaknesses by
procedural modifications of the SOG could substantially reduce the chance for cross-contamination or
spread of contamination into support areas. Further, emphasizing weaknesses that cannot be removed
could make users more aware of potential contamination issues.
While these test results do not quantify improvements or a lower chance of cross-contamination, they
qualitatively identify and define protocols that proved successful at reducing or preventing cross-
contamination in most situations. This report details the methods, study design, and results used in the
evaluation, as well as the weaknesses identified in the SOG protocol and the optimizations made to
reduce or prevent cross-contamination.
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2 Materials and Methods
Evaluation of the "Long Term Biological Decontamination Line" SOG was conducted in EPA's Fluid
Modeling Facility in Research Triangle Park, NC. Test subjects were dosed with a surrogate contaminant
and then performed activities in the decon line. During the procedures they also carried and dropped off
samples dosed with the surrogate contaminant. Seven scripts were evaluated beginning with the current
SOG (Appendix A). After performing a script, the participants were evaluated for contamination on their
inner suits (simulating their skin and street clothes) to identify modifications to the procedures that could
potentially reduce or eliminate cross-contamination or spread of contamination outside of designated
areas of the decon line. Each subsequent script tested the modifications derived from the previous script.
All test activities were documented during each round of testing via narratives in laboratory notebooks,
real-time data acquisition, photographs, and video recordings. This section describes the materials and
methods used in the testing, including equipment, setup, study design, and data analysis.
2.1 Equipment and Supplies
Evaluating the efficacy of the decon line SOG required an extensive setup with a variety of equipment
and a wide array of ancillary supplies. In addition, several types of PPE ensembles were needed for all
test scripts and for redundant layers of protection. All equipment and supplies used during the evaluation,
such as decontamination berms, sprayers, sponges, and brushes, were typical of products expected to
be used in an actual long-term decon line. Table 2.1-1 lists the decontamination equipment and supplies
used in this study.
Table 2.1-1. Decontamination Equipment and Supplies
Containment
Sprayers
Evaluation tents
Decon tent
UV lamps
UV flashlight
Fans
Surrogate
contaminant
Applicator brush
B Ij^MHihllMil
SPCC berm 3' x 3 'x 4"
Go-Go berm 6' x 6'
Duck pond 4' x 4'
Inflatable swimming pool 103" x 62.5"
1 -gallon bleach sprayer
4-gallon backpack sprayer
Barronett Blinds, Big Mike™ Blinds
6 watt
UVLED
Fluorescently dyed dry powder
Disposable applicator brush with metal
handle 3/4" long x 3/8" wide
907-030304
909-060604B
908-040404B
55192953
190360
190359
DAT 3030S
UVP600
BMINI8-365
1729K11
PXT-071LB
7237T83
Bj^^ffl^^^^l
Aire Industrial
Wai mart
D.B. Smith, The
Fountainhead Group, Inc.
Dunham's Sports
FSI, North America
Sirchie
Risk Reactor Inc.
McMaster-Carr
Risk Reactor Inc.
McMaster-Carr
Meridian, ID, USA
Durham, NC, USA
New York Mills, NY,
USA
Asheboro, NC,
USA
Sheffield Lake,
Ohio, USA
Youngsville, NC,
USA
Santa Ana, CA,
USA
Atlanta, GA, USA
Santa Ana, CA,
USA
Atlanta, GA, USA
Continued on next page
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Brush
Container
Polybag, inner
Polybag, outer
Bucket
Cooking oil spray
Vials
Hand and face
wash
Antiseptic
Wipes
Isopropyl alcohol
Blood pressure
monitor
Digital video
Duct tape
Description Part Number Company
General wash brush, Blue Hawk®
brand
250-mL graduated non-sterile
histology container with separate
screw cap
10" x 12" clear reclosable
3-gallon clear reclosable, Ziploc®
5-gallon food-grade plastic bucket
Pam original cooking spray
Borosilicate glass vials with screw cap
Foot-operated hand wash
91 % Isopropyl alcohol first aid
antiseptic
Premoistened with isopropyl
alcohol/deionized water
91% isopropyl alcohol solution by
volume
Automatic wrist blood pressure
monitor
Self-taking blood pressure monitor
Camcorders
General-purpose duct tape - silver
2.83" x 50 yards
226BHGM
6540
P0 165971
50640
6414403021
6414403031
IRC126-0020
Use-Yer-Foot
551780428
21910-110
Cat #2 16440
800824
800232
HMX-F90
1207805
Lowes, Inc.
Globe Scientific Inc.
Papermate
SC Johnson
Encore Plastics
ConAgra Foods, Inc.
Purologix Water Services,
Inc.
Turtle Run Farm
Wai mart
A1 Supply
CVS Pharmacy
CVS Corporation
Samsung
Nashua Trusted Tape
Products
Mooresville, NC,
USA
Paramus, NJ, USA
Racine, Wl, USA
Sandusky, OH,
USA
Omaha, NE, USA
Holly Springs, NC,
USA
Saxapahaw, NC,
USA
Durham, NC, USA
Raleigh, NC, USA
Durham, NC, USA
Woonsocket, Rl,
USA
BestBuy, Durham,
NC, USA
Franklin, KY, USA
A variety of PPE was used throughout the study. While the scripts varied the number and type of PPE
items used, all participants donned an inner Tyvek® coverall and first pair of disposable nitrile gloves,
which represented skin and street clothes. All PPE suits used in the evaluation, both inner and outer
suits, were either Tyvek® or Tychem® Class C HAZMAT suits. Level C protection is required when the
concentration and type of airborne substances is known and the criteria for using air purifying respirators
is met, as would be required when responding to an event such as that simulated in this evaluation (U.S.
EPA, Personal Protective Equipment, http://www2.epa.qov/emerqency-response/personal-protective-
equipment'). Table 2.1-2 lists the items of PPE used throughout the study.
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Table 2.1-2. Personal Protective Equipment
PPE Description Size
Outer suit
Inner suit (used to
represent skin)
Outer gloves
Suit gloves (taped
to outer suit)
Inner gloves (used
to represent skin)
Boots
Respirator
Tyvek® Class C
HAZMAT
Tyvek® Class C
HAZMAT
Tyvek® Class C
HAZMAT
Tychem® Class C
HAZMAT
Tychem® Class C
HAZMAT
Tyvek® Class C
HAZMAT
Tyvek® Class C
HAZMAT
Tyvek® Class C
HAZMAT
Purple long-cuff
Purple long-cuff
Green nitrile
Green nitrile
Blue nitrile
Blue nitrile
Blue nitrile
Heavy-duty
Face mask
XL
2X
MD
XL
2X
XL
2X
MD
XL
LG
LG
XL
LG
XL
LG
Various sizes
Various sizes
Part Number
DUPTY122SWHXLOO
DUPTY122SWH2XOO
DUPTY122SWHMDOO
DUPSL122BWHXLOO
DUPSL122BWH2XOO
DUPTY122SWHXLOO
DUPTY122SWH2XOO
DUPTY122SWHMDOO
32934-084
32934-082
19-130-3712
19-130-3713
82026-428
89107-332
89107-330
NA
AV-3000
Company Location
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
E. l.duPontde
Nemours and
Company
Kimberly-Clark
Corporation
Kimberly-Clark
Corporation
Showa Best Glove. Inc.
Showa Best Glove. Inc.
VWR International, LLC
Kimberly-Clark
Corporation
Kimberly-Clark
Corporation
AGM
Scott Safety
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Wilmington,
DE, USA
Dallas, TX,
USA
Dallas, TX,
USA
Menlo, GA,
USA
Menlo, GA,
USA
Radnor, PA,
USA
Dallas, TX,
USA
Dallas, TX,
USA
San Diego, CA,
USA
Monroe, NC,
USA
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2.2 Methods
The methods used to evaluate the effectiveness of the decon line SOG are detailed here. These include
participant roles, laboratory setup, test scripts, test procedures, and analysis methods.
2.2.1 Test Subjects
The test subjects for each evaluation were designated as one of three test subject types: (1) test subject
(dosed with contaminant), (2) control subject (not dosed), or (3) attendant (not dosed and provided
assistance to test and control subjects). All three types of test subject were trained to perform each step
of the SOG (Appendix A). Attendants were given step-by-step directions (Appendix B) for guiding the test
and control subjects through the decon line stations.
The total number of test subjects, control subjects, and attendants per tested script ranged from 7 to 15.
Either two or three attendants were used, depending on the script. Each participant was assigned a
unique four-character identification (ID) number based on their role in the test script (e.g., TS01, CS01,
AT01). All participants donned PPE, but only those designated as test subject were dosed with a
fluorescently dyed powder representing the contaminant, as described in Section 2.2.8.2; the attendants
and control subjects were not dosed. The control subjects proceeded through the decon line after the test
subjects, serving as an indicator of cross-contamination occurring from anything or anyone in the decon
line itself.
The bodies of each test subject, control subject, and attendant were divided into seven distinct sections
that were used as the evaluation areas:
• Head, neck, and shoulders
• Front torso: front central and side regions, including the thorax and abdomen but excluding the back,
neck, shoulders, and arms
• Left and right arms: region extending down each arm from the shoulder, excluding the shoulder but
including the arm pit
• Left and right legs: entire lower extremity of the body from the waist down, including feet, thighs, hips,
and buttocks
• Back: large posterior area of the body opposite the chest, rising from the top of the buttocks until
meeting (but excluding) the neck and shoulders
All results were analyzed and reported according to these section designations. A representative diagram
of these sections (Figure 2.2-1) was created to illustrate all reported results (Section 3) in a consistent
manner for easy comparison. This diagram is used in Section 3 to report the percentages of
contamination for test subjects, control subjects, and attendants for all evaluations.
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LJ
Figure 2.2-1. Representative test subject body areas used to identify contamination
2.2.2 Institutional Review Board
Because this project involved humans, approval was sought from the University of North Carolina (UNC)
at Chapel Hill Institutional Review Board (IRB) for human participants, which serves as the IRB for EPA
activities in Research Triangle Park, NC. The IRB submission was reviewed by UNC's Office of Human
Research Ethics, which determined that this project did not constitute human subjects research as
defined in the Code of Federal Regulations (45 CFR 46, 21 CFR 56, and 40 CFR 26) and therefore did
not require IRB approval. EPA reviewers did note, however, that attention to certain safety and health
aspects might still be required to protect the welfare of participants in this project, including adherence to
Occupational Safety and Health Administration (OSHA) requirements and careful, thorough training of
participants. All study participants were required to attend the Test Participant Briefing on Human
Protection Issues (Appendix C). In addition, they were provided with the Safety Data Sheet for the
fluorescently dyed powder that represented the contaminant and were required to sign a Research
Subject Information and Consent Form (Appendix D).
2.2.3 Setup
Figure 2.2-2 shows the setup used for evaluating the SOG. The testing area was divided into three zones:
support zone (SZ), exclusion zone (EZ), and contamination reduction zone (CRZ). Separate areas, or
stations, for carrying out discrete activities were defined within each zone. The SZ, shaded in blue in
Figure 2.2-2, surrounded the entire test area and contained specific areas for pre-contamination activities
at the start and post-decontamination activities at the end of the evaluation. The zones, stations, and
activities conducted in each area are described in detail in Section 2.2.8.
Two fans were in operation during the testing to help prevent cross-contamination. These fans were set to
simulate 3 mph prevailing winds. One was located in the SZ staging area that was used for pre-
contamination activities at the start of the evaluation and blew toward the EZ; the second fan was located
in the SZ outside of the outer garment doffing station (near ARC 5) and blew into the CRZ. Two video
cameras positioned in the SZ, one right outside the sample drop-off area and the other outside the outer
garment doffing station, continuously recorded the decontamination and doffing procedures. While each
test script varied with respect to procedural requirements (e.g., number of gloves, number and type of
coveralls, number of attendants), the zones and decontamination line flow shown in Figure 2.2-2 are
representative of all testing conducted.
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PPE
donning
area
Hand wash
and boot rinse
station
"Skin" suit
donning
PPE
staging
area
Decon tent
Boot removal
Outer garment
doffing station
-iHand and
'face wash
Camera Fan
Support
zone(SZ)
Exclusion
zone(EZ)
Contamination
reduction
zone (CRZ)
Unused
area
Figure 2.2-2. Decon line testing design
8
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2.2.4 "Contaminated Samples"
One of the goals of this project was to determine if cross-contamination occurred outside the EZ from
"contaminated samples," which were carried and dropped off by the test subjects and controls during the
evaluation. The samples comprised one 250-mL graduated non-sterile histology container with a separate
screw cap in a 10-inch by 12-inch clear, reclosable polybag. The test subjects' samples were dosed with
the fluorescent powder representing the contaminant following the procedure described in Section
2.2.8.2. Each sample was labeled "77-MMDDYY-(1-25)" where 77 was the contract work assignment
number; MMDDYYwas the month, day, and year; and (1-25) was the number of the sample kit used.
The labels were written on the bags with a permanent marker. The controls also carried sample bags, but
their bags were not dosed with the fluorescent powder. The procedures for handling the samples after
they were dropped off by the test subjects are described in Section 2.2.9.
2.2.5 Support Team
A support team of eight ARCADIS U.S., Inc. (ARC) contractor personnel (designated ARC 1 through
ARC 8) was spread across the test area. Each support team member had specific responsibilities such as
taking pre- and post-test vitals (called Vitals A and B, respectively), performing the dosing, and noting any
anomalies or vulnerabilities in the decon procedures. The specific responsibilities of each support team
member are detailed in Appendix E. To avoid cross-contamination, no one from the support team in the
SZ—the support zone surrounding the decon line that was used for pre-contamination activities at the
start and post-decontamination activities at the end of the evaluation—was allowed to participate in any
activities being performed in the EZ unless instructed to do so. Only ARC 2 and ARC 3 were allowed in
the EZ, where they remained until a test run was completed.
2.2.6 Test Scripts
Seven rounds of testing were conducted. Each round used a different script. Variations in the script were
introduced following each prior round of testing to eliminate identified weaknesses in the SOG, with the
goal of minimizing cross-contamination or spread of contamination from the EZ. Cross-contamination was
identified visually by the presence of fluorescent material on surfaces of the inner suit (i.e., the "skin"), on
the test samples, or in areas beyond the CRZ.
The seven rounds of testing that were evaluated are summarized below. Each script was modified by EPA
and the contractor personnel following evaluation of the results of the preceding testing script. Script 1
represents the existing SOG (Appendix A) being evaluated. Details of each of the seven scripts can be
found in Appendix F. One element that did not change from script to script was that the test subjects
washed their outer gloves and boots in the hand wash and boot rinse station upon entering the CRZ.
Script 1: SOG using two attendants and a two-step outer garment spray-brush decontamination
sequence (two tests)
In Script 1, the test subjects followed the existing SOG, as described in Appendix A, using two
attendants. The first attendant's sole function was to wash down the test subject and remove their
boots, while the second attendant helped the test subject doff their face mask and outer suit.
Script 2: SOG using two attendants with a three-step outer garment spray-brush-rinse
decontamination sequence (one test)
Script 2 followed the Script 1 procedure, with the first attendant adding a rinse step following
the test subject's outer suit spray-brush procedure. The rinse step was added to determine if it
had a positive outcome in reducing cross-contamination during the doffing step.
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Script 3: SOG using three attendants with a scripted three-step outer garment spray-brush-rinse
decontamination sequence (two tests)
Script 3 followed the Script 2 procedure but with the addition of a third attendant to the decon
line to evaluate whether extra doffing assistance would reduce contamination. The attendants
were briefed prior to testing on their role of simulating real-life scenarios without directions
from outside support personnel. Attendant 1 was charged with directing the test subjects
through the decon station. Attendants 1 and 2 performed the three-step decontamination
sequence. Attendant 3 assisted the test subjects with doffing their outer garments (gloves,
mask, and coverall). The duties of each attendant were displayed on posters at the points of
performance in the decon line to help the attendants carry out their roles.
Script 4: SOG using two attendants with a scripted one-step outer garment water mist spray
decontamination sequence (two tests)
Script 4 followed the Script 2 procedure, but Attendant 1 used only a one-step light water
spray from top down on the outer garment including the boots. The attendants were briefed
prior to testing on their role of simulating real-life scenarios without directions from outside
support personnel. Attendant 1 also directed test subjects through the decon station.
Attendant 2 assisted the test subjects with doffing their outer garment. The scripted duties of
each attendant were displayed on posters at the point of performance in the decon line to help
the attendants carry out their roles.
Script 5: SOG using two attendants with a scripted one-step outer garment cooking oil spray
decontamination sequence (two tests)
Script 5 followed the Script 4 procedure, but Attendant 1 used cooking oil spray (in place of the
water spray) from top down on the outer garment including the boots. Cooking spray oil was
suggested as a method to reduce reaerosolization of contaminants during the doffing
procedure.
Script 6: SOG using two attendants with a scripted one-step outer garment water mist spray
decontamination sequence with test subjects donning an extra inner Tyvek® suit (one
test)
Script 6 followed the Script 4 procedure, but test subjects wore three coveralls (two inner
Tyvek® coveralls and one outer Tychem® coverall). This test was designed to determine if an
added layer of protection reduces test subject exposure to contamination.
Script 7: SOG using two attendants with a scripted one-step outer garment water mist spray
decontamination sequence with test subjects donning three Tyvek® suits and no outer
Tychem® coverall (two tests)
Script 7 followed the Script 6 procedure with test subjects wearing three Tyvek® coveralls (no
Tychem® coverall). This test was designed to determine if replacing the expensive, waterproof
Tychem® suit with less expensive, more breathable Tyvek® would affect the protectiveness to
inner suit contamination.
10
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2.2.7 Test Facility Evaluation after Scripts 1 and 2
Following evaluation of the results of the Script 2 quantitative analysis, questions arose as to whether the
test facility itself could be contributing to the observed contamination. Therefore, it was decided that a
systematic evaluation of the test facility should be performed prior to developing and initiating Script 3 to
determine the spread, if any, of contamination inside and outside the decontamination stations. The exit
flap of the decon tent, the chair where test subjects were seated for outer garment removal, and the SZ
Vitals B table were evaluated. The results of the evaluation showed that, even after decontamination,
each area showed signs of cross-contamination, as illustrated in Figure 2.2-3. Thus, instructions were
given thereafter to cover the tables with disposable Tyvek® materials at the start of each testing sequence
to reduce or eliminate cross-contamination of clean areas and prevent migration of contamination to
support areas. Additionally, movement of test subjects and support personnel was strictly monitored. The
entire test facility area was cleaned and reassessed to remove any background contamination. The test
facility was reevaluated daily, and no significant contamination was noted after Script 2.
Exit flap of decon tent
Outer garment removal chair
Vitals B table Footprint outside SZ evaluation tent
Figure 2.2-3. Script 2 post-test evaluation pictures
11
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2.2.8 Decon Line Evaluation Procedures
The following subsections describe the activities conducted in each zone as the test subjects advanced
through the decon line evaluation scripts. The overall evaluation process for all scripts was an initial UV
scan, followed by each participant performing an assigned role in each step of the SOG, and then a final
UV scan to determine the location and extent of cross-contamination that occurred in the decon line.
Refer to Figure 2.2-2 for the locations of each zone and station.
During the tests, two video cameras continuously recorded the decon line activities. In addition, ARC 4,
positioned just outside the sample drop-off area near the first video camera, and ARC 5, positioned
outside the outer garment doffing station near the second camera, noted any anomalies or vulnerabilities
during the performance of the decontamination procedures. A post-test questionnaire (Appendix G) was
also completed by the participants at the end of the testing. Responses to this questionnaire, along with
photographs and video recordings and the notes taken by the support team, aided in the evaluation of the
decon line procedures and became part of the test results.
2.2.8.1 Support Zone - Pre-contamination Activities
ARC 1 had responsibility for the SZ pre-contamination activities at the start of the evaluation where each
test subject was greeted, briefed on the protocol and PPE donning procedures, and assigned a unique
(ID) number. Then pre-test vital signs (Vitals A)—blood pressure and pulse—were acquired, and the test
subjects completed their paperwork (Figure 2.2-4).
Figure 2.2-4. Support zone area where Vitals A were acquired and paperwork was completed
Participants also donned their PPE in the SZ and underwent initial UV evaluations as a background
contamination check. As show in Figure 2.2-5, a PPE staging area was set up in the SZ to make the PPE
readily available and accessible for each test.
12
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Figure 2.2-5. PPE staging area
A strict protocol for donning PPE was employed so that all personnel were representative of hazardous
materials (HAZMAT) workers in the field, which included taping all seams with duct tape. The test
subjects, control subjects, and attendants first donned an inner Tyvek® coverall and initial pair of blue
disposable nitrile gloves (different color gloves were used to distinguish inner and outer PPE layers and
the extra set of gloves when called for by the script). This inner suit represented skin and street clothes
(Figure 2.2-6). The gloves were taped to the coverall. The participants, wearing just the inner suit, then
entered the background tent (Figure 2.2-7) for evaluation by scanning with a UV LED flashlight for any
initial contamination.
Figure 2.2-6. Test subject wearing Tyvek® inner suit and blue nitrile gloves, which represented
skin and street clothes
13
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Figure 2.2-7. SZ background tent for pre-contamination UV evaluations
After the initial UV assessment of the "skin" PPE, the participants donned their outer PPE garments,
including green disposable nitrile gloves, heavy-duty boots, and face masks (Figure 2.2-8). All seams
were taped with duct tape, including a large bib covering the area under the chin between the face mask
and the suit. The participants were then reevaluated in the SZ background tent with the UV light. The ID
number for each participant was written on each protective suit. Figure 2.2-9 shows the ID number
fluorescing under the UV light.
Figure 2.2-8. Test subject with Tychem® outer suit, facemask, gloves, and boots
14
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Figure 2.2-9. Test subject's ID number fluorescing under UV light
2.2.8.2 Exclusion Zone
After donning PPE and being UV scanned, the attendants immediately took their places in the decon line
as specified by the test script, and test and control subjects proceeded to the EZ. In this zone, ARC 2
used an applicator brush to apply approximately 0.2 gram of the fluorescent powder surrogate
contaminant to five discrete locations (Table 2.2-1) on each test subject (control subjects were not
dosed), as illustrated in Figure 2.2-10. These locations were selected to provide a cross-section of
potentially contaminated areas that could occur under field conditions. The test subjects then entered the
dosing tent where they were again evaluated, by ARC 3, using one or more 6-watt UV lamps.
Figure 2.2-11 shows the contaminated hand of a test subject. The controls bypassed the dosing tent.
Table 2.2-1. Dosing Locations
Location
1
2
3
4
5
Dosed Locations
Outside efface mask
Palm of right-hand glove
Left shoulder
Right hip
Inner side of left boot
15
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Figure 2.2-10. Application of fluorescent powder to test subject
Figure 2.2-11. Contaminated hand of a test subject
The "contaminated sample" was also dosed in the EZ. ARC 2 dosed the outside of the bag just below the
label with approximately 0.05 g of the fluorescent powder. The amount of powder applied was determined
gravimetrically, weighing the brush before and after application. These dosed samples were placed on a
rack just outside the dosing room but still within the EZ. After being dosed and evaluated, the test
subjects exited the dosing room and each picked up one of the dosed samples before proceeding to the
next step in the decon line.
16
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2.2.8.3 Contamination Reduction Zone
Test and control subjects proceeded through the following CRZ areas:
1. Sample drop-off
2. Hand wash and boot rinse station
3. Decon tent
4. Boot removal
5. Outer garment doffing station
6. Hand and face wash
Sample drop-off
The test subjects advanced to an area designated for sample drop-off, where ARC 4 instructed them to
place their samples in the bin located there. Figure 2.2-12a shows the sample drop-off bin, and
Figure 2.2-12b shows a test subject dropping off a sample.
Figure 2.2-12a. Sample drop-off bin
Figure 2.2-12b.Test subject making a sample drop
Hand wash and boot rinse station
The next stop was the hand wash and boot rinse station (Figure 2.2-13) located next to where the
samples were dropped off. At this station, the test and control subjects were instructed by ARC 4 to wash
their hands, including between the fingers. They were then directed to place one foot into a collection
berm and to scrub each boot, aiming the brush down and away. The same action was performed on the
other boot. Figure 2.2-14a shows a test subject washing their hands and Figure 2.2-14b shows the boot
scrubbing.
17
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Figure 2.2-13. Hand wash (left) and boot rinse station (right)
Figure 2.2-14a. Test subject washing hands
Figure 2.2-14b. Test subject scrubbing boot
Decontamination tent
Next the test and control subjects were told to step from the berm into a second berm inside the decon
tent. The decon tent was used for several decontamination methods including spraying (Figure 2.2-15),
brushing, and rinsing by attendants, depending on the details of the test script.
18
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Figure 2.2-15. Test subject having outer suit sprayed down in the decon tent
Boot removal
The test and control subjects then stepped into another area inside the decon tent that was designated
for boot removal. Here an attendant assisted them with removing their boots.
Outer garment doffing station
After boot removal, the test and control subjects were directed to step out of the opposite side of the
decon tent into the outer garment doffing station. An attendant assisted with removal of the test subjects'
outer gloves (Figure 2.2-16), outer suit (Figures 2.2-17a and b), and face mask (Figure 2.2-18).
Figure 2.2-16. Test subject being assisted with outer glove removal
19
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Figure 2.2-17a.Test subject being assisted with Figure 2.2-17b.Test subject being assisted with
removal of tape on suit's zipper prior to suit removal of outer Tychem® suit
removal
Figure 2.2-18. Test subject being assisted with mask removal
(The suit pictured on the left represents the inner "skin" layer)
20
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Hand and Face Wash
The subjects proceeded next to an area in the decon line where they were instructed to doff their
secondary gloves if worn for the script and to wash their hands and face with a soap solution followed by
a water rinse (Figure 2.2-19).
Figure 2.2-19. Hand and face wash setup
2.2.8.4 Support Zone - Post-decontamination Activities
At the conclusion of the decon line procedures, the test subjects, control subjects, and attendants moved
from the CRZ into the SZ where ARC 6 took their post-decontamination blood pressure and pulse
(Vitals B) (Figure 2.2-20). After having their vitals checked, the participants entered the evaluation tent,
where ARC 7 performed the post-decontamination evaluation using 6-watt UV lamps while dictating notes
to ARC 6 who was outside. Areas of fluorescence were outlined with a marker on the undergarment by
ARC 7, who also provided estimates of contaminated areas in inches squared (in2). The participants then
stepped outside of the evaluation tent where they removed their inner gloves and inner suit (mimicking
the skin) and handed them to ARC 7. ARC 7 bagged these PPE items and noted the test subject ID on
the bag. Participants were evaluated under UV light one final time in their street clothes and then were
asked to wash off any fluorescent material present on their hands and face. ARC 6 and ARC 7 donned
new pairs of gloves between each test subject evaluation.
21
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Figure 2.2-20. Support zone area where post-decontamination vitals (Vitals B) were acquired
2.2.9 "Contaminated Sample" Handling Procedure
On the day after each test script was completed, all samples that had been dropped off by the test
subjects and controls were put through a standard sample-handling procedure devised to eliminate any
cross-contamination. This sample-handling procedure involved two sample handlers (Samplers A and B)
who followed the specific steps listed below:
Sampler A
1. Don a new pair of gloves before touching any parts of the inner sample bag.
2. Spray the outside of the sample bag using a spray bottle containing 91% isopropyl alcohol
solution by volume.
3. Using a paper towel, wipe down the outside of the inner sample bag and the lip.
4. When Sampler B is ready, insert the wiped down bag into the 3-gallon bag outer bag held
open by Sampler B.
Sampler B
1. Don a new pair of gloves.
2. Open a 3-gallon outer Ziploc® bag without touching the outside of the bag for Sampler A to
insert the wiped down sample bag.
3. Press the 3-gallon bag to remove air and seal.
4. Wipe down the outside of the 3-gallon bag, including the lip of the zipper, using a pre-
moistened wipe containing 70% reagent-grade isopropyl alcohol and 30% reagent-grade
deionized water.
5. Don a new pair of gloves.
6. Repeat the wipe-down of the 3-gallon bag, including the lip of the zipper, using a new alcohol
wipe.
22
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2.3 Analysis
The test subjects, control subjects, and attendants were evaluated using two approaches for each test
script to determine the presence of cross-contamination on the inner Tyvek® suits simulating their skin.
The two approaches, a binary qualitative approach and a quantitative approach, were used to evaluate
the effectiveness of each test script in reducing or eliminating cross-contamination from the outer suit to
the inner suit of the test subjects, control subjects, and attendants.
2.3.1 Binary Qualitative Analysis
The first approach used was a binary qualitative evaluation. In this approach, either a 0 (no contaminant
detected) or a 1 (contaminant observed) was applied for the contamination found on each region of the
participant's body. The probability of occurrence (%) of cross-contamination for each test script was
calculated by taking the average of the contamination for that region of the body for all test subjects,
control subjects, or attendants who participated in that testing sequence. The resulting average
probability of occurrence (%) and standard deviation (stdev) were used to evaluate the effectiveness of
each test script. The results were represented graphically on a figure showing results for all test
participants in a testing sequence. In order to make general comparisons at a glance, the figures used a
percentage of shading corresponding to the percentage of contamination found in that region of the body
(see Section 2.2.1 for a detailed description of the regions). Figure 2.3-1 illustrates the probability of
occurrence (%) of cross-contamination for an example test script. Results for all test scripts in Section 3
are represented in this manner.
Head, neck,
and shoulders
80%
Left arm
0%
Back
Right leg 80% 60% Left leg
Figure 2.3-1. Test script probability of occurrence (%) of cross-contamination
23
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2.3.2 Quantitative A rea A nalysis
The second approach for evaluating cross-contamination consisted of estimating the area that
demonstrated increased fluorescence as a result of contamination on the innermost suit or "skin". When
applicable, the area estimate was of the broad area affected during a single event rather than of individual
splatters, as seen in Figure 2.3-2.
Figure 2.3-2. Front torso broad area cross-contamination
24
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3 Results and Discussion
Both qualitative and quantitative analyses were conducted on the inner suit used to represent the skin for
each of the seven scripts to determine if the test subjects were protected from contamination and if they
were potential vectors of cross-contamination into any support areas outside the EZ. Note the results do
not take into account any microbial population reduction potential that would occur under actual field
conditions where effective sporicidal agents, such as 0.5% hypochlorite solution, would be used in the
decontamination process. Script variations were introduced following each round of testing. These
variations were based on the evaluations from the previous testing round with the ultimate goal of
improving individual SOG procedures to minimize cross-contamination. The following subsections present
the results of each script evaluation and a discussion of the reasoning and motivations that led to the
script variations. Also briefly discussed here are the results of the "sample" decontamination procedures.
As explained in Section 2, for the binary qualitative evaluations either a 0 (contaminant detected) or a
1 (contaminant observed) was applied to each region of the participant's body. These values were then
averaged and represented graphically. For the qualitative evaluations, the participants' inner suits were
visually examined and areas of contamination were outlined and measured and are reported here in
inches squared (in2).
3.1 Script 1: SOG Using Two Attendants and a Two-Step Outer Garment Spray-
Brush Decontamination Sequence (Two Tests)
Script 1: This test script was conducted to reflect the current version of the SOG, which uses two
attendants. The first attendant's function was to perform physical removal of the gross contaminants
from the outer suits of the test subjects. A soap and water washdown was followed by brushing off the
outer suit. This attendant also helped the test subjects remove their boots. The second attendant's
role was to help the test subjects doff their outer suit, outermost layer of gloves, and face mask. The
test script was run in duplicate, with different attendants, to determine if the techniques of the
attendants had any effect on amount of cross contamination.
3.1.1 Qualitative A nalysis
The qualitative results for this test script are listed in Table 3.1-1 for Test 1 (five test subjects and two
attendants) and Test 2 (four test subjects and two attendants). Figures 3.1-1 a and 3.1-1b graphically
represent the probability of occurrence (%) of cross-contamination for each region of the body in Tests 1
and 2, respectively. These results show a high probability of cross-contamination for all regions of the
body for both the test subjects and the attendants. A 100% chance of contamination of the front torso
(labeled "front" in all results tables and figures) is shown for this script, which is the region where the
attendants are most exposed to contact with the test subjects during the doffing process. Test 2 shows
that the attendants' contamination was reduced from all of the evaluated regions to only one area of the
body (left arm). Significant variation was observed among attendants performing the same doffing
technique (e.g., speed at which procedure was performed, attention to procedural details). The
improvement observed in Test 2 can possibly be attributed to a better doffing technique used by the
second pair of attendants.
25
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The results show that the spread of contamination can be very lame, more than 2 ft2 in some regions of
the body for certain test subjects. The results were consistent with reports by the test subjects that the
soap and water being used for decontamination was penetrating the suit, probably at the taped seams at
the neck and the gloves, and carrying contaminant particles into the inner skin suit. This liquid penetration
might also be exacerbated during the brushing process. Note that the brush used to remove the gross
contamination was reused on each test subject, thus providing a vehicle for cross-contamination among
test subjects.
Although the Test 2 attendants came out cleaner than the Test 1 attendants, no correlation can be drawn
on the spread of contamination by the attendants from one test subject to another. The change in
attendants seemed to have a marginal effect, if any, in reducing or alleviating the cross-contamination
among the test subjects.
Table 3.1-1. Script 1 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Testl
TS31
TSOO
TS02
TS79
TS62
AT10
AT32
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
0
0
1
1
1
20
45
100
0
1
1
1
1
1
1
1
100
0
100
0
1
0
1
1
1
1
1
80
45
100
0
0
1
0
1
0
1
0
40
55
50
71
0
1
1
1
1
1
0
80
45
50
71
0
0
1
1
1
1
0
60
55
50
71
1
1
1
0
1
1
0
80
45
50
71
Test 2
TS10
TS79
TS02
TS26
AT62
ATOO
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
1
0
0
1
0
0
50
58
0
0
1
1
1
1
0
0
100
0
0
0
1
0
1
1
0
1
75
50
50
71
1
1
1
1
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
25
50
0
0
0
1
1
0
0
0
50
58
0
0
26
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Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Script 1 Overall
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
33
GO
50
58
100
0
50
58
78
44
75
50
67
50
25
50
44
53
25
50
44
53
25
50
67
44
25
50
Test Subjects
Attendants
Figure 3.1-1 a. Script 1, Test 1 occurrence (%) of cross-contamination
Test Subjects
Attendants
Figure 3.1-1b. Script 1, Test 2 occurrence (%) of cross-contamination
27
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3.1.2 Quantitative A nalysis
The quantitative areas for each region of the body for each test subject and attendant are presented in
Table 3.1-2.
Table 3.1-2. Script 1 Estimated Contaminated Surface Area (in2)
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Total
Testl
TS31
TSOO
TS02
TS79
TS62
AT10
AT32
NO*
NO
NO
NO
36
64
16
21
32
6
1
1
1
10
2
NO
3
1
6
7
28
NO
4
NO
4
NO
8
30
NO
132
2
1
1
4
NO
NO
NO
10
1
1
1
NO
15
36
79
NO
1
1
NO
38
204
100
8
46
86
84
Test 2
TS10
TS79
TS02
TS26
AT62
ATOO
29
NO
NO
48
NO
NO
6
144
240
12
NO
NO
4
NO
16
3
NO
2
18
120
144
64
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
80
NO
NO
NO
NO
348
16
NO
NO
NO
57
612
496
127
NO
2
*NO: contamination not observed
3.2 Script 2: SOG Using Two Attendants with a Three-Step Outer Garment
Spray-Brush-Rinse Decontamination Sequence (One Test)
Script 2: This test script was similar to Script 1 but with an added rinse step following the test subject's
surface spray-brush procedure.
3.2.1 Qualitative A nalysis
The qualitative results for Script 2 are listed in Table 3.2-1 (four test subjects, one control subject, and two
attendants). These results show a high probability of cross-contamination for all regions of the body for
both the test subjects and the attendants. As was seen for Script 1, a 100% chance of contamination of
the front torso was seen. This is the region that is most exposed to contact with the attendant during the
doffing process and has potential for contamination due to leaking at the taped neck area. The addition of
the rinse step did not seem to reduce the cross-contamination of the front torso for the test subjects,
control subject, or attendants as illustrated in Figure 3.2-1.
28
-------
Table 3.2-1. Script 2 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
TS10
TS02
TS62
TSOO
CS26
AT90
AT79
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
Head, Neck, and Shoulders
0
0
0
0
0
0
0
0
0
0
0
Front
1
1
1
1
1
1
1
100
0
100
0
Left Arm
1
1
1
1
0
0
0
100
0
0
0
Right Arm
1
0
0
0
0
0
0
25
50
0
0
Back
0
0
0
0
0
0
1
0
0
50
71
Left Leg
0
1
0
1
0
0
0
50
58
0
0
Right Leg
1
0
0
0
0
0
0
25
50
0
0
Test Subjects
Control Subject
Attendants
Figure 3.2-1. Script 2 occurrence (%) of cross-contamination
3.2.2 Quantitative Analysis
The addition of the rinse step in the decontamination process for this script seems to have had a minimal
effect on reducing cross-contamination for most of the test subjects and the attendants (Table 3.2-2). The
spread of contamination over relatively large surfaces observed in this script and in Script 1 suggests the
likelihood of cross-contamination due to liquid penetration through vulnerabilities of the suit (e.g., seams,
zipper, taped areas), the reused brush among test subjects, and/or the doffing process.
29
-------
Table 3.2-2. Script 2 Estimated Contaminated Surface Area (in2)
Test Subject ID
TS10
TS02
TS62
TSOO
CS26
AT90
AT79
Head, Neck, and Shoulders
NO*
NO
NO
NO
NO
NO
NO
Front
12
120
80
36
16
120
100
Left Arm
55
206
25
240
0
0
0
Right Arm
8
NO
NO
NO
NO
NO
NO
Back
NO
NO
NO
NO
NO
NO
4
Left Leg
NO
96
NO
10
NO
NO
NO
Right Leg
8
NO
NO
NO
NO
NO
NO
Total
83
422
105
286
16
120
104
*NO: contamination not observed
3.3 Script 3: SOG Using Three Attendants with a scripted Three-Step Outer
Garment Spray-Brush-Rinse Decontamination Sequence (Two Tests)
Script 3: This script followed the Script 2 testing procedure with the addition of a third attendant.
Attendants 1 and 2 were housed inside the decon tent, while Attendant 3 was in charge solely of
helping the test subjects in the outer garment doffing station.
Note: After Scripts 1 and 2, questions arose about the facility itself possibly contributing to
contamination. An evaluation of the entire test facility (see Section 2.2.7) was conducted prior to the
Script 3 evaluation.
3.3.1 Qualitative A nalysis
The qualitative results for this test script are listed in Table 3.3-1 for Test 1 (five test subjects and three
attendants) and Test 2 (four test subjects and three attendants). The probability of occurrence (%) of
cross-contamination for each region of the body is illustrated in Figures 3.3-1 a and 3.3-1 b for Tests 1 and
2, respectively. The addition of a third attendant as well as a full facility cleaning, movement restrictions,
and disposable covering on work surfaces did not seem to decrease the probability of cross-
contamination for all regions of the body for either test subjects or attendants. The most probable zone of
the body for contamination was still the front torso region due to vulnerabilities of the suit, which include
the zipper and taped areas.
30
-------
Table 3.3-1. Script 3 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Testl
TS31
TSOO
TS63
TS06
TS62
AT50
AT79
AT02
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
80
45
67
58
0
1
1
1
0
0
0
1
60
55
33
58
0
0
0
0
0
1
0
0
0
0
33
58
0
0
0
1
0
0
0
0
20
45
0
0
0
0
0
1
0
0
0
0
20
45
0
0
1
1
1
0
0
0
0
0
60
55
0
0
Test 2
TSOO
TS79
TS50
TS02
AT63
AT62
AT31
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
1
1
1
0
0
0
0
75
0
0
0
1
0
1
1
1
1
0
75
58
67
58
1
1
1
1
1
0
0
100
0
33
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
1
50
58
33
58
0
0
0
0
0
1
0
0
0
33
58
Script 3 Overall
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
33
50
0
0
78
44
67
52
78
44
33
52
0
0
17
41
11
33
0
0
33
50
17
41
33
50
17
41
31
-------
Test Subjects
Attendants
Figure 3.3-1 a. Script 3, Test 1 occurrence (%) of cross-contamination
r~
33% 33%
Test Subjects
Attendants
Figure 3.3-1b. Script 3, Test 2 occurrence (%) of cross-contamination
3.3.2 Quantitative Analysis
The results of the quantitative analysis (Table 3.3-2) for this script confirm the fact that the spread of
contamination was not reduced by adding a third attendant helping with the doffing process and was likely
the result of the decon process (with suit vulnerabilities being the primary culprit and possibly the reuse of
the brush for each test subject).
32
-------
The spreading of contamination over relatively large surface areas suggests that the three-step spray-
brush-rinse decontamination process might have been caused by liquid penetrating the outer suit to the
skin through vulnerabilities of the suit (e.g., seams, zipper, taped areas) as reported by some of the test
subjects on the post-test questionnaire. TSOO reported feeling that when his arms were raised, water
came down both sides of his arms towards his legs during the spraying process. TS79 reported water
running under his armpits.
Table 3.3-2. Script 3 Estimated Contaminated Surface Area (in2)
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Total
Testl
TS31
TSOO
TS63
TS06
TS62
AT50
AT79
AT02
NO*
NO
NO
NO
NO
NO
NO
NO
195
225
240
12
NO
NO
100
1
NO
48
36
304
NO
NO
NO
1
NO
NO
NO
NO
NO
12
NO
NO
NO
NO
NO
6
NO
NO
NO
NO
NO
NO
NO
54
NO
NO
NO
NO
15
504
240
NO
NO
NO
NO
NO
210
777
516
376
0
12
100
2
Test 2
TSOO
TS79
TS50
TS02
AT63
AT62
AT31
5
12
3
NO
NO
NO
NO
8
NO
82
2
6
2
NO
34
72
12
1
1
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
2
3
NO
NO
NO
3
NO
NO
NO
NO
NO
2
NO
47
86
100
3
7
4
3
*NO: contamination not observed
3.4 Script 4: SOG Using Two Attendants with a Scripted One-Step Outer
Garment Water Mist Spray Decontamination Sequence (Two Tests)
Script 4: This script followed the Script 2 procedure, but Attendant 1 used only a one-step light water
mist from top down on the outer garment including the boots, whereas Script 2 had a more involved
spray-brush technique that focused on hard-to-reach areas such as armpits, backs of knees, inside
arms, between fingers, etc. Script 4 was designed to reduce contaminant reaerosolization rather than
to remove the contaminant.
33
-------
3.4.1 Qualitative Analysis
The qualitative results for this test script are listed in Table 3.4-1 for Test 1 (three test subjects, one
control subject, and two attendants) and Test 2 (three test subjects, one control subject, and two
attendants). The probability of occurrence (%) of cross-contamination for each region of the body is
illustrated in Figures 3.4-1 a and 3.4-1b for Tests 1 and 2, respectively. The elimination of the spraying
and brushing steps seems to reduce the probability of cross-contamination of the different regions of the
test subjects, control subject, and attendants. The spraying and brushing might have increased the
chances of the water/soap solution infiltrating the outer ensemble of Tychem® suit, gloves, face mask,
and tape, thereby contaminating the inner suit (skin). The front torso region remains the most vulnerable
area for contamination for this script.
Table 3.4-1. Script 4 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Testl
TS62
TS31
TS79
CS63
AT02
AT50
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
1
1
0
0
1
67
58
50
71
1
1
0
0
0
0
67
58
0
0
0
1
0
1
1
1
33
58
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
33
58
0
0
0
0
0
0
0
0
0
0
0
0
Test 2
TS61
TS77
TS52
CS62
AT31
AT79
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
1
0
1
0
33
58
50
71
0
1
0
0
0
0
33
58
0
0
0
1
0
0
0
0
33
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
33
58
0
0
1
0
0
0
0
0
33
58
0
0
34
-------
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Script 4 Overall
Test Subject Average (%)
Test Subject Stdev
Control Subject Average (%)
Control Subject Stdev
Attendant Average (%)
Attendant Stdev
50
55
0
0
50
58
50
55
0
0
0
0
33
52
50
71
50
58
0
0
0
0
0
0
0
0
0
0
0
0
33
52
0
0
0
0
17
41
0
0
0
0
Test Subject
Control Subject
Attendant
Figure 3.4-1 a. Script 4, Test 1 occurrence (%) of cross-contamination
Test Subject
Control Subject
Attendants
Figure 3.4-1 b. Script 4, Test 2 occurrence (%) of cross-contamination
35
-------
3.4.2 Quantitative Analysis
The results of the quantitative analysis (Table 3.4-2) for this script confirm the reduction of the spread of
contamination that resulted from switching from a vigorous spraying and brushing decontamination
approach to a more gentle water mist. This appears to have been effective in keeping the contamination
from spreading.
Table 3.4-2. Script 4 Estimated Contaminated Surface Area (in2)
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Total
Testl
TS62
TS31
TS79
CS63
AT02
AT50
NO*
1
6
NO
NO
3
28
9
NO
NO
NO
NO
NO
1
NO
4
4
1
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
16
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
28
27
6
4
4
4
Test 2
TS61
TS77
TS52
CS62
AT31
AT79
NO
NO
12
NO
79
NO
NO
10
NO
NO
NO
NO
NO
1
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
1
NO
NO
NO
NO
NO
1
NO
NO
NO
NO
NO
2
11
12
NO
79
NO
*NO: contamination not observed
3.5 Script 5: SOG Using Two Attendants with a Scripted One-Step Outer
Garment Cooking Oil Spray Decontamination Sequence (Two Tests)
Script 5: This script followed the Script 4 procedure, but Attendant 1 used spray cooking oil (canola
oil) instead of water to spray from top down on the outer garment including the boots. Note: Spray
cooking oil was suggested as a potential expeditious field method to reduce reaerosolization from the
outer suit.
3.5.1 Qualitative A nalysis
The qualitative results for this test script are listed in Table 3.5-1 for Test 1 (three test subjects, one
control subject, and two attendants) and Test 2 (four test subjects and two attendants). The probability of
occurrence (%) of cross-contamination for each region of the body is illustrated in Figures 3.5-1 a and
3.5-1 b for Tests 1 and 2, respectively. The use of cooking oil seems to have the same positive effect as
the light water spray on reducing the probability of contamination on different regions of the test subjects,
36
-------
control subject, and attendants. The front torso region remains the primary vulnerability for contamination
for this script.
Table 3.5-1. Script 5 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Testl
TS62
TS77
TS31
CS79
AT52
AT61
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
1
0
0
0
0
0
33
58
0
0
1
1
1
0
0
1
100
0
50
71
1
0
0
0
0
0
33
58
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
67
58
0
0
Test 2
TS31
TS79
TS61
TS52
AT62
AT77
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
1
0
1
0
0
0
50
58
0
0
0
0
1
1
0
0
50
58
0
0
1
1
1
1
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
25
50
0
0
0
0
1
0
0
0
25
50
0
0
0
0
0
0
0
0
0
0
0
0
Script 5 Overall
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
43
53
0
0
71
49
25
50
71
49
0
0
0
0
0
0
14
38
0
0
14
38
0
0
29
49
0
0
37
-------
Test Subjects
Control Subject
Attendants
Figure 3.5-1a. Script 5, Test 1 occurrence (%) of cross-contamination
Test Subjects
Attendants
Figure 3.5-1 b. Script 5, Test 2 occurrence (%) of cross-contamination
3.5.2 Quantitative Analysis
The results of the quantitative analysis (Table 3.5-2) provides the same results for spraying cooking oil as
water mist alone. As a note, the disadvantages of using cooking oil are its cost, it makes the
decontamination area harder to clean, and it does not have disinfecting properties against a biological
agent.
38
-------
Table 3.5-2. Script 5 Estimated Contaminated Surface Area (in2)
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Total
Testl
TS62
TS77
TS31
CS79
AT52
AT61
1
NO
NO
NO
NO
NO
2
4
2
NO
NO
2
1
NO
NO
NO
NO
NO
NO*
NO
NO
9
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
1
6
NO
NO
NO
NO
5
10
2
9
NO
2
Test 2
TS31
TS79
TS61
TS52
AT62
AT77
20
NO
2
NO
NO
NO
NO
NO
36
96
NO
NO
9
35
8
1
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
80
NO
NO
NO
NO
4
NO
NO
NO
NO
NO
NO
NO
NO
NO
29
35
50
177
NO
NO
*NO: contamination not observed
3.6 Script 6: SOG Using Two Attendants with a Scripted One-Step Outer
Garment Water Mist Spray Decontamination Sequence with Test Subjects
Donning an Extra Inner Tyvek® Suit (One Test)
Script 6: This script followed the Script 4 procedure, but test subjects, the control subject, and
attendants wore three coveralls (an inner Tyvek® suit representing the skin, a second protective inner
suit, and a protective outer Tychem® suit). This test was designed to determine if an added layer of
protection would reduce test subject exposure to contamination.
3.6.1 Qualitative Analysis
The qualitative results for this test script are listed in Table 3.6-1 (seven test subjects, one control subject,
and two attendants). A second test was not performed due to the sample size, and the similarity in
procedure to script 7 (changed suit from Tychem® to Tyvek®). Two test subjects, TSOO and TS63,
proceeded through the decon line twice. The probability of occurrence (%) of cross-contamination for
each region of the body is illustrated in Figure 3.6-1. The addition of a protective suit to the already
effective water misting approach considerably reduced the probability of occurrence of cross-
contamination among the test subjects, control subject, and attendants. The examination of the inner suit
(skin) of the attendants and the control subject revealed no cross-contamination.
39
-------
Table 3.6-1. Script 6 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
TSOO
TS63
TS79
TS77
TS52
TSOOB*
TS63B*
CS30
AT61
AT31
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
Head, Neck, and Shoulders
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Front
0
0
1
0
0
0
0
0
0
0
14
38
0
0
Left Arm
0
0
0
0
1
0
0
0
0
0
14
38
0
0
Right Arm
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Back
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Left Leg
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Right Leg
0
0
1
0
0
0
0
0
0
0
14
38
0
0
"Second round -test subject proceeded through decon two times
Test Subjects
Control Subject
Attendants
Figure 3.6-1. Script 6 occurrence (%) of cross-contamination
3.6.2 Quantitative A nalysis
The results of the quantitative analysis (Table 3.6-2) confirmed very low, if any, cross-contamination (less
than 1-inch spots observed on the innermost "skin" suits of some test subjects). No cross-contamination
was observed for either the control subject or the attendants.
40
-------
Table 3.6-2. Script 6 Estimated Contaminated Surface Area (in2)
Test Subject ID
TS30
TS63
TS79
TS77
TS52
TSOOB
TS63B
CS30
AT61
AT31
Head, Neck, and Shoulders
NO*
NO
NO
NO
NO
NO
NO
NO
NO
NO
Front
NO
NO
1
NO
NO
NO
NO
NO
NO
NO
Left Arm
NO
NO
NO
NO
2
NO
NO
NO
NO
NO
Right
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Back
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Left Leg
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Right Leg
NO
NO
2
NO
NO
NO
NO
NO
NO
NO
Total
NO
NO
3
0
2
NO
NO
NO
NO
NO
*NO: contamination not observed
3.7 Script 7: SOG Using Two Attendants with a Scripted One-Step Outer
Garment Water Mist Spray Decontamination Sequence with Test Subjects
Donning Three Tyvek® Suits (Two Tests)
Script 7: This script is similar to the Script 6 procedure, with all test subjects, the control subject, and
attendants again wearing three coveralls, but with the difference that the outermost protective suit was
Tyvek® instead of Tychem®. This test was designed to determine if replacing the expensive, chemical-
resistant outer Tychem® coverall with the less expensive and more breathable Tyvek® would affect the
protectiveness to inner suit contamination.
3.7.1 Qualitative A nalysis
The qualitative results for this test script are listed in Table 3.7-1 for Test 1 (five test subjects and two
attendants) and Test 2 (three test subjects, one control subject, and two attendants). The probability of
occurrence (%) of cross-contamination for each region of the body is illustrated in Figures 3.7-1 a and
3.7-1 b for Tests 1 and 2, respectively. Exchanging the more expensive outer Tychem® coverall for the
less expensive Tyvek® coverall appeared to make no difference in results under the test conditions.
These tests also confirmed the results of Script 6. The use of a secondary (inner) protective suit, in
conjunction with the water mist decontamination approach, resulted in minimal or non-existent cross-
contamination to the innermost suit (skin).
41
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Table 3.7-1. Script 7 Qualitative Analysis Occurrence of Cross-Contamination
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Testl
TS61
TS31
TSOO
TS63
TS30
AT77
AT52
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
50
71
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Test 2
TS61
TS30
TS77
CS52
AT63
ATOO
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Script 7 Overall
Test Subject Average (%)
Test Subject Stdev
Attendant Average (%)
Attendant Stdev
0
0
0
0
0
0
25
50
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
42
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Test Subjects
Attendants
Figure 3.7-1 a. Script 7, Test 1 occurrence (%) of cross-contamination
Test Subjects
Control Subject
Attendants
Figure 3.7-1b. Script 7, Test 2 occurrence (%) of cross-contamination
3.7.2 Quantitative A nalysis
The results of the quantitative analysis (Table 3.7-2) confirm the very low cross-contamination. No cross-
contamination was observed for either the test subjects or the control subject for this test script. Spots of
contamination of less than 1 inch were observed on one of the attendants (front torso). The results of this
script along with the results of Script 7 suggest that the use of a secondary (inner) protective Tyvek® suit
might serve to completely protect the test subjects from cross-contamination.
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Table 3.7-2. Script 7 Estimated Contaminated Surface Area (in2)
Test Subject ID
Head, Neck, and Shoulders
Front
Left Arm
Right Arm
Back
Left Leg
Right Leg
Total
Testl
TS61
TS31
TSOO
TS63
TS30
AT77
AT52
NO*
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
1
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
1
NO
Test 2
TS61
TS30
TS77
CS52
AT63
ATOO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
*NO: contamination not observed
3.8 "Contaminated Sample" Analysis
All "samples" that had been dropped off by the test subjects were put through the standard sample-
handling procedure detailed in Section 2.2.9, which was devised to eliminate any cross-contamination.
This sample-handling procedure led to complete elimination of potential cross-contamination from the
collected samples into areas of the SZ.
44
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4 Quality Assurance
This project was performed under an approved Category III Quality Assurance Project Plan (QAPP) titled
"Decontamination Line Protocol Evaluation for Biological Contamination Incidents (April 2014)."
4.1 Sampling, Monitoring, and Analysis Equipment Calibration
The majority of samples were qualitative rather than quantitative in nature. None of the sampling and
analysis equipment required calibration, with the exception of the scale(s) used to weigh the fluorescent
dye and brushes. All scales were certified by the manufacturer as calibrated or had the calibration verified
annually by EPA's Air Pollution Prevention and Control Division (APPCD) on-site Metrology Laboratory
(RTP, NC). Calibration checks were performed prior to each measurement for proper performance by
comparing the reading to Class S weights. If deficiencies were noted (e.g., reading fell outside of the
accepted ± 1% tolerance), the instrument was adjusted to meet calibration tolerances and recalibrated
within 24 hours. If tolerances were not met after recalibration, additional corrective action was taken,
including recalibration and/or replacement of the scale.
4.2 Data Quality
The purpose of this study was to evaluate the effectiveness of variations of the decontamination and PPE
doffing procedures of the SOG used to provide guidance to EPA and contractors on decontamination of
personnel and samples in long-term response to biological contamination. This long-term decon line
procedure is used to remove PPE without exposing personnel to contamination and to prevent the spread
of contamination beyond the EZ.
The QAPP in place for this project was followed with only a couple of deviations:
• All microbiological evaluation of the SOG was deferred until this optimization task was completed.
• Air purifying respirator full-face masks (Scott Safety AV-3000) were used during the evaluation
instead of the same mask with powered air purifying respirators adaptors. This change was deemed
to have no significant impact on the usability of the test results and was implemented primarily for
simplicity.
4.3 Quality Assurance (QA)/Quality Control (QC) Checks
Uniformity of the test materials was critical for assuring reliable test results. Uniformity was maintained by
obtaining a large enough quantity of PPE from a limited number of reputable suppliers to complete these
tests. All PPE was stored away from the EZ, which has areas that could cause cross-contamination.
Supplies and consumables were examined for evidence of tampering or damage upon receipt and prior to
use, as appropriate. Supplies and consumables showing evidence of tampering or damage were not
used. All examinations were documented, and supplies were appropriately labeled. Project personnel
checked supplies and consumables prior to use to verify that they met specified task quality objectives
and did not exceed expiration dates.
45
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4.4 Acceptance Criteria for Critical Measurements
The data quality objectives assigned to this study were qualitative (fluorescent light being used to detect
visible areas of contamination) rather than quantitative in nature, and no critical measurements were
needed to address the stated objectives. Photographs have been retained for further inspection.
A variety of media (still images and video recordings) and records (e.g., raw data collected during the
testing process, laboratory notebook narratives) were used to document the project. Negative controls
tests, or pre-contamination checks, of the inner suits and gloves were performed under UV light on all test
subjects prior to contamination. Test subjects that were found wearing a suit that fluoresced were rejected
and asked to don new inner suits and gloves. Control subjects served as field blanks (i.e., were not dosed
but went through the entire decon line) for each test script. They were always the final participant to
indicate whether cross-contamination was occurring from anything or anyone in the decon line itself.
Table 4.4-1 lists the QA/QC samples,
Table 4.4
the acceptance criteria, and the corrective actions implemented.
•1. QA/QC Sample Acceptance Criteria
Sample Type
Negative control -
personnel and
items
Field blank -
personnel and
items
Description
A person or item not
dosed and checked for
background
contamination prior to
dosing
A person or item not
dosed and run through
the decon line after
contamination is present
Purpose
Demonstrate that
evidence of cross-
contamination is not
inherent in personnel or
items
Identify sources of cross-
contamination between
test subjects
Acceptance
Criteria
No detectable
contamination
NA
Corrective Actions
Replace inner suit or
other source of
contamination; instruct
test subject to remove
PPE and don new
Refine decon line
procedures
Frequency
Once prior to
each round
One per sample
type per round
4.5 Data Quality Audits
This project was QA Category III and did not require technical systems or performance evaluation audits.
4.6 QA/QC Reporting
QA/QC procedures were performed in accordance with the QAPP for this investigation.
46
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5 Summary and Recommendations
While improvements to the SOG were not quantifiable, steps were identified and defined in the protocols
that proved successful at preventing cross-contamination in most situations. The overall test results of this
study indicated that the liquid in the existing protocol can be a contaminant carrier, so procedures using
large amounts of liquid and scrubbing should be avoided. It must be noted that the test did not take into
account the disinfecting properties of a decontamination solution, such as 1:10 hypochlorite bleach
solution, but rather focused on the transport of contaminants.
Several procedural elements resulted in a large reduction or complete elimination of cross-contamination
among test participants and decon line personnel:
• A secondary protective Tyvek® suit under the main Tyvek® or Tychem® suit
• A light mist or spray
• Careful doffing with the help of an attendant who changes gloves between each test subject
Even with a greatly improved process for reducing contamination, a small probability still exists for
potential contamination. To that end, showering after leaving the decon line is recommended.
The following summarizes the main results of this study:
• The use of a three-step decontamination approach (spray-brush-rinse) of the test subjects can
potentially increase the chances of liquid infiltration through the vulnerabilities of the protective
ensemble of suit, gloves, respirator, and tape, resulting in contamination of the skin. Further, the
reuse of the brush on multiple test subjects during the decon process can increase the likelihood of
cross-contamination.
• The addition of a second attendant in the doffing tent (boot removal) does not appear to have a
positive impact on reducing or eliminating cross-contamination among the attendants and the test
subjects. To the contrary, the results suggest an increase in the number of personnel that will be
cross-contaminated.
• A gentle water mist is likely to prove more efficient in reducing contamination of workers than the
more complex three-step (spray-brush-rinse) decontamination approach. Although the use of a gentle
spray of cooking oil seems to be as effective as the light water spray, it has disadvantages such as
cost and increased difficulty of cleanup.
• The use of multiple gloves by the attendants in the doffing section can help reduce or eliminate cross-
contamination. The attendants should be instructed to doff outer gloves whenever helping with parts
of the PPE with suspected vulnerabilities. For instance, the outer tape and gloves of the test subjects
can be assumed to be contaminated. After touching these items, gloves should be doffed before
touching the outside of the suit during doffing.
• The use of a secondary inner Tyvek® suit by responders can drastically decrease or eliminate cross-
contamination.
47
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• Special consideration should be given to procedures for handling the sample collection bags to avoid
any cross-contamination from collected "samples" into any SZ areas. The multi-step decontamination
procedure involving two sample handlers that was used in this testing can be very effective in
avoiding transfer of contamination during sample handling.
• Even with modified procedures, the best test result demonstrated minor contamination of one test
subject. Therefore, complete showering of the skin after doffing PPE can further ensure that no
contaminants are spread.
• Future evaluations are recommended to assess any changes to the biological decon line that have
not been tested.
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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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