Decontamination Options for Sensitive Equipment in Critical
Infrastructure following a Bacillus anthracis Incident
Purpose
This technical brief provides decision makers with practical information on decontamination methods
that could be used to restore critical infrastructure during a response to a release of Bacillus anthracis,
the causative agent of anthrax. This brief reviews fumigation technologies that have been shown to
decontaminate sensitive equipment contaminated with B. anthracis or surrogate spores and provides
an overview of the on- and off-site decontamination processes.
Introduction
Critical infrastructure represents a wide range of possible functions, institutions or businesses. After a
wide-area release of B. anthracis, the functionality of affected power plants, water and sewer services,
law enforcement, fire protection, and hospitals and other health care institutions must be restored.
Restoring the functionality of infrastructure requires technologies capable of decontaminating
sensitive equipment such as mechanical, electronic, or other powered devices that are necessary for
facility operations.
Although several decontamination technologies are capable of effectively inactivating B. anthracis
spores, every technology has limitations, safety issues, and material-compatibility constraints. Some
decontamination technologies may cause corrosion or other collateral damage to sensitive equipment
necessary for the functionality of critical infrastructure. Therefore, a Remedial Action Plan should
include decontamination procedures for the entire facility, as well as the special handling and non-
destructive decontamination methods required to prevent damage to the sensitive equipment located
within the facility.
EPA has identified the effectiveness as a function of operational parameters for several volumetric
decontamination methods that may be considered to decontaminate areas contaminated by B.
anthracis spores. These methods include fumigation techniques using methyl bromide (MeBr), chlorine
dioxide (CIO;), formaldehyde, hydrogen peroxide (H202), ethylene oxide (EtO), methyl iodide, and
ozone; and fogging with sporicidal liquids [1]. Additionally, some of these methods have been
evaluated by EPA specifically for use with sensitive equipment. This brief delivers an overview of such
methods.
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Office of Research and Development
December 2017
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Decontamination Methods for Electronic Equipment
The compatibility of sensitive equipment and decontamination agents should be understood when
deciding on a cleanup approach for a B. anthracis incident. EPA has completed a number of material
compatibility fumigation studies on electronic equipment (desktop computers, monitors, fax machines,
cell phones, CDs) using CI02, H2O2, MeBr (with 2% chloropicrin), and EtO. The materials and electronic
systems used in these studies were chosen to be characteristic of equipment, components, and
materials found in critical infrastructure or high-value items. For example, computer systems were
employed that included sub-components often found in high-end medical, communication, and
security equipment. A summary of details on the test parameters and material compatibility from the
EPA studies can be found in the Assessment of the Impact of Decontamination Fumigants on Electronic
Equipment technical brief [2]. Table 1 summarizes some of the findings on the fumigants tested and
their impacts on electronic equipment.
Table 1. Summary of the Decontamination Agents Tested on Electronic Equipment (Desktop
Computers, Monitors, Fax Machines, Cell Phones, CDs) *
Fumigant
Findings from Fumigant Testing
Ethylene Oxide [3]
Little or no impact on materials tested; generally, the most material-compatible
method for decontamination of high-value and/or irreplaceable objects; treatment is
typically performed in a small, controlled chamber and must be performed precisely.
EtO is not suitable for whole-building fumigation and equipment should be removed
to another location (exsitu) within the site or off-site in a controlled environment.
Methyl
Bromide
(with 2%
Chloropicrin)
[4]
Power supplies in all MB-fumigated computers failed, some catastrophically, due to
the chloropicrin; some corrosion of low carbon steel and steel outlet/switch boxes
was observed; other materials with potential for damage include metal bearings and
CD/DVD drives. Chloropicrin has been shown to cause oxidation or adverse effect on
the electronics [5], (Without the use of chloropicrin, MeBr may be suitable for
whole-building/room decontamination of porous sensitive items. EPA is currently
conducting a study on the impacts of MeBr without chloropicrin on electronic
equipment.)
Hydrogen
Peroxide [6]
Fumigation did not appear to affect the electronic components tested; computer
performance did not appear to be significantly affected up to one year following
fumigation. With proper control of humidity and exposure time, H202 is suitable for
whole-building/room decontamination with sensitive items.
Chlorine Dioxide
[4, 6-8]
At 3000 ppm, fumigation caused some corrosion around the edges of desktop
computers. It left powdery residue and damaged some CD/DVD drives. With the
exception of some DVD drives, the computers were still in operation with no
replacement parts one year after fumigation. A separate study [8] showed less
detrimental impact on computer functionality when fumigating with lower levels of
CI02.
* It is important to note that the results are for the specific conditions to which the material or equipment was exposed
during testing. Less impact is expected when fumigating at lower concentration or RH.
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Fumigation with EtO is generally the most material-compatible method for fumigation of high-value
and/or irreplaceable objects. EtO was used successfully to treat items (at an off-site facility) retrieved
from the Hart Senate Office Building during the 2001 anthrax incident [9]. Overall, the findings from
EPA studies show EtO fumigation [3] to have the least impact electronic equipment. However, because
EtO is both highly toxic and flammable, it must be used in an extremely well-ventilated area. EtO is not
suitable for wide-area fumigation, such as in a building or in any environment where an ignition source
might be present or possible. Therefore, it is recommended that EtO fumigation occur with the object
removed to another location (ex situ) within the site or off-site in a controlled environment. Off-gasing
of EtO from treated materials should also be considered.
Hydrogen peroxide fumigation can be considered a valid option for whole-building/room
decontamination with sensitive items, but process humidity and exposure time must be very carefully
planned and controlled to minimize damage to sensitive items.
Methyl bromide can also be considered for whole-building/room fumigations. Due to its toxicity to
humans, MeBr is frequently mixed with 2 percent chloropicrin (tear gas) to warn users of exposure.
However, chloropicrin should not be added to fumigations for sensitive equipment because
chloropicrin has been shown to cause oxidation or adverse effect on the electronics [5]. EPA is
currently conducting a study on the impacts of MeBr without chloropicrin on electronic equipment.
For whole-building/room fumigations, CI02 is more effective on a broader range of materials than H202
[10], However, computers fumigated with CI02 were more prone to physical/functional deterioration
than those fumigated with H202 [2]. Additionally, results show that relative humidity during fumigation
should be maintained between 65 percent and 75 percent to maximize compatibility for most
materials [7] and that there will be less detrimental impact on computer functionality when fumigating
with lower levels of CI02 [8].
On- And Off-Site Decontamination Techniques for Sensitive Equipment
Sensitive equipment should be identified prior to remediation of the critical infrastructure. It may be
necessary to encapsulate or remove sensitive equipment prior to conducting the facility
decontamination, then determine non-destructive decontamination methods. On-site
decontamination can be performed for non-removable equipment in its original place (in situ) or
equipment can be removed for decontamination to another location (exsitu) within the site or off-site.
In situ and ex situ techniques are described below and Table 2 reviews the pros and cons of each of
these decontamination techniques.
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Table 2. Pros and Cons of On- and Off-Site Decontamination Techniques for Sensitive Equipment
Decontamination Technique	Pros/Cons
In Situ
Protect material/equipment before
whole-building/room
decontamination and decontaminate
material/equipment with a
compatible method.
Can allow for readily available and affordable decontamination
options for decontamination of the whole-building/room and
overall effectiveness of decontamination throughout the facility.
Decontaminating equipment separately will require more
preparation time for the enclosing/encapsulation requirements
and decontamination processes.
Leave material/equipment
unprotected for whole-building/room
decontamination inclusion.
Less time required for preparation and decontamination
processes. Will limit decontamination options to methods that
are compatible only with sensitive equipment and could reduce
the overall effectiveness of decontamination throughout the
facility.
Ex Situ
Remove the material/equipment for
on-site or off-site decontamination.
Can allow for readily available and affordable decontamination
options for decontamination of the whole-building/room and
overall effectiveness of decontamination throughout the facility.
The dismantling, enclosing/encapsulation, and transport
requirements for removed material/equipment will likely be time
consuming and costly.
In Situ Decontamination
In situ decontamination of non-removable equipment will involve either covering the equipment to
protect it from the whole-building/room decontamination process and later decontaminating the
equipment with a compatible method or leaving equipment unprotected for inclusion of a whole-
building/room decontamination process that is compatible with sensitive equipment. The
decontaminant to be used on the sensitive material/equipment should be selected based on material
compatibility decontamination studies and usage in previous incidents. The general procedures for
preparing the equipment for a compatible decontamination method and protecting equipment prior to
whole-building/room decontamination are listed below. Modifications can be made on-site as deemed
necessary.
• Enclose/cover the material/equipment, using one of these or other possible techniques:
o If fogging or fumigating, bag the item or cover it with heavy duty plastic and seal it shut,
leaving enough air space in the enclosure for introduction of decontaminant.
o Enclose the item in a small portable tent that is sealed or boxed and sealed, leaving
enough enclosed space to perform the selected decontamination process. The tenting
materials need to be compatible with both facility and sensitive equipment
decontaminants.
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•	Follow the preparation procedures for the specific decontamination method selected. The
placement of fans to distribute or dry the decontaminant or other modifications to the
enclosed space, such as adding ports for air and/or gas exchange, may be needed prior to
conducting decontamination.
Ex Situ Decontamination
In many instances, sensitive equipment may need to be removed because it cannot be
decontaminated in place. For ex situ decontamination, the sensitive item may be moved to a Conex
box or other enclosure for decontamination at the site or off-site. The decontaminant should be
selected based on material compatibility decontamination studies and usage in previous incidents.
Once inside the enclosure, items can be decontaminated in accordance with procedures for the
selected decontamination method.
Prior to removing the sensitive items, a label/tag system should be established to track items. Several
labeling options are available, such as using evidence tags or labeling bags with a predetermined
nomenclature system. Bar coding or other electronic tracking may be the most efficient method given
the large quantity of items to be handled.
Below is a list of guidelines for removing sensitive items. Detailed procedures are not presented here,
as these will be determined during a response by decision-makers.
•	Bag the item. First, double bag sensitive items using heavy-duty plastic bags most resistant to
punctures. Large and/or heavy items, can be double wrapped in heavy duty plastic sheeting,
such as Visqueen™ (British Polythene Ltd., London, UK).
•	Tape the bags shut with duct or other tape with similar or better adhesive properties. Large
items wrapped in plastic sheeting should be taped to secure all edges of the plastic to the item.
•	Label or tag the bag using a labeling system devised for sensitive items to be moved. Label the
bag or the wrapped item using permanent markers and labels, and ensure that markings are
dry so that they are not smudged during transport.
•	Document items on a chain-of-custody form and any other form/logbook as decided upon
during the response.
•	Decontaminate the container/bag outer surface prior to placing the container in a shipping
area/container.
•	Transport the bags to a secure location for ex situ decontamination. It may be necessary to
further place the bags into another container for transport, such as a drum, Gaylord box, or roll-
off box.
•	Track the location and disposition of the sensitive item electronically (database or spreadsheet)
in accordance with an approved data management plan.
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Conclusion
Sensitive equipment should be identified prior to remediation of the critical infrastructure. A whole-
building/room decontamination approach that is compatible with sensitive equipment may be
selected, but it could limit decontamination efficacy throughout the facility. If sensitive equipment
cannot be included in the whole-building/room decontamination approach, it will be necessary to
encapsulate or remove the items prior to decontamination of the facility, then determine non-
destructive decontamination methods for the items. Material compatibility needs to be carefully
understood when considering the cleanup of the sensitive equipment associated with the functionality
of critical infrastructures. Overall, the findings from EPA studies show EtO fumigation [2, 3] to have the
least impact electronic equipment. However, it is recommended that EtO fumigation occur with the
object removed to another location (ex situ) within the site or off-site in a controlled environment,
which will limit its use in a wide-area incident. Hydrogen peroxide and MeBr (without chloropicrin)
could be considered valid options for whole-building/room fumigations with sensitive items. A study is
currently underway to look at the impacts of MeBr without chloropicrin on electronic equipment. In
general, physical and functional deterioration of sensitive equipment is more likely with CI02 vs. H202
fumigations [2]. However, for whole-building/room fumigations, CI02 is more effective on a broader
range of materials than H202 [10] and fumigating with lower levels of CI02 will allow for less
detrimental impact on computer functionality [8]. For both fumigants, process humidity and exposure
time must be very carefully planned and controlled to minimize damage to sensitive items.
Disclaimer
The U.S. Environmental Protection Agency through its Office of Research and Development funded and
managed the research described herein under several contractual agreements listed in the references.
Compilation of this technical information was conducted by Booz Allen Hamilton under EP-G13C-
00404. This summary has been subjected to the Agency's review and has been approved for
publication. Note that approval does not signify that the contents reflect the views of the Agency.
Mention of trade names, products, or services does not convey official EPA approval, endorsement, or
recommendation.
References
1.	U.S. EPA. Surface Decontamination Methodologies for a Wide-Area Bacillus anthracis Incident.
Washington, DC: U.S. Environmental Protection Agency. EPA/600/S-15/172, 2015.
2.	U.S. EPA. Assessment of the Impact of Decontamination Fumigants on Electronic Equipment.
Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-14/316, 2014.
3.	U.S. EPA. Compatibility of Material and Electronic Equipment with Ethylene Oxide Fumigation.
Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-14/399, 2014.
4.	U.S. EPA. Compatibility of Material and Electronic Equipment with Methyl Bromide and Chlorine
Dioxide Fumigation. Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-12/664,
2012. (http://cfpub.epa.gov/si/si public record report.cfm?dirEntryld=246831)
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5.	LGS Innovations LLC, Alcatel-Lucent. "Assessment and Evaluation of the Impact of Fumigation with
Methyl Bromide Fumigation on Electronic Equipment. Final Report," Murray Hill, NJ: Alcatel-Lucent
USA Inc.; December 28, 2010.
6.	U.S. EPA. Compatibility of Material and Electronic Equipment with Hydrogen Peroxide and Chlorine
Dioxide Fumigation. Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-10/169,
2010. (http://cfpub.epa.gov/si/si public record report.cfm?dirEntryld=231565)
7.	U.S. EPA. Compatibility of Material and Electronic Equipment with Chlorine Dioxide Fumigation.
Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-10/037, 2010.
(http://cfpub.epa.gov/si/si public record report.cfm?dirEntryld=219487)
8.	U.S. EPA. Decontamination of a Mock Office Using Chlorine Dioxide Gas. Washington, DC: U.S.
Environmental Protection Agency. EPA/600/R-14/208, 2014.
9.	U.S. EPA. Federal On-Scene Coordinator Report for the Capital Hill Site, Washington, DC.
Philadelphia, Pennsylvania: U.S. Environmental Protection Agency Region 3, 2002.
(https://response.epa.gov/sites/DCN0003057Q3/files/osc%20report.pdf)
10.	U.S. EPA. Bio-response Operational Testing and Evaluation (BOTE) Project, Phase 1:
Decontamination Assessment. Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-
13/168, 2013.
Contact Information
For more information, visit the EPA Web site at http://www2.epa.gov/homeland-security-research.
Technical Contact: Shawn Ryan (ryan.shawn@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)
U.S. Environmental Protection Agency
Office of Research and Development

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