©EPA
www.epa.gov/nhsrc
technical BR
Evaluation of Liquid and Foam Decontamination
Technologies for Surfaces Contaminated by
Bacillus anthracis Spores
EPA investigates the effectiveness of liquid and foam decontamination
technologies for surfaces contaminated with biological agents
Background
As part of U. S. EPA's Office of Research and Development,
the National Homeland Security Research Center (NHSRC)
provides products and expertise to improve our nation's
ability to respond to environmental contamination caused by
terrorist attacks on our nation's water infrastructure,
buildings and outdoor areas.
NHSRC conducts research related to:
• Detecting and containing contamination from
chemical, biological, and radiological agents
• Assessing and mitigating exposure to
contamination
• Understanding the health effects of contamination
• Developing risk-based exposure advisories
• Decontaminating and disposing of contaminated
materials.
Because of their potential use as weapons of mass
destruction, biological agents are a significant
terrorist threat. Once released, agents such as
bacteria and viruses can cause disease or death in
humans, animals, and plants by spreading through
air, water distribution systems, and the food
supply.
Bacillus anthracis—the spore-forming bacterium
which causes anthrax—is one of the most likely
biological agents to be used by terrorists. In the
United States, twenty-three people became
infected with anthrax and five died after envelopes
containing B. anthracis spores were mailed to
governmental and news media offices during the
months following the Sept. 11 terrorist attacks.
Sites where letters were received and many U.S.
postal service facilities became contaminated with spores.
Although person to person transmission has not been demonstrated, humans can acquire
anthrax by contact with spores. Anthrax is a naturally occurring disease most commonly found
in grazing animals such sheep, cattle, and goats. Spores can be found in the tissues from
infected animals or in contaminated products made from bone, hide, wool, or hair.
Spores pose a continuing threat because they are viable for decades, even under extreme
environmental conditions. B. anthracis spores can be processed or weaponized and delivered
through the air over wide areas. A major attack using B. anthracis spores could cause many
deaths and interrupt vital civilian and government operations.
One of the key challenges following an anthrax attack is cleaning up contaminated areas for re-
entry and re-use. The primary goal is to reduce the cost and time it takes to remediate an area
while protecting workers and nearby residents.
The challenge: find decontaminant technologies that are effective against spores
B. anthracis forms spores that are highly resistant to severe environmental conditions, including
exposure to harsh chemicals. In 2001, when remediation of facilities contaminated by B. anthracis
spores began, there were no EPA-registered products specifically for use against the spores. EPA's
Office of Pesticide Programs had to issue crisis exemptions for the sporicidal products needed for
remediation.
April 2011
This document does not constitute nor should be construed as an EPA endorsement of any particular
product, service, or technology.
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The Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel1 was
convened in 2007 to provide guidance on test methods for determining on the efficacy of
antimicrobial products for inactivating B. anthracis spores. The Panel proposed that, in order to
be registered as a sporicidal decontaminant against B. anthracis spores, a decontaminant
technology had to achieve a mean (average) 6 Iog10 reduction in the number of viable spores.
EPA's decontamination technology evaluation research
EPA conducted tests to collect performance (efficacy) data on a variety of products and
technologies that might be able to decontaminate surfaces contaminated with B. anthracis
spores [1, 2, 3]. Decontamination technologies were investigated under conditions similar to
those likely to occur in buildings or outdoor populated areas. Although one of the major factors
influencing the decontaminant effectiveness is the type of material being decontaminated, a
number of other issues are important, as shown in Table 1.
Table 1 Factors That Influence Decontaminant Effectiveness
• Relative humidity
• Temperature
• Characteristics and amount of the biological agent
•
•
Type of material or porosity of a surface being
How long the decontaminant is in contact with
on the
surface
decontaminated
the
surface
or material
• Concentration of the decontaminant
Table 2 lists general descriptions of the twelve decontaminants tested.
Table 2 Liquid and Foam Decontaminant Technologies Tested
Decontamination Technology
Calcium polysulfide
CASCAD™ Surface Decontamination
Foam (SDF)
Decon Green
DioxiGuard™
EasyDECON®200
Klozur™
MINNCARE®ColdSterilant
Oxonia Active®
Peridox® RTU
SanDes
Spor-Klenz® RTU
Ultra Clorox® Germicidal Bleach a
Description/Active
Ingredients
Calcium polysulfide
Hypochlorite, hypochlorous acid
Hydrogen peroxide
Chlorine dioxide
Hydrogen peroxide
Sodium persulfate, hydrogen
peroxide
Hydrogen peroxide, peracetic acid
Hydrogen peroxide, peracetic acid
Hydrogen peroxide, peracetic acid
Chlorine dioxide
Hydrogen peroxide, peracetic acid
Sodium hypochlorite,
hypochlorous acid
Vendor/Source
VGS, Inc.
Allen-Vanguard Corp.
Developed by the U.S. Army
Frontier Pharmaceutical Inc.
EFT Holdings Inc.
FMC Corp.
Minntech Corp.
Ecolab Inc.
GET LLC
DTI-Sweden AB
STERIS Corp.
The Clorox Co.
Abbreviations Used
in Tables 4,5,6
Cal poly
CASCAD
Decon Green
DioxiGuard
EasyDECON
Klozur
MINN
Oxonia
Peridox
SanDes
Spor-Klenz
pH Bleach
a Bleach was amended by diluting with water and using acetic acid to lower the pH to between 6 and 7
Tests were conducted using the decontaminants on one or more of eighteen materials. Glass
and topsoil were test materials in two studies. In each technology evaluation, B. anthracis
1 Final Meeting Minutes for July 17-18, 2007 Scientific Advisory Panel: Guidance on Test Methods for Demonstrating the
Efficacy of Antimicrobial Products for Inactivating Bacillus anthracis Spores on Environmental Surfaces
April 2011
EPA/600/S-11/003
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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spores were spiked on coupons made from representative porous or non-porous materials used
in buildings or outdoors.
As seen in Table 3, eight decontaminant technologies achieved higher than mean 6 Iog10
reductions of viable B. anthracis spores on at least five materials. Seven achieved complete
spore inactivation on five or more materials.
CASCAD™ SDF, Decon Green, EasyDECON® 200, MINNCARE® Cold Sterilant, Oxonia Active®,
and Peridox® RTU inactivated spores on 70% or more of materials tested.
Table 3 Decontaminants Tested, Number of Materials Showing Mean 6 Log10 Spore
Reductions or Higher, and Contact Times
Decontaminant
Technology
Calcium polysulfide
CASCAD™ SDF
Decon Green
DioxiGuard™
EasyDECON® 200
Klozur™
MINNCARE® Cold
Sterilant
Oxonia Active®
Peridox® RTU
SanDes
Spor-Klenz® RTU
Ultra Clorox®
Germicidal Bleach a
Number of
Materials
Tested
4
17
10
7
10
1
7
8
10
7
10
14
Number of Materials on
Which a Higher Than
Mean 6 Logic
Reductions in Spores
Was Observed
0
14
7
0
8
0
6
6
8
0
8
9
Number of Materials
on Which Spores
Were Inactivated
Completely
0
12
7
0
8
0
6
5
7
0
4
7
Contact Times of
Decontaminants on
Materials
60min
30 min
120min (topsoil)
60min
10min
30 min (non-porous)
60 min (porous)
48 hours (topsoil)
10 min (non-porous)
30 min (porous)
60 min
30 min (non-porous)
60 min (porous)
70 min
30 min (non-porous)
60 min (porous)
60 min
a Bleach was amended by diluting with water and using acetic acid to lower the pH to between 6 and 7
Only two of the twelve decontaminants caused any visible damage to the materials being
decontaminated. Calcium polysulfide left grayish residue on glass and topsoil coupons. The
residue was not removed from the glass during any spore extraction processing for quantitative
or qualitative analysis. Because of material surface characteristics, it could not be determined
whether the residue was also left on the bare pine wood or unpainted concrete. CASCAD™
SDF on painted cinder block coupons caused the top coat of paint to peel away from the primer
coat.
Tables 4 and 5 present the results of the decontaminant technology evaluations. Generally,
more of the decontaminants achieved higher mean Iog10 reductions in the number of viable
spores on non-porous materials than on porous materials. However, some decontaminants
achieved greater than mean 6 Iog10 reductions on both types of materials.
April 2011
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Table 4 Summary Results on the Efficacy of Liquid and Foam Decontaminants on Non-
porous Materials Contaminated With Bacillus anthracis Spores
Materials Tested
Aluminum [1]
Decorative
Laminate [2]
Galvanized Metal
Ductwork [2]
Glass [1,2]
Glazed Porcelain [1]
Sealed Granite [1]
Stainless Steel [1]
Ranges of Mean Logic Reductions
> 6
Ha CASCAD b
H Decon Green
H EasyDECON
H Peridox
H pH Bleach c
Spor-Klenz
CASCAD
H MINN
H Oxonia
H CASCAD
\/ |\1|MM
yv. MINN
H Oxonia
H CASCAD [1,2]
H Decon Green [1]
H EasyDECON [1]
H MINN [2]
H Oxonia [2]
H Peridox [1]
H pH Bleach [1,2]
Spor-Klenz [1]
H CASCAD
H Decon Green
H EasyDECON
H Peridox
H pH Bleach
H Spor-Klenz
H CASCAD
H Decon Green
H EasyDECON
H Peridox
H pH Bleach
H Spor-Klenz
H CASCAD
H Decon Green
H EasyDECON
H Peridox
H pH Bleach
Spor-Klenz
5 to 6
4 to 5
SanDes [2]
3 to 4
2 to 3
DioxiGuard
DioxiGuard [2]
1to2
Oto1
SanDes
DioxiGuard
SanDes
Calpoly[2]
a 8< No colony forming units were found in the extracts from the materials following decontamination
b See Table 3 for contact times
c Bleach was amended by diluting with water and using acetic acid to lower the pH to between 6 and 7
April 2011
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
-------
Table 5 Summary Results on the Efficacy of Liquid and Foam Decontaminants on
Porous Materials Contaminated with Bacillus anthracis Spores
Materials Tested
Asphalt Paving
Aggregate (Fine) [1]
Bare Pine Wood [2]
Butyl Rubber
Sealant Tape [1]
Concrete [1]
Industrial Grade
Carpet [2]
Painted
Cinder Block [2]
Painted Wallboard
Paper [2]
Paving Brick [1]
Topsoil [2,3]
Treated Wood [1]
Unpainted
Concrete [2]
Ranges of Mean Logic Reductions
> 6
*a CASCAD b
Peridox
H CASCAD
H Decon Green
H EasyDECON
H Peridox
H pH Bleach
H Spor-Klenz
H CASCAD
H EasyDECON
pH Bleach
CASCAD
H MINN
Oxonia
H CASCAD
H MINN
H Oxonia
pH Bleach
H MINN
H Oxonia
H CASCAD
H Decon Green
H EasyDECON
H pH Bleach
H Spor-Klenz
X CASCAD
•& Peridox
Spor-Klenz
5 to 6
MINN
4 to 5
Oxonia
Decon
Green
CASCAD
pH Bleach
3 to 4
pH Bleach c
Peridox
Klozurd[3]
2 to 3
Decon Green
Spor-Klenz
CASCAD
1to2
EasyDECON
Peridox
Spor-Klenz
DioxiGuard
DioxiGuard
CASCAD e [3]
Oxonia [3]
pH Bleach [2]
Decon Green
pH Bleach
Oto1
Cal poly
DioxiGuard
pH Bleach
SanDes
SanDes
SanDes
DioxiGuard
SanDes
Cal poly [2]
pH Bleach [3]
EasyDECON
Cal poly
a 8< No colony forming units were found in the extracts from the materials following decontamination
b See Table 3 for contact times
c Bleach was amended by diluting with water and using acetic acid to lower the pH to between 6 and 7
d Contact time was 48 hours; the Klozur™ technology, which uses hydrogen peroxide and persulfate chemistry, was tested at relatively longer
contact times based upon its typical field-use conditions and achieved a 3.50 logic reduction after 48 hours of contact
e Contact times for CASCAD, Oxonia, and pH Bleach [3] were 120 min
April 2011
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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B. subtilis was included in one of the investigations [2] to provide data for a non-pathogenic
organism that might suffice for use in testing as a surrogate for B. anthracis.
Table 6 shows that test results obtained with spores from B. subtilis are similar, but not identical
to, results obtained with B. anthracis spores. These results underscore that, although
experimental results using surrogates might be indicative of the behavior of biological agents,
they are not necessarily predictive.
Table 6 Summary Results on the Efficacy of Liquid and Foam Decontaminants on Porous
and Non-porous Materials Contaminated with Bacillus subtilis Spores
Materials Tested
Bare Pine Wood [2]
Decorative
Laminate [2]
Galvanized Metal
Ductwork [2]
Glass [2]
Industrial Grade
Carpet [2]
Painted
Cinder Block [2]
Painted Wallboard
Paper [2]
Topsoil [2]
Unpainted
Concrete [2]
Ranges of Mean Logic Reductions
> 6
MINN3
Hc CASCAD
H MINN
H Oxonia
H CASCAD
H MINN
H Oxonia
H CASCAD
H MINN
H Oxonia
H CASCAD
H MINN
H Oxonia
H CASCAD
H MINN
H Oxonia
H pH Bleach
H CASCAD
H MINN
H Oxonia
5 to 6
Oxonia
4 to 5
3 to 4
2 to 3
1to2
CASCAD
SanDes
Oto1
Cal poly
DioxiGuard
pH Bleach b
SanDes
DioxiGuard
SanDes
Cal poly
DioxiGuard
San Des
DioxiGuard
SanDes
DioxiGuard
SanDes
DioxiGuard
SanDes
Cal poly
pH Bleach
Cal poly
DioxiGuard
3 See Table 3 for contact times
b Bleach was amended by diluting with water and using acetic acid to lower the pH to between 6 and 7
c ^ No colony forming units were found in the extracts from the materials following decontamination
April 2011
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Technology Evaluation Reports Referenced
[1] Calfee, M.W. 2010. Biological Agent Decontamination Technology Testing. Technology
Evaluation Report. Washington, D.C.: U.S. Environmental Protection Agency. EPA/600/R-
10/087.
[2] Wood, J. 2009. Evaluation of Liquid and Foam Technologies for the Decontamination ofB.
anthracis and B. subtilis on Building and Outdoor Mater/a/s.Technology Evaluation Report.
Washington, D.C.: U.S. Environmental Protection Agency. EPA/600/R-09/150.
[3] U.S. Environmental Protection Agency. 2010. Evaluation of Liquid and Foam Technologies
for the Inactivation of Bacillus anthracis Spores in Topsoil. Investigation Report. Washington,
D.C.: U.S. Environmental Protection Agency. EPA/600/R-10/080.
Contact Information
For more information, visit the NHSRC Web site at www.epa.gov/nhsrc.
Technical Contacts: Joseph Wood (wood.joe@epa.gov
Worth Calfee (calfee.worth@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)
April 2011
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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