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Biofilm Claims for
Antimicrobial Products
A Regulatory Perspective
STEPHEN TOMASINO, PH.D.
SENIOR SCIENTIST
ENVIRONMENTAL PROTECTION AGENCY
ENVIRONMENTAL SCIENCE CENTER
MICROBIOLOGY LABORATORY BRANCH
FORT MEADE, MD
1 2015 OSAP Annual Symposium
Federal Compliance Agency Briefing - EPA
May 29, 2015
Disclaimer 2
This information is distributed solely for the
purpose of pre-dissemination peer review
under applicable information quality
guidelines. It has not been formally
disseminated by EPA. It does not represent
and should not be construed to represent any
Agency Determination or Policy.
Topics for Discussion
EPA’s Microbiology Laboratory
Branch (MLB)
Antimicrobial Product Registration
Method Development and
Assessment
Biofilm Methods/Potential Claims
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EPA’s Microbiology Laboratory
Branch (MLB)
Located at the Environmental Science Center, Fort Meade, MD
GLP Compliant and ISO 17025 Accredited
Areas of Technical Support and Scientific Emphasis:
Efficacy testing of EPA-registered antimicrobial products
Method development and standardization
Lead collaborative studies – for method performance, surrogate verification
Stakeholder outreach – training through laboratory workshops
Participation with standard-setting organizations (ASTM, AOAC)
Interagency research and collaboration (e.g., DHS, DOD)
Bioterrorism/homeland security support – select agent lab for B. anthracis
International harmonization of methods
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MLB’s Current Areas of Emphasis 5
Clostridium difficile – spore production and
storage; efficacy test methods
Biofilm methodologies; growth and efficacy
test methods
Virus claims; efficacy test methods
Porous environmental surfaces – for high
consequence animal pathogens
Antimicrobial wipes
Disinfection hierarchy – demonstration studies
Antimicrobial Product Registration
Under Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA), EPA is responsible for
the registration of pesticidal products
Antimicrobial pesticides are substances used to
destroy or suppress the growth of harmful
microorganisms (including biofilm) on inanimate
environmental surfaces.
Label claims for control of microorganisms on
inanimate environmental surfaces which are
infectious to man are considered directly
related to human health – these are known as
public health antimicrobials.
Under FIFRA, the registrant of an antimicrobial
product with a public health claim is required to
submit efficacy data in support of the product's
registration; efficacy data are generated in the
lab using “standard methods”.
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Testing Methodology Label Claim
EPA’s Goal: Protect Human Health
and the Environment Pesticidal efficacy data are required to
be of sufficient quality to support regulatory decisions. Good Laboratory Practices must be employed.
Each regulatory “model” (e.g., hospital disinfectants, non-food sanitizers, etc.) requires use of a recommended test method, organisms, number of product lots tested, lower certified limits, etc., to produce regulatory-quality data.
Label claims are the basis for efficacy methodology.
Antimicrobial Product Registration 7
Antimicrobial Product Registration
The EPA reviews the product efficacy data
and if the requirements for registration are
met, the product is granted a registration
and is issued an EPA registration number.
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Method Development and Assessment
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Conceptualization
Initial consensus building
Draft the SOP and conduct in-house
demonstration studies
Design ways to assess method performance
and analyst proficiency
Pre-collaborative studies
Collaborative study for method performance
and validation
Data analysis and publication of results
SOP refinement, testing criteria and
peer review
Comment period &
posting of EPA guidance
Standard Test Method and Guidance for
Product Registration
Method Development and Assessment
for Biofilms
Biofilms express unique characteristics, and
therefore require unique and relevant test methods
for measuring product efficacy.
Product label claims must be supported by a
specific method.
Standard methods to treat biofilms have lagged
behind methods to grow biofilms.
Standard methods are in place to grow and treat
biofilms, but require verification.
Official efficacy test guidelines have not been
established to inform registrants which test
methodology and microorganisms are appropriate
to support biofilm claims.
EPA is currently leading collaborative efforts to
generate the data necessary to support a
regulatory strategy to allow biofilm claims on
disinfectant product labels.
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Standard Methods for Biofilm
ASTM Method E2871-13: Evaluating Disinfectant Efficacy
against Pseudomonas aeruginosa Biofilm using the Single Tube
Method
ASTM method E2562-12: CDC biofilm reactor procedure
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Remove and
disaggregate the
biofilm Dilute and
Enumerate
Carrier with biofilm
Standard Methods for Biofilm Single Tube Method (ASTM E2871-13)
•4 mL product + 36 mL neutralizer
•Variable contact times & concentrations
Removal:
1. Vortex
2. Sonicate
3. Vortex 4. Sonicate
5. Vortex
Key Aspects/Steps:
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Expose biofilm to product
and neutralize
Strategy Under Consideration
Use ASTM E2871-13 (Single Tube Method)
A claim for treating biofilms may be added to a registered antimicrobial product.
Pseudomonas aeruginosa – the default test microbe
Borosilicate glass coupons
Evaluate three batches of product.
Evaluate a minimum of five carriers against the disinfectant and 3 carriers as controls.
Conduct neutralization testing in advance of efficacy testing to determine the appropriate neutralizer for the product.
The performance standard (log reduction) is under consideration.
Considering more than one performance standard based on the use site and level of biofilm.
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Potential Label Claims
Kills 99.999% of bacteria in biofilms on a hard, non-
porous surface
Kills a minimum of 99.999% of bacteria in biofilms
Reduces at least 99.999% of bacteria growing in
biofilms
Other related claims:
Kills biofilm bacteria
Controls slime-forming bacteria
Specifically designed and formulated to destroy bacteria
in biofilms
Penetrates biofilms, killing the bacteria living there
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Next Steps
Continue to assess the performance of the Single Tube Method and devise an action plan
Propose appropriate revisions to the ASTM methods
Develop a performance standard – possibly more than one level per potential use-site
Incorporate our knowledge of the test methods and analysis of the data into an EPA guidance document
Provide a public comment period for the guidance document and associated methods
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Useful References
EPA test method guidelines
http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guide
lines/series810.htm
List of EPA registered disinfectants
http://www.epa.gov/oppad001/chemregindex.htm
MLB Standard Operating Procedures:
http://www.epa.gov/pesticides/methods/atmpa2z.htm
Published summary of efficacy test methods:
Tomasino, S.F. 2013. Development and assessment of
disinfectant efficacy test methods for regulatory purposes.
American Journal of Infection Control. 41, 572-576.
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EPA Contacts
Stephen Tomasino (methods): [email protected]
Rebecca Pines (methods): [email protected]
Emily Mitchell (regulatory): [email protected]
Mark Perry (regulatory): [email protected]
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