The primary focus of the Office of Pesticide Program's Microbiology Laboratory is the evaluation of EPA-registered antimicrobial products with public health claims – products used to kill or suppress the growth of pathogenic microorganisms on inanimate objects and surfaces. Applied research on the development and standardization of laboratory methods used to determine the efficacy of antimicrobials is a key priority for the OPP Microbiology Laboratory. The laboratory is instrumental in advancing the science of antimicrobial product testing and provides technical expertise to standard-setting organizations and various agency stakeholder groups. The laboratory provides support to other agency offices on Homeland Security initiatives and is registered with the CDC/USDA Select Agent Program.
Location: EPA's Environmental Science Center at Fort Meade, Maryland
- Antimicrobial Testing Program
The OPP laboratories have responsibility for conducting formulation analyses and efficacy evaluations of selected categories of antimicrobial pesticides under the Antimicrobial Testing Program. Federal or state inspectors collect samples post-registration, or the registrants provide them to the laboratory voluntarily. The Analytical Chemistry Branch conducts a formulation analysis of the active ingredients to determine compliance with certified limits. Once the sample is found to be in compliance, the Microbiology Laboratory Branch evaluates the efficacy of the product based on the label claims. The laboratory has capability to test a wide variety of product formulations (e.g. liquids, sprays and towelettes) against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica, Escherichia coli, Klebsiella pneumoniae, Mycobacterium bovis BCG, Bacillus subtilis, Clostridium sporogenes and Clostridium difficile. These microorganisms are associated with claims for hospital disinfectants, sanitizers, tuberculocides and sterilants. The laboratory operates under Good Laboratory Practices and follows Standard Operating Procedures for testing. In most cases, the SOPs are based on standard methods adopted by AOAC International or the American Society for Testing and Material and represent the laboratory’s interpretation of the methods. Once testing is complete, the laboratory develops a report and shares the results with the OPP Antimicrobials Division.
- Anthrax Decontamination
In response to the anthrax attacks, OPP received numerous requests for emergency exemptions that would permit the use of antimicrobial chemicals for decontamination of buildings and their contents. OPP’s Microbiology Laboratory evaluated four chemicals (sodium hypochlorite, aqueous chorine dioxide, hydrogen peroxide/peracetic acid, and hydrogen peroxide/quaternary ammonium compounds/organosiline) using the EPA accepted method, the AOAC Sporicidal Activity Test (SAT). The laboratory determined that sodium hypochlorite (bleach) and aqueous chlorine dioxide were effective on hard surfaces against spores of Bacillus subtilis. As a result, these products were used as part of the anthrax remediation efforts, including at the Hart Senate Office Complex on Capitol Hill.
- Sporicidal Methods Research Project
The need to improve performance testing for sporicides became an EPA priority following the intentional release of anthrax spores into indoor environments. In the fall of 2003, the OPP Microbiology Laboratory initiated research, in collaboration with other federal laboratories (US Army, FDA, and Air Force), to explore new methodologies for efficacy testing of sporicides. The focus of the research is to determine the most suitable method and surrogate for evaluating antimicrobial products proposed for remediation of buildings contaminated with anthrax spores.
- CDC Laboratory Response Network
The OPP Microbiology Laboratory has obtained full registration under the CDC Select Agent Rule (Public Health Security and Bioterrorism Preparedness and Response Act of 2002). The laboratory is in the preliminary phases of joining the CDC Laboratory Response Network (LRN) , a nationwide laboratory network for food, veterinary, plant health, and water quality that integrates existing Federal and State laboratory resources and standardizes diagnostic protocols and procedures. The LRN deals primarily with public health needs. As a referral laboratory within the LRN, the Microbiology Laboratory would be limiting its work to analysis of Bacillus anthracis environmental samples.