Methods for Disinfectant and Sporicidal Products

AOAC has successfully completed a 5-year contract with the U.S. Environmental Protection Agency-Office of Pesticide Programs (EPA/OPP). The contract was designed to facilitate and implement editorial and procedural modifications of existing methods found in Chapter 6 (Disinfectants) of the Official Methods of Analysis of AOAC INTERNATIONAL (OMA) and the development and validation of new methods. Since the contract signing on July 12, 2007, the effort has resulted in numerous revisions to several AOAC Official MethodsSM, the publication of nine papers, and the use of stakeholder meetings and expert review panels (ERPs) to seek opinion and consensus on improving methodologies.

Key to the effort was input from the AOAC Methods Committee on Antimicrobial Efficacy Testing and from stakeholders, who were critical to the editorial review process and consensus-building activities.

The methods were revised editorially to improve consistency (for example, cautions and notes, media preparation, and operating technique). In addition, minimum and maximum log density values were established for test microbes on inoculated carriers and retesting guidance was added. Each method was revised at least twice in the last 5 years. Revised methods include 955.14955.15, and 964.02 (Use-Dilution Methods); 960.09 (Germicidal and Detergent Sanitizing Action of Disinfectants); 961.02 (Germicidal Spray Products as Disinfectants); 965.12(Tuberculocidal Activity of Disinfectants); 966.04 (Sporicidal Activity of Disinfectants Test); and 2008.05 (Three-Step Method). The revised methods are available on the OMA Online at

Clostridium difficile

The ERP on Clostridium difficile was formed to establish performance requirements and overall direction for validation of an AOAC method for production of spores and testing the efficacy of disinfectants against C. difficile. The ERP established a fitness-for-purpose statement, identified recovery and enumeration media, and validated two sporulation protocols for producing high-quality and high-titer C. difficile spores. Although the EPA contract ended January 11, 2013, panel members agreed to collaborate on two papers: a white paper detailing the ERP process, objectives, and outcome, and a collaborative study manuscript comparing the two sporulation protocols.

Formulation Chemistry of Disinfectants

The contract work also included an LC method for the determination of mixed phenolic compounds. The successful single-laboratory validation (SLV) study was used to seek a full AOAC collaborative study validation of the method. The method was approved as First ActionOfficial MethodSM 2011.26 and is available on OMA Online.