Towelettes may be evaluated using liquid directly expressed from the towelette. difficile spray formulations may be evaluated as a liquid by removing/dispensing an appropriate amount of liquid from the spray device. The test methodologies described below may be used for testing the efficacy of water soluble powders or liquid formulations against C. difficile claims may be added to liquid, spray, and towelette formulations of a sterilant, sporicide, or hospital disinfectant product provided that the product meets the performance criteria for testing outlined in the most current version of Antimicrobial Efficacy Test Guidelines – 810.2100: Sterilants – Efficacy Data Recommendations or 810.2200: Disinfectants for Use on Hard Surfaces – Efficacy Data Recommendations. difficile spores to be public health claims for which the Agency must receive, review, and approve appropriate efficacy data in order to evaluate such claims for possible approval. The Agency recognizes the potential public health implications of these spores in healthcare settings and the importance of having antimicrobial products with demonstrated efficacy against C. difficile is an anaerobic spore-forming bacterium and a frequent cause of hospital-acquired infections. Data submission procedures for efficacy data.Test procedures for developing product efficacy data supporting C.This guidance may be updated in the future. The Agency will evaluate any proposed method modifications for appropriateness on a case-by-case basis. modifications to the recommended test methodology) to the Agency for assessment. Registrants and applicants may propose and submit alternative practices (e.g. This guidance is not binding on EPA or any outside parties, and EPA may depart from the guidance where circumstances warrant and without prior notice. The Agency’s response to comments and other documents associated with this action are available in docket EPA-HQ-OPP-2016-0753 at This guidance supersedes the Agency’s previous guidance for the efficacy evaluation of antimicrobial pesticides registered or proposed for use against C. difficile spores on hard, non-porous surfaces.ĮPA solicited comments on the clarity of the test methods and the regulatory guidance in December 2016. These test methods and guidance provide a framework for registrants who seek to make a claim for antimicrobial pesticide products to control C. difficile), as well as regulatory guidance for pesticidal claims for those products. This webpage provides test methods for evaluating the efficacy of antimicrobial pesticides against spores of Clostridium difficile ( C.