Validating the performance of the kill step is a critical procedure to ensure the safety of processed foods, and it is a mandatory requirement to comply with food safety regulations, including U.S. F.D.A Food Safety Modernization Act (FSMA). Due to their capability to generate real-life, “unquestionable” validation data, surrogate organisms offer the food industry an invaluable tool to conduct in-plant validation studies. Surrogate organisms are non-pathogenic microorganisms that mimic the resistance of foodborne pathogens (Salmonella, Listeria, E. coli 0157:H7) when exposed to different kinds of stress like heat. Due to their safety, they are used directly at plant- or pilot-scale to simulate contaminations and validate the process. This presentation will provide an update on historical and current utilization of non-pathogenic surrogate indicators, as well as discuss emerging surrogate applications. Experimental results will be presented that evaluated the appropriateness of surrogate organisms for various processing, pathogen and product configurations. A specific focus will be placed on emerging thermal applications, including fruit drying, baking of meat products like patties and blanching steps for vegetables. Recent R&D work conducted to select an appropriate surrogate candidate for HPP validations will also be presented. Real-life case studies will be developed presenting the technical and logistical advantages of using dried and ready-to-use surrogate organisms to conduct in-plant validation studies. As a final part, the presentation will provide more details about how surrogates can help food companies quantify the performance of their cleaning & sanitation procedures, including equipment cleaning (e.g. CIP) and the factory environmental cleaning programs.