In 2023, the ITRC Contaminants of Emerging Concern (CEC) Framework was published to help environmental regulatory agencies and other stakeholders identify, evaluate, and manage CEC's while acknowledging uncertainties in their environmental fate and transport, receptor exposure, and/or toxicity. Such an approach can be conducive to improved allocation of regulatory response resources and provide a foundation for communicating potential risk to stakeholders. The ITRC framework is comprised of a white paper and four associated fact sheets. In the white paper, CEC are defined as: "substances and microorganisms including physical, chemical, biological, or radiological materials known or anticipated in the environment, that may pose newly identified risks to human health or the environment." The framework is meant to help environmental regulatory agencies and other stakeholders by providing examples of CEC monitoring programs and guiding the user through the process of identifying CEC key characteristics, how to communicate real and perceived risk from CEC to the public, and how laboratory analytical methods can be used in the identification process.The ITRC CEC training presents this entirely new framework for identification, prioritization, and communication of CEC. This course includes the following topics:An overview of the framework, how and why it was developed, the factors that influence the creation of CEC management units at the state level, and a listing of existing CEC monitoring programs.A discussion of key variables that may be used as criteria to identify and prioritize CEC for response actions. This portion of the course includes a case study that illustrates how the identification and prioritization process works with an "unknown" chemical CEC.Practices and methods for stakeholder messaging and how to share incomplete information on CEC that could impact human health and the environment. This portion of the short course builds upon the ITRC Risk Communication Toolkit by providing additional detail addresses communications plans, message maps, and audience identification.A paradigm for how laboratory methods can be used to identify CEC ranging from: "Is compound X in the sample and at what concentration?" (i.e., known knowns) to"Which compounds from the list are in this sample?" (i.e., known unknowns) to"What is in the sample?" (i.e., unknown unknowns). CEC are typically compounds or substances whose occurrence or effect is unknown but may or may not be understood through similar compounds or substances. This module includes a discussion of the use of targeted and untargeted analysis to identify a CEC.Participants will learn the elements of the CEC framework and gain an understanding of the framework application from case studies. Participants are encouraged to review the ITRC CEC Framework prior to the class. To view this archive online or download the slides associated with this seminar, please visit http://www.clu-in.org/conf/itrc/CEC_052124/