We analyzed audio recordings of telephone calls between emergency departments (EDs) and poison control centers (PCCs) in order to describe the information requirements for health information exchange. Analysis included a random sample of 120 poison exposure cases involving ED-PCC communication that occurred during 2009. We identified 52 information types characterized as patient or provider information, exposure information, ED assessment and treatment/ management, or PCC consultation. These information types constitute a focused subset of information that should be shared in the context of emergency treatment for poison exposure. Up to 60% of the information types identified in the analysis of call recordings can be represented using existing clinical terminology. In order to accomplish standards-based health information exchange between EDs and PCCs using data coded according to a standard clinical terminology system, it is necessary to define appropriate terms, information models and value sets.