Although meticulous work is often clone to determine failure probabilities of Safety Instrumented Systems for Quantitative Risk Assessments (QRAs), the work done to determine failure probabilities of humans performing specific tasks are often less rigorously performed. Yet, human reliability data is just as important to the quality and accuracy of the QRA as non-human failure probabilities. The problem lies in the lack of availability of statistically reliable human failure probabilities for various tasks within the process industries. This article will present and analyze the strengths and weaknesses of a variety of sources of such data. The various methods of data collection and analysis will be discussed and as will the quality and applications of each methods' data output. More specifically, emphasis will be placed on discussion of the US Nuclear Regulatory Commission's Human Event Repository and Analysis program and the possible applicability and worth of the program to the process industries. This presentation is based on work done for the Center for Chemical Process Safety's Human Reliability Project. (C) 2009 American Institute of Chemical Engineers Process Saf Prog 29: 123-126, 2010