Probabilistic safety methods, which are being used in the chemical, manufacturing, and energy industries, create a basic need for input data CM failure rates of the mechanical, electrical, instrumentation and control. and other components that comprise the engineering systems in a facility Some companies have data stored and easy to retrieve Other companies hire consultants who use their own databases to perform safety assessments For analysts who do not have either of these options available, this article presents data sources that are retrievable from the literature The accessibility of data documents via the Internet is also described (C) 2010 American Institute of Chemical Engineers Process Sal Prog 29 236-241, 2010