This datasheet provides background historical information on major accidents in the onshore and offshore oil and gas production and process industries, to serve as background for QRA studies. The focus of this datasheet is on presenting an overview the range of accident types and their relative frequency of occurrence, rather than on absolute frequencies. Attention is focused on major accidents, taken to be those that have resulted in significant numbers of fatalities, asset damage and/or environmental pollution. Frequencies have been estimated for several of the accident types most commonly addressed in QRAs in other datasheets of this set.