The use of generic failure frequencies in QRA: the quality and use of failure frequencies and how to bring them up-to-date.

Quantitative Risk Assessment (QRA) is a method which is often used in the chemical industry and, in some countries, also in land-use planning. In QRA calculations the frequency of an accident scenario is most often assessed by a generic failure frequency approach. The credibility and validity of the failure frequencies used in the Netherlands for land-use planning is evaluated by means of an historical review. Furthermore, the possibility is presented how these generic data can be revised and updated.