Quantification of ignition probabilities and database

Two approaches exist for estimating ignition probabilities:

• quantification using databases ;

• quantification using mathematical models.

The most common approach to hazard studies is to use databases. As with other parameters (e.g. leak frequency), the database used must be justified. Apart from the reputation of the source used, it is important to ensure that the values extracted from the database are representative of the case studied. The probabilities reported in databases are often associated with criteria or conditions justifying their area of validity. In the context of a hazard assessment, before using databases to estimate ignition probabilities, you need to ask yourself the following questions:

• What parameters are taken into account in the databases that report ignition probabilities?

• What are the weaknesses of quantifying the probability of ignition using databases?

• Which databases are known to the Administration (DREAL and/or DGPR)?