IE Safety Abbreviation

Initiating Event

The minimum combination of failures or errors necessary to start the propagation of an incident sequence. It can be comprised of a single initiating cause, multiple causes, or initiating causes in the presence of enabling conditions. (The term initiating event is the usual term employed in Layer of Protection Analysis to denote an initiating cause or, where appropriate, an aggregation of initiating causes with the same immediate effect, such as "BPCS failure resulting in high reactant flow".