Between 1996 and 2008 it is estimated that there have been 173 loss of primary containment (LOPC) incidents reported in RIDDOR that can be attributable to ageing plant. This represents 5.5% of all loss of containment events. The limited information provided in RIDDOR about the underlying causes means that it is difficult to identify which events may be age related: the actual number could be much higher than that quoted here. Across Europe, between 1980 and 2006, it is estimated that there have been 96 incidents reported in the MARS database relating to major accident potential loss of containment which are estimated to be due to ageing plant. This represents 28% of all reported ‘major accident’ loss of containment events in the MARS database and equates to an overall loss of 11 lives ,183 injuries and over 170 Million € of economic loss. As the MARS data provides the more detailed and comprehensive insight into the incidents and causal factors and is specifically related to potential major accident hazard events, it is considered that this represents a more realistic indication of the extent and severity of ageing plant and its contribution to major accidents. This leads to the conclusion that ageing plant is a significant issue.