Standard HSE investigation techniques were used in the investigations. These included analysis of the events that took place and the causes (events and causal factors analysis). The investigation findings were compared against the following five themes.
Whether statutory legislative requirements (e.g. Schedule 2 of COMAH re safety management systems) had been met.
Whether best practice/internal guidance had been followed. For example whether the approach taken to the management of health and safety on-site was consistent with the POPMAR model approach specified in the HSE publication HSG65 – "Successful Health and Safety Management" and whether the BP Grangemouth on-site rules/procedures and guidelines had been followed.
Whether the claims made in the relevant COMAH/CIMAH safety report where appropriate (e.g. COMAH safety report for the FCCU) could be supported by the findings of the investigations.
Whether BP’s Group Health, Safety and Environmental Policy and Expectations were being met.
Whether there was a history of previous incidents of a similar nature at BP Grangemouth or within the wider BP organisation from which lessons could have been learned and actions taken.
In addition consideration was given to whether the findings and recommendations outlined in the HSE reports of other major accidents (such as those at Texaco and Associated Octel) and other published information had been noted by BP and implemented where appropriate.