A sombre reminder of everything which can go wrong when barriers break down and management looks the wrong way is provided by the investigation into this disaster.
The accident occurred when the raffinate splitter and blowdown drum were overfilled during a start-up. A large volume of liquid hydrocarbons escaped and formed a vapour cloud, which ignited.
In addition to the loss of life, the explosion and subsequent fire caused huge material damage to the refinery and its surroundings.
The direct and underlying causes of the incident were uncovered through a detailed inquiry by the US Chemical Safety and Hazard Investigation Board (CSB).
At the CSB’s instigation, BP also appointed an independent safety review panel headed by James Baker III, in part to assess the company’s overview of safety, its safety culture, and established barriers.
The direct cause of the accident was that metering equipment in the splitter failed to function as intended. An error meant it was not defined as safety-critical, and both testing and maintenance were deficient.
A number of complex reasons explained why this could happen, and these related in part to lack of management involvement and an inadequate grasp of the instrumentation’s key role.
The conditions criticised by the Baker panel, which included a lack of maintenance, had also developed in a negative direction over time.
This was attributed to extensive cost cuts which had been implemented in earlier years without paying sufficient attention to the possible consequences for safety.
In addition, the top management was perceived to have been more concerned with personal injury statistics than with factors influencing major accident risk.
Both the CSB and the Baker inquiry concluded that safety-critical equipment which is not satisfactorily maintained will contribute sooner or later to “an accident waiting to happen”.