Another change was that the importance of process safety -- focusing on an operation as a whole, rather than small individual accidents -- was one of the lessons of the Texas City disaster and has now been emphasised in the drilling operations as well as BP's refineries, Mr Morrison said.

CNN: BP claims it now leads the way on safety

The Deepwater Horizon disaster followed other failures including a leak from a pipeline in Alaska in 2006 and the Texas City refinery explosion in 2005, which killed 15 people in one of the US's worst industrial accidents of recent years.

CNN: BP claims it now leads the way on safety