By Julian O'Halloran
BBC Radio 4, The World Tonight
The report will cap a year of bad news for BP
British oil giant BP is expected to be heavily criticised by US safety investigators over a refinery disaster that killed 15 workers.
BP's Texas City plant, south of Houston, was hit by a fatal explosion in 2005, which also injured 180 people.
A report by the US Chemical Safety Board on Tuesday is set to conclude that there were deep-seated failures in the way BP dealt with safety.
The report is likely to highlight cost-cutting measures at the refinery.
BP has denied that budget cuts were to blame for the Texas City disaster.
The report is expected to allege that over several years warning signs of impending catastrophe at Texas City were not heeded, and that BP chief executive Lord Browne and directors "did not exercise effective safety oversight".
The report will cap a year of bad news for BP, including an oil spill in Alaska, which has seriously damaged the company's image.
In January, BP announced that Lord Browne would step down in July, 17 months earlier than planned.
The chairman of the US Chemical Safety Board, Carolyn Merritt, says not enough had been done at the highest levels of BP to check on how budget cuts had affected safety.
"The big problem is that we did not find any evaluation being done by anybody at any level that said these cuts were impacting safety," says Ms Merritt.
She told Radio 4's The World Tonight that investigators had begun to suspect much wider safety problems at BP soon after starting their inquiry in 2005.
"BP had said in their early reports that this was a one-off, that Texas City was unique in these problems. From my experience and the experience of our investigators we didn't believe that could be the case," says Ms Merritt.
She said suspicions were raised when the investigation team found evidence of "failure to identify very serious near-miss accidents... and problems with equipment that was not repaired".
In a previous safety report on BP's safety culture, the company admitted "management system failures".
It said it was trying to improve safety at its refineries.
'Never go back'
BP engineer Kristof Harris was injured when a mobile office sited near the seat of the explosion was destroyed. A dozen of his workmates were killed.
He told the BBC that he had had 14 operations and was on pain-killers and anti-depressants.
He has a badly damaged foot and says that what he misses most is playing ball games with his children.
"My life was sports, on my own and with my kids," says Mr Harris.
"I have a psychiatrist and I tell her that I live about 10% of the life that I used to live before the explosion. So I've lost 90% of my life in the last 18 months."
"What happened here was something that should never have happened."
Mr Harris says he still feels loyalty to BP, but he is not certain he can ever go back to work at the plant.
"I had 12 people that died, and many more were mangled. My job is to keep them safe, and I was betrayed by mistakes... and that's very hard to deal with," he says.
Trade union official Sonny Sanders, of the United Steel Workers, says he will be cautious about trusting BP in the future.
He says to restore his faith in the company he would want a clear statement from BP's Lord Browne about the role he played in cost-cutting policies.
"If the decision was made at his level to cut budgets throughout BP and its holdings worldwide, then Lord Browne is culpable in regards to this explosion," says Mr Sanders.
"If he was not directly responsible then he is at least a party to these decisions and should be held responsible because he is the CEO of the company."
BP refused BBC requests to visit the Texas City plant and to interview a senior executive about the refinery disaster.
Listen to Julian O'Halloran's full report on Monday's edition of Radio 4's The World Tonight