Surviving witnesses report seeing a spout of liquid and vapors erupting from a 100-foot tower in an area of the refinery known as an isomerization unit just before the explosion. Investigators from the U.S. Chemical Safety Board are asking why the pressure relief system allowed flammable liquids and vapors to vent to a "vent stack," instead of a much safer and more commonly used flare system that burns the material.
Turns out this was not the first time plant owners had been alerted to this problem:
In 1992, the Occupational Safety and Health Administration cited BP predecessor Amoco Oil Co. for using equipment, including a splitter — the same type of machinery at the center of the current investigation — in a manner "that allowed toxic gases to vent to the atmosphere ... thus exposing employees to flammable or toxic gases." The four-month investigation was part of a broader initiative launched by OSHA after a string of fires at industrial facilities.Facility Siting
To correct the problem, OSHA recommended that Amoco reconfigure the unit so that liquids and vapors discharged go to a flare, or set up air monitors. The company settled the case, which cited 15 violations and fined the company initially $50,000 in 1994, according to OSHA records, but it is unclear whether they followed the agency's recommendation, since it is not required.
BP spokesman Bill Stephens said an initial review of the company's records "indicates that OSHA withdrew that alleged violation."
OSHA records suggest that the plant fixed the problem in May 1992, and the case was settled in August 1994. At some later date, the citation was deleted and the fine was withdrawn. Further details were unavailable late Thursday.
The OSHA violation is supported by anecdotal reports from former employees who worked on the isomerization unit over the years. The unit was constructed from another unit in the mid-1980s, according to state permits. The vent stack has been in place since the mid-50s, but BP said it replaced it in 1997.
Stephens said the stack and a collection tank at its base called the blow-down drum are part of an emergency pressure release system designed to redirect liquids and vent gases.
A longtime employee on the unit said the stack and drum has had problems over the years.
"All of that stuff should have been taken out of that blow-down drum and put to a flare system," said Wydell Dixon, an operator on the isom unit from 1975 to 1999. Dixon later sued and settled with Amoco over an employment dispute.
Meanwhile, there was another serious problem about which plant owners had plenty of warning: the location of a temporary office trailer only 100 to 150 feet away from the vent stack that exploded, many of whom were inside the trailer. Other major refiners and BP Amoco guidelines call for trailers to be located far from refinery equipment as possible. Some also call for the evacuation of non-essential personnel before a hazardous unit is restarted, one of the most dangerous times of refinery work.
OSHA's Process Safety Management standard calls on companies to perform a "process safety analysis" that addresses "facility siting" issues, such as where office space and control rooms should be located and how blast-resistant they must be.
The Center for Chemical Process Safety published Guidelines for Facility-Siting and Layout in 2003, which also addresses the issue:
Offices and warehouses should be far enough away from ventilation stacks and process units to be "outside of vapor cloud explosion damage areas." Those guidelines also say the typical spacing requirement between offices and equipment is 200 feet.Ten years ago, there was an explosion at a Pennzoil plant in Rouseville, PA in which three of the five workers killed were in in tool and break trailers near the explosion.
And the plot thickens:
Jacobs, the engineering firm that lost 11 employees in the Texas City explosion, was a contractor at the Rouseville plant. Jacobs executives refuse to comment on trailer placement or contract worker safety.Indeed.
In the Rouseville case, a Jacobs safety manager filed a legal affidavit saying the "placement of trailers" at the Pennzoil plant was done "in conscious indifference and disregard to the safety and welfare of workers at the plant." Federal investigators castigated Pennzoil, saying lives could have been saved in Pennsylvania had the trailers been farther from the volatile area.
Two years later, Pennzoil said it had developed a trailer permitting process that would never again allow the mobile break rooms, offices, laundry facilities or clothing-changing stations to be put in the most dangerous areas of the plant.
Lawyers looking at the Texas City devastation find it hard to understand why trailers are again an issue a decade later.
- Workplace Safety Enforcement: A Tale of Two Countries, April 5, 2005
- Transparency? Or PR Savvy?, March 26, 2005
- BP In California: "callous and intentional noncompliance purely for economic reasons", March 24, 2005
- BP, site of fatal explosion, is Nation's Leader in Accidents, March 24, 2005
- At Least 14 Dead, Hundreds Injured In Huge Refinery Explosion, March 23, 2005