Mobil worker error caused refinery explosion, Fire Department reports.

A Mobil Oil Corp. employee opened a valve on a pipeline at the Torrance refinery, allowing flammable gas to escape and find a source of ignition, causing a fire and explosion last month, according to a report released by Torrance Fire Department last week.

The Oct. 19 fire and explosion burned 28 people, four of them critically. All of the injured were employees of Fairfax, Va.-based Mobil, or Mobil's subcontractors, Carson-based IST Mechanical Inc. and Houston-based Serv-Tech Inc. All were released from South Bay hospitals this month.

According to Torrance Fire Battalion Chief Kennith Hall, Mobil employees Roy Carlisle and Leslie Lewis mistakenly thought the pipeline was closed off when Carlisle opened the valve. Carlisle and Hall did not "walk the pipe" to check if it was sealed, Hall said.

Lewis had told Carlisle to open the pipe through radio contact, according to the report. The report describes Lewis and Carlisle as head operators of the alkylation unit, which uses deadly hydrofluoric acid.

Hydrofluoric acid, which if spilled has the potential of forming a lethal cloud, was not involved in the incident, although the pipeline was connected to the aklylation unit.

Vapor cloud forms

According to the report, Carlisle "had just begun opening the valve when he became aware of a 'hydrocarbon' odor. He said he investigated and saw a white vapor cloud forming on the ground below him. He said he immediately began closing the pipe when the explosion and fire occurred."

A combination of butane, butylene and propane gas escaped from the valve, according to the report. Fire officials believe a process heater ignited the gas, although there were several sources of ignition near the leak, including unit heaters and welding equipment that was in use, according to the report.

Barry Engelberg, Mobil spokesman said in a prepared statement, "Mobil has received the Torrance Fire Department report and will review it very carefully and use it as further input to its own exhaustive investigation, which we intend to conclude very shortly."

He continued, "The refinery has already invested 2,000 man-hours in its own investigation. We are not only looking at what happened, but why it happened and most importantly, what can be done to prevent it from happening again."

He added, "Our safety record is in the top percentiles in the industry."

Cal-Osha probes too

Hall said the Fire Department's investigation was focused on whether the fire was accidental or set intentionally. The California Occupational Safety and Health Administration is investigating whether unsafe workplace practices led to the explosion, he said.

The agency will issue a report on the incident in the next few weeks, said Rick Rice, Cal-Osha spokesman. Engelberg said Mobil will issue a report to Cal-Osha.

Investigators are trying to determine whether Mobil or the two subcontractors involved in the incident, IST Mechanical and Serv-Tech, violated any California workplace regulations, Rice said.

Mobil and the two subcontractors whose workers were injured in explosion have all been involved in incidents involving gas or hot liquid releases injuring workers in the last five years.

Rice said both Mobil and Serv-Tech had been cited in the past for a violation of section 6815 of the California Code of Regulations which requires that lines carrying gas or liquid be de-pressurized before the lines are opened.

Engelberg, Mobil spokesman, said he had "no information" about whether the prior incidents involved Mobil.

Jan Knapp, office manager and controller at IST Mechanical, said, "At this time, we're not making any statements" regarding the explosion and declined to comment on past incidents.

A Serv-Tech spokeswoman declined to comment.

Earlier incidents cited

According to Cal-Osha records, all three companies have been involved in incidents in which workers were injured due to gas or hot liquid escaping from lines.

* On Feb. 12, 1994, two Mobil employees were burned and one hospitalized when there was a release of petroleum coke and hot water when they were removing a piping spool from a pump on the coker unit.

* On Jan. 13, 1991, a Mobil employee was burned when she walked past a coke drum which was being opened and was spewing hot water and steam.

* On Nov. 3, 1991, IST Mechanical employees were working on a flange on a pipeline at Mobil when a hydrocarbon cloud was released. Three were treated for chemical burns of the hands and feet and inhalation of vapors.

* On June 5, 1993, Serv-Tech employees were opening a line attached to a piece of equipment at a facility on Anaheim Street in Wilmington, when hydrocarbon vapors were released. Two employees were treated for "asphyxia," according to the report.