Valero Energy Corp. said the fire at its McKee refinery in the Texas panhandle - ranked the 44th-largest refinery in the United States by the Department of Energy - could have started at the refinery's propane de-asphalting unit, which uses propane to extract refinable materials from the tarry residue generated by a crude oil unit.
Media reports indicated that more than 400 workers were evacuated from the refinery after the explosion.
Critically Injured Workers Now In 'Good Condition'
According to Valero Corp. spokesperson Mary Rose Brown, two of the three employees who initially were listed in critical condition are now "in good condition and are anxious to go home." One of them was expected to be released Feb. 20. A third worker is still in serious but stable condition, she said.
The rest of the injured employees already have been released from nearby hospitals, she added.
The refinery will continue to be shut down while Valero's emergency response team, in conjunction with representatives from OSHA and the Chemical Safety and Hazard Investigation Board (CSB) assesses the damages.
"The refinery remains highly sensitive and access to the refinery continues to be restricted to those individuals who are deemed to be critical to the incident investigation and repair and recovery efforts," Brown said.
CSB's Third Valero Investigation
CSB has deployed an investigative team to assess the circumstances of the incident to determine if a larger investigation is necessary.
This is not the first time the CSB has investigated a Valero refinery.
In November 2006, the CSB completed a 1-year investigation of the asphyxiation deaths of two workers at the Valero Delaware City refinery. (See "CSB: Valero Deaths Preventable.")
In May 2006, a CSB team did an assessment of a fire in the diesel hydrotreater unit at the Valero St. Charles refinery in Louisiana. No one was injured or killed during the fire. (See "CSB Finishes Valero Blast Investigation; Cause of Pipe Rupture Still Unknown")