Investigators with the United States Chemical Safety and Hazard Investigation Board (CSB) suspect a flammable cloud that formed over two tank trucks may be the cause of a flash fire at an oilfield waste recovery facility south of Houston TX that killed two workers and injured three others Jan 13, 2003.
“We are operating right now on the possibility that a flammable cloud formed over the two tank trucks shortly after their arrival at the site, causing what we call a ‘deflagration’ or flash fire of the vapor,” said Carolyn Merritt, CSB chairman.
The accident occurred at the BLSR Operating Ltd petroleum storage and separation facility on Route 521 in Rosharon TX near Houston, where trucks owned by T&L Lease Services, Alvin TX, were on an outdoor cleaning rack.
The dead, identified only by their ages 22 and 36, were employees of BLSR, which operates a tank farm storage facility on Caldwell Ranch in an oilfield, Gingrich said.
Lead investigator John Vorderbrueggen noted that the incident was not technically an explosion, which generally occurs in an enclosed space. In this case, the fire occurred under an open-air shed.
Eyewitnesses have confirmed that the diesel engines of the trucks began racing moments before the deflagration, indicating that flammable vapors were entering the air intakes.
Investigators are now focusing attention on interviewing the truck drivers, both of whom survived the accident, as well as plant employees and managers. They will also analyze residues of oilfield waste material from the truck and the plant site to determine the source of highly flammable fumes that are suspected in the accident.
Investigators emphasize that the diesel engine blocks did not explode, but the flash fire did destroy the cabs, tires, hoses, and other combustible truck components. Neither the waste tanks nor the fuel tanks ignited, leading investigators to believe that flammable vapors burned in a rapid hot fire. Investigators say BLSR has been cooperating with their inquiries.
The CSB is an independent federal agency charged with determining root causes of chemical accidents and making recommendations to prevent their recurrence. CSB investigations generally take six to 12 months to complete, although safety alerts may be issued more rapidly as needed.