The Phillips 66 Incident Tragedy in Pasadena, Texas

According to the OSHA investigation report, the reactor was undergoing a regular maintenance procedure for the removal of a solidified polyethylene blockage on three of the six reactor settling legs. The procedure called for the isolation of the 8-inch valve and the removal of the compressed air hoses used to operate the valve. [7] 

The maintenance crew had partially disassembled the leg and managed to extract a polyethylene log from one section of the leg. However, part of the log remained lodged in the pipe below the 8-inch isolation valve. Witnesses stated that a mechanic went to the 

After the explosion, investigators confirmed that the 8-inch DEMCO block valve was open at the time of the accident. Furthermore, tests showed that the compressed air hoses were improperly connected in a reversed position. This unauthorized step during maintenance 

The release of hydrocarbons from the polyethylene reactor occurred as a result of a violation of the procedures that are designed to provide three levels of protection.. . . The investigation does not speculate on who violated the procedure and for what reason.. . . The magnitude of the damage at the site and the lack of eyewitness information prevented the company from making such conclusions.. . .  

The accident was caused by a violation of well established and understood procedures, and other possible causes such as design, construction, quality of materials and established procedures were not implicated. [8] 

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