At approximately 1:00 p.m. on the 23rd October 1989 Phillips’ 66 chemical complex at Pasadena, near Houston (USA) experienced a chemical release on the polyethylene plant. A flammable vapour cloud formed which subsequently ignited resulting in a massive vapour cloud explosion. Following this initial explosion there was a series of further explosions and fires.

The consequences of the explosions resulted in 23 fatalities and between 130 – 300 people were injured. Extensive damage to the plant facilities occurred.

The day before the incident scheduled maintenance work had begun to clear three of the six settling legs on a reactor. A specialist maintenance contractor was employed to carry out the work. A procedure was in place to isolate the leg to be worked on. During the clearing of No.2 settling leg part of the plug remained lodged in the pipework. A member of the team went to the control room to seek assistance. Shortly afterwards the release occurred. Approximately 2 minutes later the vapour cloud ignited.

KEY ISSUES:
• MAINTENANCE PROCEDURES
• LEAK / GAS DETECTION
• PLANT LAYOUT
• PERMIT TO WORK SYSTEMS
• ACTIVE / PASSIVE FIRE PROTECTION
• WARNING SISGNS
• EMERGENCY RESPONSE / SPILL CONTROL

Image Credit: Houston Chronicle