The facility produced approximately 1.5 billion pounds per year of high-density polyethylene (HDPE), a plastic material used to make milk bottles and other containers. The HCC facility employed 905 company employees and approximately 600 daily contract employees, who were engaged primarily in regular maintenance activities and new plant construction.
The incident started at approximately 1:00 PM local time on October 23, 1989, at 1400 Jefferson Road, Pasadena, Texas 77506. A massive and devastating explosion and fire ripped through the Phillips 66 Company's Houston Chemical Complex (HCC), killing 23 persons -- all working at the facility -- and injuring 314 others (185 Phillips 66 employees and 129 contract employees). In addition to the loss of life and injuries, the explosion affected all facilities within the complex, causing $715.5 million worth of damage plus an additional business disruption loss estimated at $700 million. The two polyethylene production plants nearest the source of the blast were destroyed, and in the HCC administration building nearly 0.5 mile away, windows were shattered and bricks ripped out. The initial explosion was equivalent to an earthquake registering 3.5 on the Richter Scale and threw debris as far away as six miles.
The accident resulted from a release of extremely flammable process gases that occurred during regular maintenance operations on one of the plant's polyethylene reactors. More than 85,000 pounds of highly flammable gases were released through an open valve. A vapor cloud formed and traveled rapidly through the polyethylene plant. Within 90 to 120 seconds, the vapor cloud came into contact with an ignition source and exploded with the force of 2.4 tons of TNT.
The initial response was provided by the Phillips 66 Company fire brigade which was soon joined by members of the Channel Industries Mutual Aid association (CIMA). Cooperating governmental agencies were the Texas Air Control Board, the Harris County Pollution Control Board, the Federal Aviation Administration (FAA), the U.S. Coast Guard, the Occupational Safety and Health Administration (OSHA) and the U.S. Environmental Protection Agency (EPA).
The fire-fighting water system at the HCC was part of the process water system. When the first explosion occurred, some fire hydrants were sheared off at ground level by the blast. The result was inadequate water pressure for fire fighting. The shut-off valves which could have been used to prevent the loss of water from ruptured lines in the plant were out of reach in the burning wreckage. No remotely-operated fail-safe isolation valves existed in the combined plant/fire-fighting water system. In addition, the regular-service fire-water pumps were disabled by the fire which destroyed their electrical power cables. Of the three backup diesel-operated fire pumps, one had been taken out of service, and one ran out of fuel in about an hour. Fire-fighting water was brought in by hoses laid to remote sources: settling ponds, a cooling tower, a water main at a neighboring plant, and even the Houston Ship Channel. The fire was brought under control within about 10 hours as a result of the combined efforts of fire brigades from other nearby companies, local fire departments, and the Phillips 66 foam trucks and fire brigade.
All search and rescue operations were coordinated by the Harris County (Texas) Medical Examiner and County Coroner. Search and rescue efforts were delayed until the fire and heat subsided and all danger of further explosions had passed. These operations were difficult because of the extensive devastation in the HCC and the danger of structural collapse on the search and rescue team. The Phillips 66 Company requested, and the FAA approved and implemented, a 1-mile no-fly zone around the plant to prevent engine vibration and/or helicopter rotor downwash from dislodging any of the wreckage. The U.S. Coast Guard and City of Houston fire boats evacuated to safety over 100 trapped people across the Houston Ship Channel. OSHA preserved evidence for evaluation regarding the cause of the catastrophe.
Phillips employees fatally wounded, listed by name, age, city of residence within Texas, and official date of death (following recovery and identification of remains or eventual death from injuries):
Fish Engineering employees fatally wounded and official dates of death:
OSHA's major findings included: Lack of process hazard analysis; inadequate standard operating procedures (SOPs); non-fail-safe block valve; inadequate maintenance permitting system; inadequate lockout/tagout procedures; lack of combustible gas detection and alarm system; presence of ignition sources; inadequate ventilation systems for nearby buildings; fire protection system not maintained in an adequate state of readiness. Additional factors found by OSHA included: Proximity of high-occupancy structures (control rooms) to hazardous operations; inadequate separation between buildings; crowded process equipment; insufficient separation between the reactors and the control room for emergency shutdown procedures.
Quoting from a key OSHA document:
"At the conclusion of the investigation (April 19, 1990), OSHA issued 566 willful and 9 serious violations with a combined total proposed penalty of $5,666,200 to Phillips 66 Company and 181 willful and 12 serious violations with a combined total proposed penalty of $729,600 to Fish Engineering and Construction, Inc., a maintenance contractor on the site."
As a result of a settlement between OSHA and Phillips 66 Company, OSHA agreed to delete the willful characterization of the citations and Phillips 66 agreed to pay a $4 million fine and to institute process safety management procedures at HCC and the company's sister facilities at Sweeny, Texas; Borger, Texas; and Woods Cross, Utah.
Today, the facility continues to manufacture high-density polyethylene (HDPE), as well as K-Resin SBC. This complex employs 750 workers for the production of specialty chemicals, including 150 operations and maintenance personnel.