Mine Safety and Health Administration
Contact: Rodney Brown
Phone: (703) 235-1452
Released Monday, February 7, 2000
Federal Mine Safety Agency Issues Investigative Report on
Excessive pressure in several large tanks caused the July 5, 1999, explosion at the Kaiser Aluminum and Chemical Corp. plant in Gramercy, La., that injured 29 people, investigators from the Mine Safety and Health Administration concluded in a report issued today. Kaiser's failure to identify and correct hazardous conditions and unsafe practices contributed to the early morning explosion, investigators said.
"Kaiser's apparent failure to follow well-known safety rules and practices resulted in serious injury to workers at the Gramercy Plant," said J. Davitt McAteer, assistant secretary of labor for mine safety and health. "We are hopeful that these actions will be immediately addressed by Kaiser management so that we may avoid such tragic accidents in the future. And, most importantly, we hope others in the mining community will take note of the lessons learned here. "
Mine safety investigators found that an electrical power failure that occurred about 30 minutes prior to the explosion caused the Kaiser plant's electrically-powered process machinery to stop. Electrically-powered pumps, therefore, could no longer move the extremely hot liquid called "slurry" through the tanks in the process. The flow stopped and pressure built up in the tanks. Investigators also found that the plant's gas-fired boilers continued to deliver high pressure steam to vessels in the digestion area, increasing the pressure. The tanks then exploded with great force, resulting in the near total destruction of four tanks and the release of hot caustic material across the plant and into the surrounding community. Investigators found that the plant's system of relieving pressure in the tanks failed to prevent the build-up of pressure because relief valves had been impermissibly blocked.
The Mine Safety and Health Administration concluded:
Kaiser demonstrated disregard for the operating pressure limits established for the digestion area pressure vessels. Evidence shows that Kaiser knew of and condoned the practice of allowing the digestion process to operate even though pressure in one or more of the vessels exceeded the operating maximum.
Kaiser failed to follow the industry standard requiring functional pressure relief safety systems to be maintained for the digestion area pressure vessels. In fact, Kaiser knew of and condoned the practice of disabling these safety systems.
Kaiser failed to follow prudent engineering practices in failing to properly maintain the integral piping for the pressure relief safety system and the discharge pipe connecting the blow-off tank to the relief tank. Kaiser knew that slurry would periodically build up and harden inside the pipes but failed to ensure the pipes were inspected and free of obstruction.
Kaiser management failed to conduct required workplace examinations to identify conditions and practices that posed hazards to employees, and did not promptly correct the hazardous conditions and unsafe practices that were evident.
Kaiser failed to provide adequate safety and health training for employees nor did it provide proper training on safe operating procedures of their assigned tasks. Failure to provide training for employees on procedures to be followed during a power outage contributed significantly to the accident.
Kaiser failed to provide adequate protective clothing for employees who were exposed to hazardous chemicals.
The full report on the Kaiser explosion is available publicly through the contact listed on this News Release and through MSHA's Web site on the Internet at www.msha.gov.