An employee at a soap manufacturing plant died in a flash fire outside the facility's hydrogenation building. Responding personnel encountered a fire at the base of the plant's hydrogen storage towers, and they found the victim, who was burned over 90 percent of his body, some 50 feet away.

Officials determined that a pipe connection failed and that hydrogen, pressurized at 1,800 psi, ignited when it was released into the atmosphere, killing the plant operator.

According to reports, the pipe connection failure stemmed from pressures higher than design tolerance, which in turn were the result of over tightening that occurred during routine maintenance replacement. The new bolts were stronger than those they replaced, and the threads of the nuts had been partially corroded with age.

This combination of factors led to the failure and the flash fire. The facility's automatic detection system and wet pipe sprinkler system were not factors in the fire. When the plant's emergency response team arrived, it directed two monitor nozzles on the fire scene and the hydrogen towers. Responding fire companies added a third nozzle stream when they arrived at 11:50 am. The combined forces knocked down the fire in just over one-half hour.

Damage was estimated at $250,000.

Incident Date
Aug 01, 1991
Damage and Injuries
When Incident Discovered
Lessons Learned

Routine maintenance activities on pressurized hydrogen systems should be conducted per written design specifications. The procedures should provide detailed oversight regarding bolt, nut and fitting replacements or repairs. A formal review process should be required to ensure that the maintenance was performed according to the written specifications, and that the hydrogen system will continue to function as designed until the next scheduled maintenance activity.