CSB: Port Wentworth explosion could have been prevented

A U.S. Chemical Safety Board report on Thursday said the fatal explosion at the Imperial Sugar Co. refinery in Port Wentworth, Ga., could have been prevented with better “housekeeping practices.”

CSB investigators said the Feb. 7, 2008, explosion was due to ongoing releases of sugar from inadequately designed and maintained dust collection equipment, conveyors, and sugar handling equipment.

Inadequate housekeeping practices allowed highly combustible sugar dust and granulated sugar to build up throughout the refinery’s packing buildings, CSB investigators said.

In Port Wentworth’s case, a first explosion likely occurred inside a sugar conveyor beneath two large sugar storage silos. The conveyor had recently been enclosed with steel panels creating a confined, unventilated space where sugar dust could accumulate to an explosive concentration. Sugar dust inside the enclosed conveyor was likely ignited by an overheated bearing, causing an explosion that traveled into the adjacent packing buildings, dislodging sugar dust accumulations and spilled sugar located on equipment, floors and other horizontal surfaces, CSB said.

The result was a powerful cascade of secondary dust explosions that killed 14 workers and injured 36 others, many with life-threatening burns. The refinery’s packing buildings were largely destroyed by the blasts and ensuing fires.

“Imperial’s management as well as the managers at the Port Wentworth refinery did not take effective actions over many years to control dust explosion hazards, even as smaller fires and explosions continued to occur at their plants and other sugar facilities around the country,” said CSB Investigation Supervisor John Vorderbrueggen, who led the 19-month investigation.

The CSB report said that the sugar industry was familiar with dust explosion hazards at least as far back as 1925. Internal correspondence dating from 1967 showed that Port Wentworth refinery managers were seriously concerned about the possibility of a sugar dust explosion that could “travel from one area to another, wrecking large sections of a plant.”

Precursor events included a 1998 explosion at Imperial’s plant in Sugar Land, Texas; an explosion at the Domino Sugar plant in Baltimore in November 2007; and two sugar dust explosions in the 1960’s that killed a total of ten workers.

However, CSB said Imperial management did not correct the underlying causes of the sugar dust problem at the Port Wentworth facility, where workers testified that spilled sugar was knee-deep in places on the floor, and sugar dust had coated equipment and other elevated surfaces.

The report said the company had not conducted evacuation drills for its employees and that the explosions and fires disabled most of the emergency lighting, making it difficult for workers to escape from the labyrinth of explosion-damaged buildings as the fires continued to spread.

The CSB is an independent federal agency charged with investigating industrial chemical accidents.

Earlier this month, Sugar Land, Texas-based Imperial Sugar (NASDAQ: IPSU) said all of its sugar packaging equipment is now on site and testing is underway on the first packaging lines. Imperial Sugar also said it has spent $149 million of the estimated $220 million in construction costs.

The refinery, which began shipping bulk sugar in late July, operated at about 25 percent of normal capacity in August and is now boosting production.

SOURCE: atlanta.bizjournals