Sugar refinery had prior dust explosion

February 17, 2008 2:49:13 PM PST
Dust that collected in a piece of safety equipment caused a small explosion at a sugar refinery weeks before the deadly blast that killed nine workers, a federal investigator said Sunday. Stephen Selk, investigations manager for the U.S. Chemical Safety Board, had few details about the previous explosion at the Imperial Sugar refinery in Port Wentworth. He could not say whether the earlier blast contributed to the massive explosion Feb. 7.

"It is far too early to reach conclusions about the relationship between that event and this one," Selk said.

No one was injured in the earlier explosion, Selk said. He did not know the exact date, but said it happened "weeks ago."

The Chemical Safety Board investigates industrial accidents for the federal government and makes safety recommendations to industry and trade groups as well as federal regulators.

It has just begun looking into the refinery blast after criminal investigators determined Friday the explosion was accidental - caused by clouds of tiny sugar dust particles that, when airborne in confined spaces, can ignite like gunpowder.

The refinery was equipped with a network of fans and ducts designed to prevent dust explosions by sucking particles out of the plant and transferring them to dust collectors on the roof, Selk said.

It was one of those rooftop dust bins that exploded weeks before the Feb. 7 blast, Selk said.

Selk said investigators haven't yet determined whether the dust extraction equipment was working in the part of the refinery where the larger explosion began - a basement area with conveyor belts used to move sugar from three giant storage silos to a nearby packaging area.

Evidence of sugar dust accumulation was found in the basement beneath the silos, investigator Phil Durham of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives said Friday.

Steve Behm, a spokesman for Imperial Sugar, said he did not know any details of the earlier dust explosion mentioned by Selk.

Investigators also have not determined what ignited the dust to cause the deadly explosion. The Chemical Safety Board is more concerned with why combustible dust was accumulating inside the refinery, Selk said.

"Finding the ignition source may be impossible," Selk said.

The explosion killed eight workers inside the plant, and a ninth worker died at an Augusta hospital. Fourteen people with severe burns remain in critical condition, and two workers are in serious condition.

The refinery is on a 160-acre site on the Savannah River just west of Savannah. About 12 percent of the plant's 872,000 square feet was destroyed by the explosion and fire.