Imperial Sugar Co. has closed the powdered sugar area of its Gramercy, La., refinery after federal inspectors said they found deadly hazards there, the Savannah (Ga.) Morning News reports.

OSHA said Monday that it discovered a buildup of combustible sugar dust in the area.

Investigators think such a buildup helped cause a Feb. 7 explosion and fire that killed 13 people and seriously burned 10 others at Imperial's Port Wentworth, Ga., refinery.

OSHA chief Edwin Foulke Jr. said a "serious accident that might result in death or severe physical harm" was likely at the Gramercy plant.

Foulke said the inspection was part of an OSHA program, begun in October, to focus on plants with a high risk of combustible dust explosions.

In the wake of the Port Wentworth disaster OSHA faces pressure to adopt tougher combustible dust standards. But Foulke stressed that the Gramercy plant was inspected under existing rules, which he has said can deal effectively with explosion risks.

He stopped short of saying the company will be cited or fined, but added that "clearly we identified some potential violations."

Imperial Sugar said it decided voluntarily to shut down operations in the powdered sugar area. The company said it is working with OSHA and "third-party experts to ensure that the area is safe for Imperial Sugar employees."

OSHA spokeswoman Sharon Worthy said the agency found that an "imminent danger" exists at the Louisiana plant, which means Imperial must devise and implement a plan to remove combustible dust and stop future buildup.

Meanwhile, OSHA’s investigation of the Port Wentworth fire is continuing and, according to recent statements by Foulke, might take months.