Today's News

Final CSB report on Imperial Sugar disaster: inadequate equipment design, maintenance, and housekeeping led to fatal sugar dust explosions (9/25)

September 25, 2009
/ Print / Reprints /
ShareMore
/ Text Size+

In a final draft report released yesterday, CSB investigators said the February 7, 2008, explosion at the Imperial Sugar refinery in Port Wentworth, Georgia, resulted from 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 concluded.

The first explosion – known as a “primary event” – likely occurred inside a sugar conveyor located 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. The result was a powerful cascade of secondary dust explosions that fatally injured 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.

CSB Investigation Supervisor John Vorderbrueggen, P.E., who led the 19-month investigation, said, “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.”

The CSB report said 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 1960s that killed a total of ten workers.

But 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.

CSB Chairman John Bresland said, “Dust explosions can be among the deadliest of industrial hazards, particularly inside heavily occupied buildings. But these explosions are readily prevented through appropriate equipment design and maintenance and rigorous dust-cleaning programs. I call upon the sugar industry and other industries to be alert to this serious danger.”

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 final report proposed a series of safety recommendations for Board consideration. Imperial Sugar was urged to comply with National Fire Protection Association (NFPA) recommended practices for preventing dust fires and explosions, develop dust training and housekeeping programs, and improve its evacuation procedures. The report also called on industry groups AIB International and the American Bakers Association to develop combustible dust training and auditing materials. Imperial’s insurer, Zurich Services, and an insurance industry trade association should improve their insurance audit procedures for dust hazards and share their dust hazard training materials with clients, investigators concluded.

A 2006 CSB study identified 281 combustible dust fires and explosions between 1980 and 2005 that killed 119 workers and injured 718, and extensively damaged industrial facilities. The CSB recommended in November 2006 toOSHA to develop a comprehensive regulatory standard for combustible dust, based on existing NFPA consensus standards, and improve requirements for dust hazard communication to workers. In April 2009, OSHA announced it would commence the development of a standard.

Did you enjoy this article? Click here to subscribe to ISHN.

You must login or register in order to post a comment.

STAY CONNECTED

Facebook logo Twitter YouTubeLinkedIn

Multimedia

Videos

Image Galleries

ASSE's Safety 2013 Review

A photo gallery from the Las Vegas Convention Center, where ASSE’s annual professional development conference was held June 24 to 27. All photos courtesy of the American Society of Safety Engineers.

THE MAGAZINE

ISHN Magazine

ishn april 2014 issue cover

2014 April

In this month's issue of ISHN, check out features about safety in the oil and gas industry.

Table Of Contents Subscribe

THE ISHN STORE

M:\General Shared\__AEC Store Katie Z\AEC Store\Images\ISHN\safetyfourth.jpg
Safety Engineering, 4th Edition

A practical, solutions-driven reference, Safety Engineering, 4th edition, has been completely revised and updated to reflect many of today’s issues in safety.

More Products

For Distributors Only - January 2014

ISHN0114_FDO_cov.jpgFor Distributors Only is ISHN's niche brand standard-sized magazine supplement aimed at an audience of 2,000 U.S. distributors that sell safety products. Circulation only goes to distributors. CHECK OUT THEJANUAYR 2014 ISSUE OF FDO HERE

ishn infographics

2012 US workplace deathsCheck out ISHN's new Infographic page! Learn more about worker safety through these interactive images. CLICK HERE to view the page.