Author(s): Alan Earls. Published on March 1, 2010.

Imperial Sugar meeting
Ron Allen, the new senior director for environmental health, safety, and quality at Imperial Sugar Company and a member of NFPA, meets with managers at the Gramercy, Louisiana refinery. (Photo: Ed Lallo)

Refining The Process
As part of its goal to create a new, state-of-the-art refinery following a catastrophic explosion and fire in 2008, Imperial Sugar turned to Ron Allen to help it devise and implement safety features in all of its facilities. As Allen will tell you, installing the right equipment is easy. The tough part is making sure workers put safety first, day after day.

NFPA Journal®,March/April 2010

By Alan R. Earls

To make sure his co-workers at Imperial Sugar get the message on dust safety, says Ron Allen, it helps to think like a dance instructor.

Imperial safety head to speak at dust explosion event
Ron Allen, the new head of safety at Imperial Sugar, will be among the presenters at an upcoming three-day symposium on dust explosions.

Makeover challenge
Bringing new safety features to a refinery even older than Port Wentworth.

NFPA codes at the center of the rebuild
NFPA codes were integral to the rebuilding process at Imperial Sugar’s Port Wentworth, Georgia.

Our hazards, ourselves
Why you need to know about process hazard analysis, and why you need to know how to use it.

 Dust: When A Nuisance Becomes Deadly (Nov/Dec 2008)
 U.S. Chemical Safety and Hazard Investigation Board: Sugar Dust Explosion and Fire Invesigation Report (PDF, 2.9MB)

"Everyone thinks they know how to dance, but to dance well takes practice," says Allen, the new senior director for environmental health, safety, and quality at Imperial Sugar Company and a member of NFPA. "I’ve had to make sure that everyone learns the lessons and keeps practicing."

Imperial Sugar has had to learn some hard lessons. On February 7, 2008, at about 7:15 p.m., something—possibly an overheated bearing—ignited sugar dust in Imperial’s refinery in Port Wentworth, Georgia, causing a series of powerful dust-fueled explosions along the length of the facility’s conveyor. The blasts and subsequent fires destroyed much of the facility; the loss was estimated at $275 million. Fourteen employees were killed and dozens injured. In its investigation report, released late last year, the U.S. Chemical Safety and Hazard Investigation Board (CSB) cited poor maintenance, housekeeping, and equipment design as factors in the catastrophe and described the event as "entirely preventable." The U.S. Occupational Safety and Health Administration (OSHA) said it found scores of "willful" and "particularly flagrant" safety violations, which prompted OSHA to issue $8.7 million in fines against Imperial Sugar, a figure that represents the third-largest fine in the agency’s history.  Imperial Sugar continues to face numerous lawsuits related to the incident.

Imperial soon announced plans to rebuild and promised to do things differently than before. The company’s CEO, John Sheptor, said publicly that Imperial intended "to build the safest and most modern packaging facility possible." Against a backdrop of investigations and public hearings related to the explosion and fire, Imperial went ahead with its reconstruction plan, hiring leading dust consultants, architects, suppliers of safety equipment, and contractors to execute a project with a budget of $225 million.

The project was already underway when Allen arrived in March 2009. Along with monitoring the myriad details that went into creating a new facility, as well as creating the maintenance and housekeeping procedures necessary to keep it safe, Allen gave himself one large, overarching task: to remain focused on what he calls the "end game" of changing the safety culture at Imperial Sugar.

Change doesn’t come easily, however, even in the wake of calamity, and Allen sometimes wondered what he’d gotten himself into with the Imperial job. He admits to moments of "cold feet" in his new role, even though he’d tackled safety issues in previous jobs, most recently at Eaton Corp., an Ohio-based power management company. "This time I felt I was at the base of a mountain with a climb that seemed to be almost vertical," he says. "Even after the calamity, I was frequently amazed to find that there was a sense of complacency among some employees—they seemed to think it couldn’t happen again."

Among safety professionals, changing the culture of an organization is commonly recognized as one of the biggest challenges for a safety program, says Guy Colonna, NFPA division manager for Industrial and Chemical Engineering. "The plant reconstruction, consultants, and state-of-the art safety equipment represent the better-defined aspect of Imperial’s return to full productivity," Colonna says. "The less quantifiable, but more challenging, hurdle in this process involves the human element."

Change agent
According to the CSB report, complacency as much as anything else was at the root of the 2008 disaster. Ranked at the time of the accident as the second-largest sugar refining and packaging operation in the United States, the Port Wentworth facility was constructed in 1917 and was acquired by Imperial in 1997. There had been fires at the facility over the years, but they’d been relatively small and quickly forgotten. Managers at Port Wentworth had grown accustomed to living with dust and granulated sugar waste and, according to the CSB report, could have been lulled into a false sense of security by the fact that nothing very serious had ever happened.

Even the fact of recent dust explosions around the country, including a large explosion and fire at a Domino Sugar facility in Baltimore in November 2007 that injured several workers and caused significant damage, seemed unable to shake the Imperial managers’ conviction that it couldn’t happen at Port Wentworth. "They knew sugar dust could be dangerous," says John Vorderbrueggen, CSB investigation supervisor, "but unfortunately their years of experience and the fact that they had only had small fires before was telling them that they didn’t really have an explosion hazard."

In 2003, CSB investigated three dust explosions involving different types of dusts, different processes, and different industries, incidents that formed the basis for the CSB combustible dust study that was completed in 2006. CSB intended the study to call attention to the hazards of combustible dust fires and explosions, including the dangers present in Imperial’s operations, but the company apparently missed the warning.

Imperial wasn’t alone, says Vorderbrueggen, adding that most of the sugar-refining industry was "in denial" about the danger posed by combustible dust. For example, he says, it wasn’t until after the Imperial Sugar disaster that Domino beefed up its own combustible dust safety efforts, which included hiring a full-time manager to focus on dust hazards.

In his report on the Port Wentworth disaster, Vorderbrueggen concluded that a belt conveyor that ran beneath the sugar silos and spanned much of the rest of the facility was the immediate cause of the Imperial Sugar explosion. The conveyor was newly encased in a stainless-steel shroud to reduce potential contamination of the sugar, he says, but the shroud effectively ensured the presence of explosive concentrations of combustible sugar dust inside the enclosure.

Regardless of what triggered it, the resulting blast was enormous; security cameras two miles away captured the huge fire ball climbing into the night sky. The shock of the explosion loosened and lifted more of the accumulated sugar dust that saturated nearby areas, causing an almost instantaneous cascade of fires and explosions powerful enough to crack concrete floors and blow out brick walls. The blasts and fires damaged or destroyed the packing buildings, silos, palletizer building, the refinery area, and the bulk sugar loading area.

As part of its master plan for change and reconstruction, Imperial set its sights on recruiting Allen, who spent five years as senior manager for environmental health and safety at Eaton, where he had helped dramatically improve the company’s safety record. His approach to improvement at Eaton was built on developing a common management system for all safety issues, and it yielded remarkable results: a 90 percent decrease in reportable injuries under the OSHA record-keeping system, which tallies individuals hurt seriously enough to require medical attention. "My experience at Eaton had taught me that climbing the mountain is more satisfying than being at the top," says Allen, 60, "so I was looking for another challenge."

At Imperial, Allen’s responsibilities combine operational safety with the quality and safety of the food product. He’s based at Imperial’s headquarters in Sugarland, Texas, but spends most of his time at the company’s refineries in Port Wentworth, with 340 employees—the rebuilt refinery reopened late last year—and Gramercy, Louisiana, with 273 employees. His primary task, in a nutshell, is to help Imperial execute a safety about-face after decades of largely ignoring the biggest threats. "We wanted a change agent," says John Clements, Imperial’s vice-president for manufacturing. "That’s why we hired Ron Allen."

Separate, isolate, suppress
The goal of the Imperial rebuild at Port Wentworth wasn’t merely to replace the facility that had been destroyed; it was to replace it with one that was state-of-the-art from a safety standpoint. The project included a number of safety objectives, including meeting or exceeding code or regulatory requirements set by the state, county, OSHA, the CSB, and NFPA (see the sidebar "NFPA codes at the center").

Imperial didn’t have that expertise in-house, Allen says, so it went out and found it. For example, Chilworth Technology, Inc., a consulting company, was hired to help with a process hazard assessment (see the sidebar "Our hazards, ourselves") and provide design input. Other key players included Fike Corporation, The Dennis Group, LLC, Thomas & Hutton Engineering Co., VEi Global, Inc., and Fluor Corp. As Imperial cultivated those partnerships, Allen says, they helped him and his team better understand the risks associated with combustible dust and how to reduce risks to the lowest possible level.

Allen says the result was a system and functional design for the new plant that emphasized the concepts of separation, isolation, and suppression. Allen explains that dust presents special challenges because, in addition to the traditional fire triangle of fuel, oxygen, and ignition, dust hazards also involve dust particles suspended in the air and containment of those particles. "Oxygen will always be present, so we have had to work to mitigate the other sides of that pentagon," says Allen.

For Port Wentworth, separation meant configuring the facility to prevent the kind of interlocking sequence of events that had produced the 2008 disaster, including relocation of the huge sugar storage silos, an increased use of stand-alone buildings, and inclusion of fire walls within buildings.

The principle of isolation took the separation concept to a more tactical level, ensuring that separate systems were isolated from each other as much as possible and employing technologies such as rotary lock valves and dense-phase conveying of the sugar to reduce explosion potentials and to segment the process to prevent small incidents from propagating into catastrophic failures.

Finally, separation and isolation would be backstopped by suppression. This included canister-type chemical suppressant systems in specific parts of the process, ample water mains for traditional firefighting, and explosion vents for rooms, buildings, tanks, silos, and elevators to dissipate energy should an explosion occur.

Early in the planning process for the new facility, designers subjected each of the refinery’s dry processes to a separate process hazard analysis, a thorough, step-by-step effort to identify any possible fire or explosion risk. The effort included trained facilitators from Fluor and included consultants and engineers from key partners such as Chilworth Technology. It also included Imperial’s internal managers, as well as shop floor sugar processing equipment operators and plant maintenance technicians. According to Allen, the analysis provided a coherent picture of the nature and scale of risk for each area that was evaluated and was fundamental to developing plant designs and operational practices. "We made sure we engaged the people closest to the action so that we wouldn’t overlook the obvious, and I think it’s fair to say that the output wouldn’t have been as robust without this broad engagement," says Allen. "From there, we determined which risks were acceptable and which ones needed to be addressed in an action plan."

The new Port Wentworth facility is designed to minimize the accumulation of dust. One of the major changes in production was the introduction of the "dense phase" concept to the sugar conveyance process. Previously, sugar was moved through ducts where most of the space was air; sometimes compressed air was added to help move the sugar along. That not only allowed room for sugar dust to form, but it also supplied plenty of oxygen. Allen says the project engineers came up with the new process, where more tightly packed slugs of sugar are moved slowly in a way that minimizes dust formation and allows less room for air, which can significantly reduce the possibility of an explosion.

Flat surfaces have been kept to a minimum in the rebuilt plant. Similarly, a new "walk-on" ceiling, a sort of mezzanine level in production areas, separates much of the utility and process piping, ducting, and lighting from the actual process areas, with the aim of reducing or eliminating areas where dust fuel can accumulate.

Additional steps have been taken to monitor ignition sources and to minimize the impact of a fire or explosion. Potential ignition sources are controlled by having sensors on equipment that will detect heat and by using higher-classification electrical systems, including explosion-proof electric motors. The separation concept includes keeping people away from areas of higher risk, such as fuel sources. A series of interlocks throughout the process areas is designed so that, in the event of a fire or explosion, other systems will shut down safely. There is widespread protection against static electricity, including a grounding system and conductive coatings on the floor designed to discharge any buildup of electrical charge in materials on or near the floor.

Since dust explosions are composed of a complex set of conditions, NFPA’s Colonna cautions that any program designed to control those conditions must rely on more than a single protective measure. "Those measures need to start with the process hazard analysis, and they need to include all the key elements of engineering controls, both passive and active," Colonna says.

Culture change
While the concepts of separation, isolation, and suppression form the core of Imperial’s conspicuous changes in facility design and protection, Colonna says, the more elusive aspect of its overall program remains tied to the human element, the most fragile variable in determining the prospects for success since it relies on the attitude of the workers. That’s where Allen’s end game comes in: changing the fundamental culture at Imperial so that safety standards are not just tolerated, but genuinely valued.

It starts by establishing high safety standards, Allen says. "We consider compliance with all the relevant codes to be a minimum, and then we build our procedures and policies on that foundation to further mitigate risk." The next step is making sure managers demonstrate that they’re serious about adhering to those standards.

To stress the importance of house keeping—primarily the removal and control of spilled sugar, as well as general maintenance of both process and safety systems—plant managers or senior managers at the Gramercy and Port Wentworth facilities have, on a number of occasions, shut down operations because of housekeeping concerns, Allen says. "By setting this example, we soon found that departmental managers and then front-line supervisors were shutting down departments or pieces of equipment when housekeeping improvements were needed," he says. Eventually, even individual operators began shutting down their equipment when they determined that housekeeping improvements were needed. "Had the examples not been set further up the line, that culture change would not have occurred at all levels," says Allen.

Still, Allen says the work is not complete. "People in my field like to talk about culture change, but it is always evolutionary and ongoing, a continuing effort to get individuals to lock in the values associated with safety," he says. "Change is always difficult for people, and it has been hard for some to adopt our new, more conservative practices." While a few employees have been subject to disciplinary action for not following proper procedures, Allen stresses that most employees aren’t fighting the changes he’s trying to make. "Some people are just struggling to get their minds around them," he says.

To that end, Allen has introduced a computer-based safety training program consisting of modules targeted at different types of individuals, including plant workers and contractors who work on site. A module still under development focuses on preventive maintenance. "That one includes details like how to ensure a dust collector is properly grounded, how to maintain a screw conveyor to reduce friction, and how to measure the temperature of a bearing," says Allen.

One of his key goals is to create an environment of employee involvement and teamwork for addressing safety issues, Allen says, adding that Imperial has hired a number of new managers with experience at operations with superior safety programs. Allen declines to say whether any managers were let go from the plant in the aftermath of the 2008 explosion, but he says in general turnover at Port Wentworth has been low. He notes, however, that "we made sure we had the right team of managers on board to reduce risk."

Allen says that the new managers can help employees "learn to see" more quickly than they might on their own and that existing employees, in turn, can help the new managers by acquainting them with the nuances of sugar production. Together, managers and employees work toward a goal of zero safety-related incidents.

Allen says he and his team aggressively identify and investigate "near misses"—in one instance, a defective and potentially dangerous screw conveyor—to help emphasize that the company is serious about safety and won’t wait for an accident to occur in order to make needed changes.

Colonna cautions that change itself needs to be managed and monitored, and that the entire process needs to be re-evaluated whenever a change or upgrade is instituted. "For change to mean anything, it’s essential that change management is incorporated into the program," Colonna says. "That ensures that whenever materials, processes, equipment, or personnel change, the process hazard analysis resets, reexamines the overall hazards and control measures in place, and makes corrections as needed."

Similarly, Allen says he’s trying to ensure consistency between the Port Wentworth operation and the company’s other major facility in Gramercy, Louisiana. That means that as one location develops a set of findings or has a new initiative, that insight or direction is shared with the sister operation. The policy includes everything from major engineering efforts to day-to-day operations. "If we have any kind of incident at one facility, we immediately alert people at the other," Allen explains.

In the case of the screw conveyor, for example, workers at the Gramercy plant found the potential defect. "My boss, the vice-president of manufacturing, and our engineers flew to the plant," says Allen, where the team spent the weekend disassembling conveyors, measuring gaps between components, and assessing temperature buildup. Everything learned at Gramercy was immediately conveyed to Port Wentworth.

For now, Allen says it’s just good to have the facility operating again. "We’re pleased to be back in business, making sugar," he says. "From here on, we are in a continuous improvement mode."

Vorderbrueggen is satisfied, too—at least for now. "I have visited both Port Wentworth and Gramercy, and it seems like Imperial Sugar has really gotten religion when it comes to safety," he says. "They’ve gone to the maximum when it comes to managing, controlling, and minimizing dust risks."

Still, as Vorderbrueggen and Allen readily point out, dust is hard to control, and people can unlearn vital safety lessons, especially as the memory of the catastrophe begins to fade. Whether Imperial can deliver on its safety-first promises in the long term remains to be seen. More immediately, Allen says he isn’t ready to rest on his laurels. He sees this as a critical moment in the way the food industry deals with the combustible dust threat, and he says he wants to be a part of it. "We think an opportunity has been created for us to make a difference," he says. "We hope we can."

Alan R. Earls writes on technical and safety topics and is based in Franklin, Massachusetts.


Imperial safety head to speak at dust explosion event

Ron Allen, the new head of safety at Imperial Sugar, will be among the presenters at an upcoming three-day symposium on dust explosions.

The symposium, "Dust Explosion Hazard Recognition and Control: New Strategies," co-sponsored by NFPA and the Fire Protection Research Foundation, will be held October 19 to 21, 2010, in Kansas City, Missouri. Topics will include dust regulations and enforcement, research, best practices, and other topics, with presenters from industry, insurers, regulatory agencies, and standards-development organizations, among others.

Allen’s presentation will be "A Comprehensive Approach Toward Preventing Combustible Dust Explosions."

Find out more information or register for the symposium.


Makeover challenge
Bringing new safety features to a refinery even older than Port Wentworth

In the wake of the Port Wentworth, Georgia, catastrophe, Ron Allen, the new senior director for environmental health, safety, and quality at Imperial Sugar, says the company also decided to implement major upgrades at its plant in Gramercy, Louisiana (pictured), a facility that is even older than the one in Georgia.

"On the one hand, we were rebuilding Port Wentworth, so it was a blank sheet of paper, and we could raise the bar [for safety and operational efficiency,]" says Allen. By contrast, the Gramercy plant, built in 1895, represented a huge retrofitting challenge. "It was a plant that had undergone multiple expansions and had very old construction that challenged our engineers to come up with designs that met the appropriate NFPA code. In many cases, there wasn’t as much room to add new safety features."

As a consequence, the Gramercy plant has had to follow the lead of Port Wentworth, Allen says—but only to a point. "There was no way to implement many of the systems we have at Port Wentworth to ensure good housekeeping, so at Gramercy we have had to permanently assign 50 percent more people just to clean up sugar spills."

NFPA’s Guy Colonna adds that it’s critically important that workers are trained in effective housekeeping techniques and that housekeeping measures are done properly and consistently. "As some incidents have shown, housekeeping, when done improperly, can actually cause more problems," Colonna says.

The safety culture at the Gramercy refinery also posed a distinct challenge for Allen and his new team. "I definitely heard some feedback indicating that some people felt the Port Wentworth explosion wasn’t their problem and that they didn’t really need all the safety changes we were bringing in," he says.

In the longer term, Imperial Sugar says it plans to build a new refinery in Gramercy next door to the existing refinery. The project will be funded through a three-way joint venture among Imperial, Cargill, Inc., and Sugar Growers and Refiners, Inc. Once completed, according to the company, the refinery will produce 1 million tons (907,185 metric tons) of sugar products a year, making it the largest sugar refinery in the United States. The new facility will replace much of the existing one, says Allen, who insists that the new safety measures developed at Gramercy and Port Wentworth will be integral to the new facility.


NFPA codes at the center of the rebuild

NFPA codes were integral to the rebuilding process at Imperial Sugar’s Port Wentworth, Georgia, refinery and in retrofitting its refinery in Gramercy, Louisiana, according to Ron Allen, the company’s new senior director for environmental health, safety, and quality.

  • NFPA 10, Portable Fire Extinguishers
  • NFPA 13, Automatic Sprinkler Systems Handbook
    Provided guidance for design and installation of sprinkler systems.
  • NFPA 61, Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities
    Provided primary guidance on how to design a facility to reduce combustible dust hazards.
  • NFPA 68, Explosion Protection by Deflagration Venting
    Provided guidance on sizing, design, and maintaining explosion vents and rupture disks, and their "safe" discharge points.
  • NFPA 69, Explosion Prevention Systems
    Provided guidance for the design and application of chemical isolation and suppression systems. Also guided Imperial on spark detection and extinguishing systems and on deflagration pressure containment and combustible concentration reduction, and provided guidance for maintaining these systems.
  • NFPA 70®, National Electrical Code®
  • NFPA 72®, National Fire Alarm and Signaling Code®
  • NFPA 101®, Life Safety Code®
    Provided guidance on all life safety issues, including emergency lighting, alarms, and means of egress.
  • NFPA 499, Classification of Combustible Dusts and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas
    Provided guidance for designing electrical systems and components to ensure the facility has explosion-proof and dust-tight equipment where there is risk of dust fires or explosions.
  • NFPA 505, Fire Safety Standard for Powered Industrial Trucks Including Type Designations, Areas of Use, Conversions, Maintenance, and Operations
    Provided guidance regarding the types of industrial trucks that can be safely used in environments where combustible dust may be present.
  • NFPA 654, Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids
    This was referenced only indirectly. Imperial’s Ron Allen says NFPA 654 can provide additional guidance and depth while designers rely primarily on NFPA 61. There are instances where NFPA 61 defers to NFPA 654, such as on the topic of pneumatic conveying.
  • NFPA 780, Standard for the Installation of Lightning Protection Systems


Our hazards, ourselves
Why you need to know about process hazard analysis, and why you need to know how to use it

With a process hazard assessment, or PHA, one size does not fit all.

The purpose of a PHA is to determine the hazard in an industrial facility or in a single piece of equipment. The hazard could be dust, a volatile gas, or even a compressed inert gas. "It could be anything," says Vahid Ebadat, CEO of Chilworth Global, a process safety consulting firm. It’s the nature of the potential hazard that helps drive the inquiry.

Three main types of PHAs have evolved. When a machine or facility is in the planning or development stage, you can perform an initial hazard analysis, also known as a desktop hazard analysis, the idea being to identify and address issues prior to construction, says Ebadat. When a facility actually exists, there are two further choices. One is a checklist analysis, usually based on standards, codes, or regulations; the reference document or documents are extrapolated onto the facility, and any applicable issues become part of a checklist that must be addressed. Finally, there is the "what-if" analysis, which could start with the same checklist items but would attempt to probe deeper, considering what could happen in worst-case situations, or in scenarios not otherwise obvious. Ebadat says these analyses can be performed with varying degrees of thoroughness, depending on time and resources.

NFPA 654, Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids, is one of the codes that includes a PHA requirement. NFPA 654, in turn, references Guidelines for Hazard Evaluation Procedures, with Worked Examples, 2nd Edition, published by the Center for Chemical Process Safety (ISBN: 0-8169-0491-X), which is regarded as the bible of PHA by many consultants and safety practitioners.

John Cholin, principal of J.M. Cholin Consultants, Inc., specializes in PHAs, especially in the dust hazard field. To get a deeper understanding of potential dust hazards, he says, he starts his what-if analysis with an Excel spreadsheet and a process-flow diagram from the client, then assigns a location number to every item and every space associated with that process. That information is mapped against all potential classes of hazards, such as flammable and electrical. Risk must be assessed for each of those items and hazards, as well as potential combinations of items and hazards.

The result is a document "about what to do to manage the hazards, and an indication of what has been managed and how," says Cholin. "In many processes it’s like peeling back the layers of an onion, because vessels can be interconnected by ductwork or linked through different parts of a building where there could be fugitive dust leaks or accumulations. It can be a nauseatingly detailed process, but that’s the only way to have a good prospect of ensuring safety."

Guy Colonna, NFPA division manager and staff to the NFPA 654 committee, says the hazard analysis process is crucial for the requirements of NFPA 654 because it allows facility operators a chance to determine if they have a dust hazard, to characterize the severity of that hazard, and to begin to establish necessary corrective or control measures. "The committee has introduced that requirement in previous editions of NFPA 654, and with the revision being prepared for adoption by the membership in June, the requirements would strengthen and continue to highlight the importance of performing a hazard assessment," he says.

- Alan Earls