At a Senate hearing recently, John Bresland, chairman and CEO of the U.S. Chemical Safety Board (CSB), called on the Occupational Safety and Health Administration to act on a November 2006 CSB recommendation to adopt a comprehensive standard regulating combustible dust in the workplace.
Speaking before the Subcommittee on Employment and Workplace Safety, Senate Committee on Health, Education, Labor, and Pensions, chairman Bresland said this year's tragedy which killed 13 workers at Imperial Sugar's Georgia refinery – caused when sugar dust was ignited and exploded - demonstrates the need for a new OSHA standard that would cover a range of industries exposed to this hazard. Such industries include food, chemicals, plastics, automotive parts, pharmaceuticals, electrical power (where generated by coal) and others.
Chairman Bresland told the subcommittee, chaired by Sen. Patty Murray of Washington, "After witnessing the terrible human and physical toll from the Imperial explosion, I believe the urgency of a new combustible dust standard is greater than ever. A new standard, combined with enforcement and education, will save workers' lives."
Bresland displayed a number of photographs, obtained during the CSB's ongoing investigation of the accident at Imperial Sugar, showing substantial amounts of sugar dust on elevated surfaces and floors at the company's refinery in Port Wentworth, Ga. These photographs were taken in 2006, Bresland said, adding that testimony to the CSB indicates large amounts of sugar dust remained in the facility until the accident on February 7, 2008.
The photographs were posted on ftp://ftp.csb.gov/SenateDust and also included in Bresland's written testimony.
Bresland said, "We obtained documents indicating that certain parts of Imperial's milling process were releasing tens of thousands of pounds of sugar per month into the work area. Based on our evidence, Imperial did not have a written dust control program or a program for using safe dust removal methods. And the company lacked a formal training program to educate its workers about combustible dust hazards." Imperial operators interviewed by the CSB had minimal knowledge of those hazards.
The chairman noted the CSB's 2006 Combustible Dust Study identified 281 dust fires and explosions in the U.S. between 1980 and 2005, killing 119 and injuring 718 workers. These included major dust explosion accidents in North Carolina, Kentucky and Indiana in 2003, killing a total of 14 workers.
Bresland said that since the study was released, media reports have indicated there have been approximately 82 additional dust fires and explosions. In the report, the board also recommended improved training of OSHA inspectors to recognize dust hazards, better communication of dust hazards to workers through material safety data sheets (MSDSs), and instituting a national emphasis program to better enforce existing standards – something which OSHA has now begun and for which Bresland commended the agency.
He noted that good engineering and safety practices to prevent dust explosions have existed for decades, and that current good practices are contained in numerous National Fire Protection Association (NFPA) standards, some of which have been adopted by state and local governments in their fire codes.
Bresland said, "OSHA has recognized the importance of NFPA's dust standards and they are referenced numerous times in the National Emphasis Program that OSHA began last year and reissued earlier this year." However, he added, without a comprehensive OSHA standard for combustible dust, it is difficult for businesses to know which specific NFPA provisions or other requirements they may be subject to.
"A comprehensive OSHA dust standard is necessary to get businesses, government inspectors, and insurers to identify dust hazards and take appropriate actions to control them. Existing standards do not clearly identify what kinds of dust are hazardous and only address limited aspects of how to control those hazards," he said. "Instead of the present patchwork of miscellaneous federal, state, and local requirements, the Chemical Safety Board has recommended that OSHA develop a single, comprehensive, uniform standard – based on the sound, consensus-based technical principles and practices that are embodied in NFPA standards. Ambiguities in the NFPA standards need to be resolved in clear, enforceable regulations developed by a thorough, public rulemaking process."
In his testimony, Bresland updated the subcommittee on CSB findings to date in its investigation of the explosion at Imperial Sugar. He said multiple witnesses have told CSB investigators that there were large accumulations of sugar at many locations in the packaging plant. Near the powder mills, powdered sugar accumulated on the floor to a "mid-leg" height. Airborne sugar in this room made it difficult for workers to see each other.
On elevated surfaces, witnesses described dust buildups of around an inch. National Fire Protection Association literature indicates accumulations of just 1/32 of an inch of dust covering just 5 percent of the available surface area, should be considered hazardous. An initial explosion in a plant can shake loose accumulations of dust elsewhere, suspending the particles which are then ignited, causing a powerful, secondary explosion.
The CSB investigation has determined that a 2007 Imperial Sugar incident investigation report of a worker's skin injury stated that powdered sugar was piled up below the mill approximately 18 inches high.
Furthermore, much of the electrical equipment in the sugar packaging plant was not dust-tight and therefore was not appropriate for use in plant areas where combustible dust could form an explosive atmosphere. The CSB has also found that the half-century old packaging building on the south side of the silos had equipment that did not incorporate effective design features to prevent the spread and accumulation of dust, he said.
Bresland said, "I believe these findings are further evidence of the need for a comprehensive regulatory standard for dust. It is time for all the interested parties - industry, labor, and government - to move forward toward a standard that will protect workers, businesses, and communities well into the future," he said.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.
The board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. Visit our website, www.csb.gov.
