Industry should improve safety standards covering hazardous waste processing, handling and storage facilities, says a case study from the U.S. Chemical Safety Board (CSB), released following its investigation of the 2009 explosion and fire at the Veolia ES Technical Solutions LLC facility in West Carrollton, Ohio. The CSB also recommended that fire protection codes be revised to require companies to determine safe distances between occupied buildings and potentially hazardous operating areas.

The accident occurred on May 4, 2009, when flammable vapor was released from a waste recycling process, ignited and violently exploded. The blast seriously injured two workers and damaged 20 nearby residences and five businesses. CSB investigators found that the north wall of the lab and operations building, where the victims were injured, was less than 30' from the waste recycling processing area where the flammable vapor was released.

CSB Chairman Rafael Moure-Eraso said, “This accident should not have happened. Our report notes that OSHA cited the company for inadequate attention to process safety management practices in the handling of flammable liquids. But in case of an accident, I believe it is absolutely critical that buildings at chemical facilities be sited safe distances from process equipment to maximize the safety of workers. We are making recommendations that would help ensure that operating areas with occupied buildings such as control rooms be sufficiently separated from process areas containing flammable liquids and gases that have the potential to explode.”

The board issued a recommendation to the National Fire Protection Association (NFPA), Quincy, Mass., urging the codes-and-standards-making organization to require companies to perform engineering analyses to determine safe separation distances between buildings occupied by administrative and other personnel not essential to process operations, and buildings housing the potentially hazardous process equipment.

The board also revised a previous recommendation to the Environmental Technology Council, a hazardous waste industry trade group, to petition the NFPA to develop a standard specific to hazardous waste treatment, storage and disposal facilities. This would include guidance on reducing the likelihood of fires, explosions, and releases of hazardous waste.

Dr. Moure noted, “The Environmental Technology Council did not respond adequately to our 2007 recommendation, which we issued following an explosion and massive fire at the Environmental Quality hazardous waste facility in Apex, North Carolina, to work for more stringent standards in the hazardous waste industry. I strongly urge the industry to act now. These facilities, by their nature, contain wide varieties of flammable and toxic materials that can cause significant injury to workers and threaten the well being of nearby communities. Facility owners and operators need stricter technical requirements to improve the safety of life and property.”

The report notes that after a normal run of the tetrahydrafuran (THF) solvent recovery process at the Veolia facility, the unit operator began a routine shutdown. Completing the process required blowing nitrogen back through the circulation piping to clean it prior to closing valves. A sudden, loud vapor release occurred, and then the vapor drifted to the laboratory and operations building, where it found an ignition source.

In addition to issuing recommendations to NFPA and the hazardous waste industry, the Board also issued recommendations to Veolia, which is rebuilding the plant. The CSB called on the company to restrict occupancy in buildings in close proximity to the operating plant to personnel trained in the safe operation and orderly shutdown of the plant. The Board also called on the Center for Chemical Process Safety, a division of the American Institute of Chemical Engineers (AiChE), to revise control room siting guidelines to address the characteristics of all Class 1B flammable liquids.

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