WEST LAFAYETTE, IND. — There were seven reported grain dust explosions at U.S. food and agricultural facilities in 2017, two more than in 2016 but still below the 10-year average of 9.3 explosions per year, according to an annual report issued on March 8 by Purdue University’s Department of Agricultural and Biological Engineering.
The explosions in 2017 resulted in five fatalities and 12 injuries. Incidents were reported at one pet food plant, one grain mill and five grain elevators. There were three fatalities in 2016.
Kingsly Ambrose, assistant professor of agricultural and biological engineering and lead author of the report, said preventive measures can be taken to avoid dust explosions.
“Even with a 40% increase in the volume of grains handled and processed since the OSHA grain-handling standard was promulgated in 1988, the number of incidents has steadily declined over the past 10 years,” Mr. Ambrose said. “Keeping the facility clean, training employees and contract workers, keeping equipment in good working condition by preventive maintenance and the use of dust explosion suppression systems and venting systems are good prevention practices.”
Indiana, Iowa, Nebraska, Oregon and Minnesota each reported one explosion last year, and two happened in Wisconsin. All dust explosion fatalities in 2017 happened in Wisconsin during a single incident, which also accounted for 11 injuries. The other injury was reported in Oregon.
On May 31, an explosion at a Didion Milling Inc. facility in Cambria, Wis., claimed the lives of 5 workers and injured 11 others. As part of its findings, OSHA determined that the explosion likely resulted from Didion’s failures to correct the leakage and accumulation of highly combustible grain dust throughout the facility and to properly maintain equipment to control ignition sources. OSHA cited Didion with 14 willful citations, including 8 willful per-instance egregious citations. Didion also was cited with five serious citations, most involving fire and explosion hazards. The company has been placed in OSHA’s Severe Violator Enforcement Program. Didion Milling is contesting some of the citations issued by OSHA, which fined the company $1.8 million.
In two cases, the cause was reported as an overheated bearing and electric spark. The remaining five cases had unknown ignition sources, which Mr. Ambrose said is often the case due to the explosion destroying evidence that could confirm the source.
Mr. Ambrose said dust is generated when grain is moved, which is why most 2017 explosions occurred in the latter half of the year when grain is more likely to be handled.
“Though explosion suppression systems provide some protection, we must keep in mind that grain dust explosions can only be controlled through preventive measures,” he said.