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Statistics-based safety. Part 1: an analysis of the crushed stone injuries occurring during a 10-year span provides insight into improving safety.

Karra VK
Aggreg Manag 2006 Oct; 11(10):54-57
Making sure workers within the aggregates industry go home safely each day is the goal of aggregate companies throughout the United States. At the National Institute for Occupational Safety and Health (NIOSH) researchers are contributing to NIOSH's vision of safety and health through a fact-finding approach to reducing injuries/illnesses in various mineral sectors. Surveillance data from the Mine Safety and Health Administration (MSHA) has been the primary source for such analyses. It helps to focus research efforts on key machinery, workers, and their tasks. The crushed stone category referred to in this article is represented as crushed and broken stone in the MSHA database. In 2003, MSHA reports that 3,412 mines produced crushed stone, representing 23.7 percent of all mining operations. Crushed stone included limestone, granite, traprock, sandstone, slate, marble, and stone NEC (not elsewhere classified). There were 46,991 employees, comprising 22.2 percent of all mine operator employee hours. There were seven work-related fatalities and 1,443 non-fatal lost-time injuries resulting in 65,441 days lost from work. For further analysis of data, a 10-year period from 1994 to 2003 was selected. Average annual production during this 10-year period was used where feasible for determining the rate for the category under consideration. When production data was not available for a specific category, data for mean employee hours was used for determining the rate. Production-based rates were adjusted for 100 million tons production of crushed stone. Employee-hour based rates were adjusted for 10 million employee hours. Surface, mill, and underground work locations were considered. Fatal injuries were assessed by the number of fatalities during the 10-year period. In the case of non-fatal injuries, non-fatal days lost (NFDL) data was used for the assessment. Each of these injury categories was further analyzed in terms of the accident/illness/injury classification and worker activity at the time of injury. The later was analyzed for identification of top subcategories. In a recent report to the National Stone, Sand & Gravel Association, MSHA created a broader category - maintenance, repair, and construction (MRC) - comprising: machine maintenance and repair, non-powered hand tools, surface construction NEC (not elsewhere classified), welding and cutting elect/acetyl, powered hand tools, moving equipment (fans/pumps etc.), grinding bits/steel/welds, electrical maintenance/repair, operate hoist, working with chemicals, and working with noxious materials. This composite category was also assessed for fatal and non-fatal injuries and equipment responsible for those injuries. During the 10-year period, average annual production of crushed stone was 1.443 billion metric tons, representing 93.2 percent of all stone production, and the corresponding mean employee hours for all the three work locations were 104.446 million. For prevention of fatalities in crushed stone operations, primary focus should be on the surface and mill locations and on the analysis of powered haulage and machinery-related tasks. Worker activities associated with machinery maintenance, haulage trucks, front-end loaders, dozers, and other surface equipment should be a top priority in effective safety programs. In the MRC category, focus should be on tasks involving crane/derrick, crusher/breaker/mills, conveyors, and front-end loader/tractor-shovel. For non-fatalities prevention, the main focus should again be on the surface and mill locations and on the analysis of handling of material, slip/fall of person from an elevation, and tasks involving hand tools, powered haulage, and machinery. Key activities for improving safety should include machine maintenance/repair, handling supplies/material, getting on/off equipment/machines, non-powered hand tools, walking/running, and hand load/shoveling/mucking. In the MRC category, focus should be on tasks involving hand tools of all types, welding machine, all types of conveyors, crusher/breaker/mills, and front-end loader/tractor-shovel. Through emphasis on the above areas, proper training, and application of best work practices, the aggregates industry can continue to improve its safety record and to protect its employees.
Milling-industry; Stone-processing; Stone-products; Traumatic-injuries; Injuries; Injury-prevention; Mineral-processing; Surveillance-programs
Publication Date
Document Type
Journal Article; Trade; Lay Publication
Fiscal Year
Issue of Publication
NIOSH Division
Source Name
Aggregates Manager
Page last reviewed: October 8, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division