Ergonomics processes: implementation guide and tools for the mining industry

"Research has shown that an ergonomics process that identifies risk factors, devises solutions to reduce musculoskeletal disorders (MSDs), and evaluates the effectiveness of the solutions can lower worker exposure to risk factors and MSDs and improve productivity. A review of the Mine Safety and Health Administration (MSHA) injury/illness database indicated that 46% of illnesses in 2004 were associated with repetitive trauma and 35% of nonfatal lost days involved material handling during 2001- 2004. Even though these statistics show that MSDs significantly contribute to occupational illnesses and injuries in the U.S. mining industry, few mining companies have implemented an ergonomics process. Despite the many unique challenges in the mining environment, three mining companies partnered with the MSD Prevention Team at the National Institute for Occupational Safety and Health's Pittsburgh Research Laboratory to demonstrate that an ergonomics process could be systematically implemented and effectively integrated with existing safety and health programs. Because these three mining companies were very different in organization, culture, and size, the ergonomics processes had to be modified to meet the needs of each company. A description of how these three companies applied ergonomics and the tools and training used to implement their processes is given. Prior to discussing the case studies, general information on the elements of an ergonomics process is provided.' - NIOSHTIC-21. Introduction: Ergonomics and risk management -- 2. Ergonomics processes: case studies -- 3. Process effectiveness -- 4. Implementation tools -- 5. Training -- References -- Appendix: Ergonomics processes: beyond traditional safety and health programsby Janet Torma-Krajewski, Lisa J. Steiner, Robin Burgess-Limerick."February 2009."Also available via the World Wide Web.Includes bibliographical references

New technology for coal mine roof support

"Roof falls continue to be the greatest single safety hazard faced by underground coal miners. During 1996-99, 44 coal miners lost their lives in rock falls, and nearly 2,400 were injured. In addition, nearly 6,000 noninjury roof collapses were reported. Roof supports are installed to protect the miners, but support system failures contributed to most of these incidents. Reducing the terrible toll taken by ground falls continues to be a major goal of research by the National Institute for Occupational Safety and Health (NIOSH). The purpose of these proceedings is to provide the mining community with a comprehensive survey of coal mine roof supports. Drawing on many years of research undertaken by the NIOSH Pittsburgh and Spokane Research Laboratories, this volume describes what types of support are available, how they work, and when they should be used. The major subjects covered include roof bolts, standing roof supports, cable supports, and longwall shields. Some special topics are also addressed, including an analysis of roof fall accident statistics, techniques for better skin control, materials handling considerations, and longwall mining through recovery rooms. This proceedings volume also contains information on several important new technologies, which are described here for the first time: - Guidelines for selecting roof bolt length, pattern, and capacity that were derived from statistical analysis of the roof fall experience at 37 underground mines; - A new design method for longwall tailgate supports; and - A technique for measuring loads developed within cable bolts. http://www.cdc.gov/niosh/mining/pubs/pdfs/2000-151-errata.pdf " - NIOSHTIC-2edited by Christopher Mark, Dennis R. Dolinar, Robert J. Tuchman, Thomas M. Barczak, Stephen P. Signer and Priscilla F. Wopat.NIOSHTIC no 20000874Includes bibliographical references

Explosion effects on mine ventilation stoppings

"The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research to evaluate explosion blast effects on typical U.S. mine ventilation stoppings in the NIOSH Pittsburgh Research Laboratory's (PRL) Lake Lynn Experimental Mine (LLEM). An innovative Australian-designed brattice stopping was also evaluated. After mine explosion accidents, MSHA conducts investigations to determine the cause(s) as a means to prevent future occurrences. As part of these postexplosion investigations, the condition of underground stoppings, including the debris from damaged stoppings, is documented as evidence of the approximate strength and the direction of the explosion forces. The LLEM data showed that a typical dry-stacked and coated solid-concrete-block stopping survived a total explosion pressure of ~6.7 psi (~46 kPa) and was destroyed at a total explosion pressure of ~7.6 psi (~52 kPa). In comparison, a typical dry-stacked and coated hollow-core concrete block stopping survived a total explosion pressure of ~3.4-4.3 psi (~23-30 kPa) and was destroyed at a total explosion pressure of ~3.6-5.2 psi (~25-36 kPa), depending on the length of the pressure pulse and the value of the pressure-time integral. A typical steel panel stopping design survived a total explosion pressure of 0.8 psi (5.5 kPa) and failed at a total explosion pressure of 1.3 psi (9 kPa). The LLEM data also showed that an obstacle blocking the path of a pressure wave resulted in a higher reflected pressure at the obstacle. An 8-in (20-cm) thick wet-laid solid concrete-block stopping coated on one side survived a total explosion pressure of ~26 psi (~180 kPa); this stopping was not tested to failure. A 6-in (15-cm) thick wet-laid solid-concrete block stopping coated on one side survived a total explosion pressure of ~14 psi (~97 kPa) and was destroyed at a total explosion pressure of ~25 psi (~172 kPa). An innovative Australian woven cloth stopping survived an explosion pressure of 4.0 psi (27 kPa) and was destroyed at an explosion pressure of ~6.1 psi (~42 kPa). These results will help investigators determine the approximate explosion forces that destroy or damage stoppings during actual coal mine explosions." - NIOSHTIC-2by Eric S. Weiss, Kenneth L. Cashdollar, Samuel P. Harteis, Gary J. Shemon, Dennis A. Beiter, and John E. Urosek"November 2008."Also available via the World Wide Web.Includes bibliographical references (p. 92-93)

Miner training simulator: user's guide and scripting language documentation

"A training software package for new mine employees, called Miner Training Simulator (MTS), has been developed by researchers at the National Institute for Occupational Safety and Health. MTS is a computer-based tool that allows a trainee to enter a simulated mine and interact with his/her surroundings in order to learn basic mining concepts, safety procedures, mine layouts, and escape routes. The training simulator software and instructions for its use are described in this report. Also, each mine using the software will have different requirements with regard to safety training. To customize the simulator for these differences, an interpreted scripting language is used to define interactions between the trainee and the virtual mine and objects in it. The scripting language, called Tool Command Language, uses simple commands to control various actions in the simulation, such as sounds, safety messages, hazards, and movement of objects. The basics of the scripting language are described here, along with many examples and instructions for building a script for MTS." - NIOSHTIC-2by Todd M. Ruff."June 2001."Also available via the World Wide Web.Includes bibliographical references (p. 11)

A Performance evaluation of two overhead power line proximity warning devices

"Accidental contact of overhead electrical power lines by mobile equipment is a leading cause of occupational fatalities in the United States, accounting for 20% of on-the-job electrocutions. Overhead electrical power line proximity warning devices (PWDs) are intended to warn personnel if mobile equipment moves within some preselected minimum distance of an energized overhead electrical power line. Two commercially available PWDs were tested at the National Institute for Occupational Safety and Health's (NIOSH) Pittsburgh Research Laboratory (PRL). The objective of the tests was to document performance capabilities and limitations for these PWDs by identifying factors that can influence their operation. The two PWDs evaluated in this research are the SIGALARM Model 210 marketed by Allied Safety Systems, LLC, and the ASE Model 2100 from Allied Safety Engineering. Both of these devices operate by measuring the electric field present around energized power lines. The PWDs were installed on a government-owned 22-st (20-mt) rough terrain crane. A purpose-built test site used for this research at PRL allowed operation of the crane near a variety of power line configurations operating at up to 25 kV. Most of the tests involved positioning the crane adjacent to one or more overhead power lines, adjusting sensitivities of the PWDs to alarm when the crane boom was approximately 20 ft (6.1 m) from the power lines, swinging the crane boom toward the lines under a wide variety of test conditions, and finally, for each unique set of test conditions, documenting the deviation from 20 ft (6.1 m) for actual alarm activation. Test results show that several factors can adversely affect PWD performance. PWD alarm accuracy generally deteriorated when operating with a boom position significantly different than that used for the device's last sensitivity adjustment. Another factor that can affect PWD performance is configuration of the overhead power line(s) involved. Accuracy of alarm activation distances was best for simple single-circuit installations, but degraded for multiple circuits on the same poles. This degradation was slightly greater for installations with different voltage levels and/or a combination of vertical and horizontal conductor arrangements. Performance also degraded for crane operation between two intersecting power line installations, especially for intersecting lines at different voltages. An additional aspect of power line configuration shown to influence PWD accuracy was phase sequence on the power line circuit(s). Specific phase conductor arrangements and combinations, particularly in multiple circuit installations, resulted in either improved or degraded accuracy. Tests were also conducted to evaluate the PWDs as "early warning devices" for situations such as moving a mobile crane into an unfamiliar work area. Results showed that the SIGALARM Model 210 could detect energized 13-kV power lines at a distance of 75-88 ft (22.9-26.8 m). This alarm distance would allow an operator to take preventive measures before the crane is in a position from which it could contact nearby power lines. " - NIOSHTIC-2by Gerald T. Homce, James C. Cawley, and Michael R. Yenchek."November 2008.""CDC workplace safety and health"--Cover.Also available via the World Wide Web.Includes bibliographical references (p. 36)

Nitrogen dioxide calibration standards for portable monitors

"Mine operators and Mine Safety and Health Administration inspectors use portable gas monitors in underground mines to measure worker exposure to various gases such as methane, carbon monoxide, and nitrogen dioxide (NO2). Even in relatively small concentrations, NO2 can produce harmful side effects in underground workers. Mines using equipment powered by diesel engines, carrying out explosive blasting operations, and performing extensive arc welding and/or cutting work will have measurable quantities of NO2 released by these processes. Workers in these areas often use gas monitors to warn of excessive gas concentrations and to help them determine when to increase ventilation air that will dilute these gases, thus minimizing exposures to this gas. Portable gas monitors, used to measure NO2 levels, must be calibrated before each use. Calibration is typically performed using a small portable pressurized cylinder containing a certified gas mixture. The certified NO2 standard mixture, usually 10 ppm NO2 concentration, is diluted with either air or nitrogen gas. To determine the stability of commercially available portable gas standards, two different cylinders containing NO2 in nominal 10-ppm concentrations were examined. One cylinder was diluted in air, the other, in nitrogen. Baseline NO2 mixtures were generated using a standard liquid NO2 permeation tube operated at a constant temperature. Final dilutions of the test gas mixtures were made with air or with nitrogen using a mass flow-controlled gas dilution system. This study showed that, when a permeation-type NO2 generator is used, the electrochemical sensors in portable NO2 monitors provide identical results for gas mixtures whether they are diluted with air or with nitrogen. Two different gas monitors, one with a two-electrode sensor and one with a three-electrode sensor, were used to measure gas concentrations in the two commercially available cylinders. One month after the cylinders were delivered, the NO2-in-nitrogen cylinder, stated to contain 10 ppm NO2, measured 8.13 ppm. The NO2-in-air cylinder, also stated to hold 10 ppm NO2, measured 6.88 ppm. Therefore, before using NO2 gas cylinders to calibrate monitors, it is recommended that their concentrations be verified either by manufacturer recertification or by comparing the stated cylinder gas concentrations to a laboratory-based permeation tube-generated standard. " - NIOSHTIC-2by Joseph E. Chilton, Robert J. Timko, and Edward J. Chuhta."December 2005."Also available via the World Wide Web.Includes bibliographical references (p. 8)

Prediction of longwall methane emissions: an evaluation of the influence of mining practices on gas emissions and methane control systems

"The primary purpose of this field study was to predict the methane emission consequences of mining longwall panels of greater face width in the Pochontas No. 3 Coalbed in Virginia. Mines were to be increased from 229 to 305 m (750 to 1,000 ft). However, since historically high methane emissions from the longwall face and gobs were already being experienced, there was a concern for further increases in methane emission rates. If preferables from a safety perspective to be prepared in advance, either with increased ventilation airflow, or with additional methane drainage. The bleeder and methane drainage systems associated with the two study panels were also evaluated to fully characterize the methane liberation patterns and control system performance for each study area. " - NIOSHTIC-2William P. Diamond and Fred Garcia."October 1999."Includes bibliographical references (p. 32)

Reducing hazardous dust exposure when rock drilling during construction

"Construction workers may be exposed to hazardous dust containing crystalline silica during site preparation when drilling systems are used. The National Institute for Occupational Safety and Health (NIOSH) found that drill dust could be decreased by using wet or dry dust reduction engineering controls, enclosed cabs, and implementing a dust control program." - NIOSHTIC-2"The principal contributors to this publication were John Organiscak, Andrew Cecala, and Steven Page of the Pittsburgh Research Laboratory, National Institute for Occupational Safety and Health. John Whalen under a contract with the U.S. Public Health Service, Division of Federal Occupational Health served as writer/editor." - acknowledgements"April 2009."Also available via the World Wide Web

NIOSH releases new skills training aid: walk-thru roof bolting machine trainer's guide

"In the U.S. coal mining industry, a large cohort of miners is at or nearing retirement age. As these miners retire, there will be a need to hire and train thousands of new and most likely younger workers. Moreover, a large portion of safety trainers will also require replacement due to retirement. In a speech before the U.S. House of Representatives (2004), Bruce Watzman, Vice President for Safety, Health and Human Resources for the National Mining Association said, '[W]e will need to replace a major portion, approximately 50%, of the underground coal mining workforce within the next 5-7 years.' The large influx of new mine workers, along with the deficit in safety trainers, creates the challenge to provide consistent and effective safety training. Given the expected high turnover of the mining workforce, it is very likely that incoming workers will have much less experience than those leaving the workforce. Unfortunately, inexperienced miners have been shown to incur the highest rate of injuries. The piece of machinery most associated with these injuries is the roof bolting machine, which accounts for 56% of machinery-related injuries in underground coal mining. The National Institute for Occupational Safety and Health (NIOSH) has released a new report entitled 'Roof Bolting Machine Operators Skills Training for a Walk-Thru Roof Bolter: Trainer's Guide' (IC 9489). It is designed to help safety trainers develop structured training for new operators of walk-thru bolting machines. This resource will help trainees learn, understand, and apply knowledge and skills. Included in the trainer's guide are the following tools: a six-part DVD video series, a skills check survey, talking points, and a complete job training analysis. Also included is an exercise to help trainees learn more about their mine's roof control plan, as well as a list of supplemental training and reading materials. On-site trainers can modify this guide to fit their particular mine conditions, machines and equipment, and work procedures. The goal of every coal mine safety professional is to increase safety awareness and make mines a safer place to work. The Walk-Thru Bolting Machine Trainer's Guide will help teach new miners skills to create a safer working environment that will ultimately prevent or reduce on-the-job injuries. Safety trainers can also use the ideas and concepts from this guide to develop their own training skills for the safe operation of other pieces of underground coal mining equipment." --NIOSHTIC-2"Milestones in Mining Safety and Health Technology.

The Application of major hazard risk assessment (MHRA) to eliminate multiple fatality occurrences in the U.S. minerals industry

"Major Hazard Risk Assessment (MHRA) is used to help prevent major hazards, e.g., fire, explosion, wind-blast, outbursts, spontaneous combustion, roof instability and chemical and hazardous substances, etc., from injuring miners. The structured process associated with MHRA helps to characterize the major hazards and evaluate engineering, management and work process factors that impact how a mine mitigates its highest risk. The National Institute for Occupational Safety and Health (NIOSH) studied the application of this technique to US mining conditions through a field-oriented pilot project. Risk assessment teams used in the pilot project were primarily composed of mining company personnel. Ten case studies were performed over a wide cross-section of mines. These mines were representative of the important mining commodities in the US minerals industry, i.e. coal, metal, non-metal, and aggregate. Also, the sizes of the mines ranged from small to large and were located across the country. The ten case studies demonstrate that most US mines have the capability to successfully implement an MHRA and that the MHRA methodology produced additional prevention controls and recovery measures to lessen the risk associated with a select population of major mining hazards. The basic ingredient for a successful MHRA is the desire to become more proactive in dealing with the risks associated with events that can cause multiple fatalities. A successful outcome is marked by a thorough examination of existing prevention controls and recovery measures. When pressed to consider more controls to further mitigate the risk, a well-staffed risk assessment team was able to identify additional controls. For these mining operations, it was important to add additional controls, even if they were not required by existing mining regulations, to lower the risks associated with the major hazards under consideration. If a mining operation is not willing to commit its best people to an MHRA or will not provide them with sufficient time to see the process through to its conclusion, the MHRA output may prove to be useless. Additionally, if a mining operation is not prepared to discuss its major hazards in an open and honest fashion and to present the findings of the risk assessment in a written report, the MHRA output will be unclear, and attempts to monitor or audit important controls may not be possible. A MHRA is most effective when the mining operation possesses 1) a proper understanding of its hazards, 2) experience with informal and basic-formal risk assessment techniques, 3) proper facilities, machinery and equipment, 4) suitable systems and procedures that represent industry Best Practice, 5) appropriate organizational support with adequate staff, communications and training, 6) a formal and thorough plan for emergency response, and 7) a safety risk management approach that is promoted and supported at all levels of the organization." - NIOSHTIC-2by A. Iannacchione, F. Varley and T. Brady."October 2008."Also available via the World Wide Web.Includes bibliographical references (p. 121-122)