Experimental Study on the Thermal Protection Enhancement of Novel Phase Change Material Integrated Structural Firefighting Gloves under High-Heat Exposures.

Phase change material (PCM) has been widely studied for efficient thermal management. This work is the first holistic experimental research on the temperature control performance of PCM-integrated firefighters' gloves. The results showed that the thermal protection time could be extended by 2-5 times in the direct contact to hot object tests and around 1.5 times under the radiant/convective heat source tests when embedding a 1-mm-thick PCM layer in gloves. The PCM of melting point 68°C showed the best thermal protection performance in all test conditions since it had the most efficient phase change function during the heating process. Considering the PCM location effect, the PCM with lower melting point (68°C) showed better performance when located close to external environment (heat source) and the PCM with higher melting point (108°C and 151°C) showed better performance when located close to hand. The optimum PCM thickness would be in the range of 0.5-1.0 mm for both thermal protection improvement and hand dexterity purposes. In addition, the time for continuous temperature rises on the hand surface at post-heat exposure was longer when embedding PCM in firefighters' gloves due to the stored latent heat in PCM.

Next-Generation Custom-Fit Reusable Respiratory Protective Device with Continuous Fit Monitoring - Part II: Continuous Fit Monitoring.

Filtering facepiece respirators (FFRs) are manufactured in discrete sizes, with some models being limited in accommodating the fit of some sex and race combinations. This study presents the development of a custom-fit respiratory protective device (RPD) which conforms to a user's facial features and flexes and moves with facial movements during use. Our design also integrates a pressure-sensing network, which continuously monitors fit and will alert the user when the fit is compromised. In this Part II of the three-part series, we design and incorporate a continuous fit monitoring system in the RPD designed in Part I to enhance its role in protecting users from inhalation hazards in an effective manner during its use. The fit monitoring system comprises a fabric-based sensor network integrated into the RPD and an Android-based App designed to alert the user when the pressure at the faceseal falls below a given threshold established during the initial configuration of the RPD for the user. We also develop algorithms for the incorporation of the sensor slots and data buses into the custom-fit RPD using the Taxonomy of Landmarks defined in Part I. We enhance the structure developed in Part I to secure the sensor network during the use of the RPD. We develop algorithms for customizing a fastening hub to suit the head profiles of individuals to enable them to don the RPD quickly, easily, effectively, and in a repeatable manner. We demonstrate the successful application of the total design methodology by creating digital prototypes for three individuals with different facial profiles and make further advances to our goal of ensuring equitable respiratory protection for all including children, for whom RPDs are currently limited.

The Necessity for Improved Hand and Finger Protection in Mining.

Injuries associated with hands and fingers are highly prevalent in mining and identifying factors associated with these injuries are critical in developing prevention efforts. This study identifies nonfatal injury incidence rates, nature of injury, work activities, glove usage, and sources of hand and finger injuries in the U.S. mining industry, as reported to the Mine Safety and Health Administration (MSHA) from 2011 - 2017. Hand and finger injuries occur at a rate of 6.53 per 1000 full-time employees, which is nearly double the rate of the next highest affected body part, the back. Most of the hand and finger injuries were classified as cuts/lacerations/punctures (53%) followed by bone fractures/chips (26%). Materials handling and maintenance/repair were common activities at the time of the incident with miscellaneous metals (pipe, wire, guarding) and hand tools as the primary sources of hand and finger injury. Although the information on glove use was limited, leather gloves were most often worn when an injury occurred. When worn, gloves were found to contribute to 20% of the injuries, indicating their potential to protect the hands, but also potentially put the hands at risk. Further research is necessary to determine performance requirements for gloves used in mining operations, specifically those offering cut and puncture resistance.

Modeling and Analyzing for Thermal Protection of Firefighters' Glove by Phase Change Material.

Firefighter injures caused by burns and thermal stress occupies around 5%-10% of the total injuries annually. Glove is the thinnest/weakest components among the firefighter turnout gear, which can put firefighters, are at risk of severe wrist and hand burns during fire calls. Burns can occur quickly and enhancing the thermal protective performance of firefighters' gloves will prevent these burns. One-dimensional (1D) heat transfer modeling and simulations were performed through the COMSOL Multiphysics software to investigate the improvement of thermal protective performance when integrating a Phase Change Material (PCM) layer into a conventional structural firefighting glove. Parametric studies were conducted to explore the effects of PCM thermal properties, layer thickness, and location in glove structure on hand protection. It was found that a PCM with a higher density, specific heat, and latent heat of fusion had a larger heat capacity and thermal inertia, resulting in better thermal protective performance. The optimum melting point of PCM was found to be in the range of 80°C-140°C. A PCM layer with a thickness of 0.5 mm-1.0 mm showed sufficient thermal protection. The location of the PCM layer should be close to the inner glove surface for high-heat situations. Overall, modeling suggests that the addition of a PCM layer could significantly enhance the thermal protective performance of firefighters' gloves, with results showing increased time (2-4 times as long) for skin to reach second-degree burn temperature when compared to the conventional glove without PCM.

A taxonomy of surface mining slip, trip, and fall hazards as a guide to research and practice.

Slips, trips, and falls (STFs) are the second leading cause of non-fatal injuries and can lead to fatal incidents in the mining industry. Hazard identification is an essential first step in remediating STF hazards and creating a safer work environment. Previous research has identified industry-specific risk factors for STFs, evaluated exposures to those risk factors, and developed taxonomies of the hazards for the construction and farming sectors. In comparison, ErgoMine-a mobile device application-based ergonomics audit tool-is the only systematic evaluation tool that covers STF hazards in the mining industry. However, ErgoMine was not specifically developed to address STF hazards. This paper describes the development of a taxonomy that helps identify STF hazards at surface mining sites and provides recommendations to address these hazards to inform future evaluation tools. The objective was to develop a taxonomy that was self-explanatory, observable, repeatable, and solution oriented. In addition to current regulations, standards and guidelines were used to develop the taxonomy to ensure the focus was beyond basic compliance. A detailed description of how the STF hazard taxonomy was created for walkways, stairways, and fixed ladders is provided, along with two specific applications of its use. The STF hazard taxonomy can be used to develop tools like checklists and ergonomics audits to identify and remediate slip, trip, and fall hazards at surface mining facilities, thereby improving worker safety.

Analysis of Fall-Related Imminent Danger Orders in the Metal/Nonmetal Mining Sector.

Within the metal/nonmetal mining sector, fall-related incidents account for a large proportion of fatal and non-fatal injuries. However, the events and contributing factors leading up to these incidents have not been fully investigated. To help provide a clearer picture of these factors, an analysis of imminent danger orders issued by the Mine Safety and Health Administration (MSHA) between 2010 and 2017 at both surface and underground metal/nonmetal mine sites revealed that most orders are associated with fall risks. Of these cases, 84% involved the workers not using fall protection, fall protection not being provided, or the improper use of fall protection. Fall risks for workers most frequently occurred when standing on mobile equipment, performing maintenance and repairs on plant equipment, or working near highwalls. In most cases, a single, basic, corrective action (e.g., using fall protection) would have allowed workers to perform the task safely. Overall, these findings suggest that a systematic approach is needed to identify, eliminate, and prevent imminent danger situations. Furthermore, to protect mineworkers from falls from height, frequently performed tasks requiring fall protection should be redesigned to eliminate the reliance on personal fall protection.

Effects of Metatarsal Work Boots on Gait During Level and Inclined Walking.

Footwear plays an important role in worker safety. Work boots with safety toes are often utilized at mine sites to protect workers from hazards. Increasingly, mining operations require metatarsal guards in addition to safety toe protection in boots. While these guards provide additional protection, the impact of metatarsal guards on gait are unknown. This study aimed to measure the effects of 4 safety work boots, steel toe, and steel toe with metatarsal protection in wader- and hiker-style boots, on level and inclined walking gait characteristics, during ascent and descent. A total of 10 participants completed this study. A motion capture system measured kinematics that allowed for the calculation of key gait parameters. Results indicated that gait parameters changed due to incline, similar to previous literature. Wader-style work boots reduced ankle range of motion when ascending an incline. Hip, knee, and ankle ranges of motion were also reduced during descent for this style of boot. Wader-style boots with metatarsal guards led to the smallest ankle range of motion when descending an inclined walkway. From these results, it is likely that boot style affects gait parameters and may impact a miner's risk for slips, trips, or falls.

A General Framework to Test and Evaluate Filtering Facepiece Respirators Considered for Crisis Capacity Use as a Strategy to Optimize Supply.

During a public health emergency, respirator shortages can have a profound impact on the national response, such as for the current coronavirus disease 2019 (COVID-19) pandemic. Due to a severe shortage of respirators (particularly filtering facepiece respirators [FFRs]), there may be contexts in which understanding the performance of FFRs that are approved for use as part of a crisis capacity strategy is desired. This includes FFRs that are not covered under the National Institute for Occupational Safety and Health (NIOSH) Respirator Approval Program because they have been stored past their designated shelf life, have been decontaminated, or are approved by international certification bodies other than NIOSH. The purpose of this document is to provide a general framework to assess the performance of FFRs that are only being used as a crisis capacity strategy. The intended audience are those who are responsible for managing large amounts of FFRs. This framework includes a four-step process consisting of: 1) defining the population of FFRs to be sampled; 2) providing sampling strategy options; 3) inspecting and testing the sampled units; and 4) evaluating the results. In addition to the four-step process, we provide an example of how NIOSH recently evaluated the quality of FFRs sampled from ten U.S. stockpiles.

Operators' views of mobile equipment ingress and egress safety.

A large proportion of non-fatal slips, trips, and falls (STFs) at surface mining facilities are associated with mobile equipment. Ingress and egress from mobile equipment can pose a fall risk to mobile equipment operators. The objective of this study was to determine mobile equipment operators' views of STF risks from mobile equipment, and to ascertain what factors, tasks, and conditions they perceive as contributing to these risks. A thematic analysis of 23 individual interviews and 2 group interviews was conducted, with 10 overarching themes identified from the transcripts. Mobile equipment operators indicated that being unable to see their feet or the ladder rungs during descent and the presence of contaminants on the ladders caused by normal operation make egress more dangerous than ingress. The flexible rails and high heights of the lower rungs identified over 40 years ago as issues for mobile equipment operators still pose a perceived STF risk. Further, the requirements of routine maintenance tasks such as oil and filter changes, greasing, and cleaning windows pose fall risks due to inadequate access and the need to carry supplies up and down equipment ladders. In addition to the mobile equipment, hazardous ground conditions and insufficient lighting were found to be key issues around the mobile equipment and in parking areas. The findings of this work indicate that mobile equipment operators feel at risk for STFs due to the design and condition of their equipment, and would like to see ladders replaced with safer stairways as the primary ingress/egress system.

Emerging Ergonomics Issues and Opportunities in Mining.

Ergonomics is the scientific discipline that investigates the interactions between humans and systems to optimize both human and system performance for worker safety, health, and productivity. Ergonomics is frequently involved either in the design of emerging technologies or in strategies to alleviate unanticipated human performance problems with emerging technologies. This manuscript explores several such emerging issues and opportunities in the context of the mining sector. In mining, the equipment, tools, and procedures have changed considerably and continue to change. Body-worn technology provides a number of opportunities to advance the safety and health of miners, while teleoperation and autonomous mining equipment stand to benefit significantly from ergonomics applications in other sectors. This manuscript focuses on those issues and opportunities that can impact the safety and health of miners in the near term.

An analysis of injuries to front-end loader operators during ingress and egress.

Slips, trips, and falls from mobile mining equipment have been documented for decades. However, little research has been conducted to determine the events precipitating these incidents during ingress or egress. This study examined slips, trips, and falls sustained during ingress or egress from front-end loaders to determine the frequencies of factors that may contribute to injuries. Non-fatal injuries, when getting on or off of front-end wheel loaders specifically, were identified, coded, and analyzed from the Mine Safety and Health Administration's accidents, injuries, and illnesses database. Overall trends, events that precipitated the injury, injuries sustained, contributing factors, location of the individual, and equipment characteristics were analyzed. More incidents occurred during egress (63%); and egress is believed to be more hazardous than ingress. Foot slips were the most common event that precipitated the incident and the leading cause of these was contaminants on the equipment. Misstep, loss of footing, and step on/in related incidents were more common during egress and are likely due to the operator's reduced visibility when descending a ladder facing the equipment, limiting their ability to detect hazards. Egress also makes an operator less capable of avoiding unsafe ground conditions as indicated by the significant number of step on/in injuries occurring on the ground during egress. Most of the front-end loaders associated with the incidents were found to have bottom rungs with flexible rails, which may also increase fall risk during egress due to inconsistent rung heights and lengthy transition areas from the ground, through the flexible-railed rungs, to the rungs with rigid rails. Recommendations are provided to reduce the risk for slips, trips, and falls from mobile mining equipment.

Method for measuring wear on boot outsoles using a 3D laser scanner.

In the mining industry, slips and falls are the second leading cause of non-fatal injuries. Footwear is the primary defence against a slip; consequently, the condition of the footwear outsole is critical to maintaining slip resistance. Currently, there is no published method that can be used to determine when the outsole no longer affords adequate slip protection. Moreover, quantifying the condition of the outsole through the measurement of outsole features can be tedious. This article introduces a new method for the quantification of boot outsole wear. Using a handheld 3D scanner, boot scans can be taken quickly and the developed models used to measure outsole features. This method also accounts for the bending of the boot due to normal wear, which may otherwise introduce erroneous measures. When compared to measurements with a traditional handheld calliper, this new method offers more flexibility in terms of data collection, accounts for other types of boot transformations, and is more efficient to use over multiple measurement periods with no statistically significant differences in measurement.

Development of ergonomics audits for bagging, haul truck and maintenance and repair operations in mining.

The development and testing of ergonomics and safety audits for small and bulk bag filling, haul truck and maintenance and repair operations in coal preparation and mineral processing plants found at surface mine sites is described. The content for the audits was derived from diverse sources of information on ergonomics and safety deficiencies including: analysis of injury, illness and fatality data and reports; task analysis; empirical laboratory studies of particular tasks; field studies and observations at mine sites; and maintenance records. These diverse sources of information were utilised to establish construct validity of the modular audits that were developed for use by mine safety personnel. User and interrater reliability testing was carried out prior to finalising the audits. The audits can be implemented using downloadable paper versions or with a free mobile NIOSH-developed Android application called ErgoMine. Practitioner Summary: The methodology used to develop ergonomics audits for three types of mining operations is described. Various sources of audit content are compared and contrasted to serve as a guide for developing ergonomics audits for other occupational contexts.

The effect of vibration exposure during haul truck operation on grip strength, touch sensation, and balance.

Falls from mobile equipment are reported at surface mine quarry operations each year in considerable numbers. Research shows that a preponderance of falls occur while getting on/off mobile equipment. Contributing factors to the risk of falls include the usage of ladders, exiting onto a slippery surface, and foot or hand slippage. Balance issues may also contribute to fall risks for mobile equipment operators who are exposed to whole-body vibration (WBV). For this reason, the National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research conducted a study at four participating mine sites with seven haul truck operators. The purpose was to ascertain whether WBV and hand-arm vibration (HAV) exposures for quarry haul truck operators were linked to short-term decreases in performance in relation to postural stability, touch sensation threshold, and grip strength that are of crucial importance when getting on/off the trucks. WBV measures of frequency-weighted RMS accelerations (wRMS) and vibration dose value (VDV), when compared to the ISO/ANSI standards, were mostly below levels identified for the Health Guidance Caution Zone (HGCZ), although there were instances where the levels were within and above the specified Exposure Action Value. Comparably, all mean HAV levels, when compared to the ISO/ANSI standards, were below the HGCZ. For the existing conditions and equipment, no significant correlation could be identified between the WBV, HAV, postural stability, touch sensation threshold, and grip strength measures taken during this study.

Evaluating the Use of Stretchers in Two Mobile Refuge Alternatives.

In a mine emergency where refuge is necessary, miners may sustain injuries that will render them unable to walk or crawl. In this situation, a miner may have to rely on others for transportation into the mobile refuge alternative (RA) while on a stretcher. Since requirements for mine first-aid stations were developed before RAs, stretchers should be evaluated to determine whether they are usable in an RA and within the physical capabilities of miners in a refuge. The size of the RA airlock is a concern, as it has not been determined if current airlocks will accommodate a miner on a stretcher. This study evaluated the time required to move three types of stretchers into two commercially available RAs. The splint stretcher had the longest average time to move into each RA as compared to the backboard and soft stretcher. This increase was mostly due to the increased time requirements for getting the splint stretcher into the airlock. For all stretchers, it took approximately two to three times longer to enter the inflatable tent-type RA compared to the rigid steel RA. Mining companies should consider how well their current first-aid implements work with their RAs and manufacturers of inflatable RAs should maximize the size of the outer doors leading into the airlock to allow an easier entry for stretchers.

Off-road truck-related accidents in U.S. mines.

INTRODUCTION: Off-road trucks are one of the major sources of equipment-related accidents in the U.S. mining industries. A systematic analysis of all off-road truck-related accidents, injuries, and illnesses, which are reported and published by the Mine Safety and Health Administration (MSHA), is expected to provide practical insights for identifying the accident patterns and trends in the available raw database. Therefore, appropriate safety management measures can be administered and implemented based on these accident patterns/trends. METHODS: A hybrid clustering-classification methodology using K-means clustering and gene expression programming (GEP) is proposed for the analysis of severe and non-severe off-road truck-related injuries at U.S. mines. Using the GEP sub-model, a small subset of the 36 recorded attributes was found to be correlated to the severity level. RESULTS: Given the set of specified attributes, the clustering sub-model was able to cluster the accident records into 5 distinct groups. For instance, the first cluster contained accidents related to minerals processing mills and coal preparation plants (91%). More than two-thirds of the victims in this cluster had less than 5years of job experience. This cluster was associated with the highest percentage of severe injuries (22 severe accidents, 3.4%). Almost 50% of all accidents in this cluster occurred at stone operations. Similarly, the other four clusters were characterized to highlight important patterns that can be used to determine areas of focus for safety initiatives. CONCLUSIONS: The identified clusters of accidents may play a vital role in the prevention of severe injuries in mining. Further research into the cluster attributes and identified patterns will be necessary to determine how these factors can be mitigated to reduce the risk of severe injuries. PRACTICAL APPLICATION: Analyzing injury data using data mining techniques provides some insight into attributes that are associated with high accuracies for predicting injury severity.

Identification of Work-Related Musculoskeletal Disorders in Mining.

Work-related musculoskeletal disorder (WMSD) prevention measures have been studied in great depth throughout various industries. While the nature and causes of these disorders have been characterized in many industries, WMSDs occurring in the U.S. mining sector have not been characterized for several years. In this report, MSHA accident/injury/illness data from 2009 to 2013 were characterized to determine the most frequently reported WMSDs in the U.S. mining sector. WMSDs were most frequently reported in workers with less than 5 years or more than 20 years of mining experience. The number of days lost from work was the highest for shoulder and knee injuries and was found to increase with worker age. Underground and surface coal, surface stone and stone processing plants experienced the greatest number of WMSDs over the period studied. WMSDs were most commonly caused by an employee suffering from an overexertion, falls or being struck by an object while performing materials handling, maintenance and repair tasks, getting on or off equipment or machines, and walking or running. The injury trends presented should be used to help determine the focus of future WMSD prevention research in mining.

Slip Potential for Commonly Used Inclined Grated Metal Walkways.

BACKGROUND: No specific guidelines or regulations are provided by the Mine Safety and Health Administration for the use of inclined grated metal walkways in mining plants. Mining and other companies may be using walkway materials that do not provide sufficient friction, contributing to slip and fall injuries. PURPOSE: The purpose of this study was to determine if there are significant differences in the required friction for different grated metal walkways during walking in diverse conditions. METHODS: The normalized coefficients of friction were measured for 12 participants while walking up and down an instrumented walkway with different inclinations (0°, 5°, 10°, 15°, and 20°) and with and without the presence of a contaminant (glycerol). Self-reported slip events were recorded and the required coefficients of friction were calculated considering only the anterior/posterior components of the shear forces. Additionally, the available coefficients of friction for these walkway materials were measured at the 0° orientation using a tribometer, with and without the presence of the contaminant, using a boot heel as well as Neolite as the test feet. RESULTS: The number of slips increased when the inclination angle reached 10° and above. Of all materials tested, the diamond weave grating was found to have the best performance at all inclines and when contaminated or dry. A high number of slips occurred for the perforated grating and serrated bar grating at 20° when contaminated. CONCLUSIONS: Results of this study suggest that the diamond weave grating provides significantly better friction compared to serrated bar and perforated gratings, especially at inclines greater than 10°.

Maintenance and repair injuries in US mining.

PURPOSE ­: The purpose of this paper is to identify key tasks, tools, and equipment associated with maintenance and repair injuries at US mines and to provide some mitigation strategies to reduce these types of injuries. DESIGN/METHODOLOGY/APPROACH ­: This study analyzed incidents resulting in injuries reported to the US Mine Safety and Health Administration from 2002 to 2011. Incident reports were limited to those occurring at mining plants, shops, yards, and aboveground locations. Incident reports were analyzed to determine which activities contributed to injuries and were due to machine maintenance and repair, non-powered hand tools, and powered hand tools. An in-depth analysis of the root causes of these injuries was then performed. FINDINGS ­: Maintenance and repair in mining is associated with a significant number of hand and finger injuries with a range of severities and averaging over 20 amputated fingers, 180 fractured hands and fingers, and 455 hand and finger lacerations per year. Many of these injuries are caused by hands being struck by or caught in tools and equipment. Back and shoulder strains are found to be associated with the most days lost from work and are mostly attributed to materials handling. PRACTICAL IMPLICATIONS ­: Occupational injuries and fatalities still occur with high incidences in the mining sector. The mission of the Office of Mine Safety and Health Research (OMSHR; part of the National Institute for Occupational Safety and Health, NIOSH) is to "eliminate mining fatalities, injuries, and illnesses through research and prevention." As part of this work, OMSHR acquires surveillance data from MSHA to quantify the types and sources of injuries at US mining facilities. The authors evaluated maintenance- and repair-related injuries at US mining sites (excluding underground coal mines). Results of this study suggest a need for improved design of machine guarding, improved hand protection through gloves and equipment design/redesign, and manual materials handling solutions. ORIGINALITY/VALUE ­: The findings indicate that maintenance and repair in mining include occupational risks that may be managed through modifications to machines, proper usage of hand tools and hand protection, and improved manual materials handling processes.