Part 1 of this series of articles identifies electric arc classification, properties, behavior and methods of thermal energy dissipation among the different types of arcs, and factors for the future progress in electric-arc-rated (AR) PPE quality and reliability. Understanding the properties and behaviors of the different possible types of electric arcs is key to assessing AR PPE.
New knowledge of electric arc classification is helpful not only in current arc incident investigation but also in better understanding past arc incidents. Analysis of specific electric arc incidents is complemented with extensive research on electrical trauma trends based on government data. Part 2 of this series addresses arc hazards, protection fundamentals, and data on electrical fatalities and arc burn trauma.
Fundamentals of Electric Arc Protection
Electric Arc Hazards
Electric arc hazards are not limited to the thermal effect. Large amounts of thermal energy released in the electric arc event is also accompanied by extremely bright light flash, momentary and residual flames, heavy smoke and poisonous fumes, loud sound and molten metal droplets. Pressure waves and flying projectiles are also likely as a result of air pressure build-up with cabinet rupture due to the extreme pressure from arcing inside the enclosed cabinet.
All kinds of AR PPE are first and foremost designed and tested to protect the body, hands, face and head from thermal effects. AR PPE may provide supplementary protection against light flash, molten metal and projectiles, but it provides limited protection against smoke, sound and chronic effects from stress caused by the arc event.
According to Bureau of Labor Statistics (BLS, 2016), 4,836 fatal work injuries were recorded in the U.S. in 2015. Stated differently, 13 American workers are tragically and unnecessarily taken from their families every day. These statistics underscore the urgent need for safer workplaces.
When the author joined the safety and health department of his former employer, he knew the company was facing some tough OSH-related challenges. To say that the employer was in deep trouble was an understatement. A few weeks after the author’s arrival at the Flint, MI, manufacturing plant, the trouble signs were too many to miss.
The 700-person, round-the-clock plant was operating at an anemic 49% efficiency, while corporate management expected a minimum efficiency of 85%. The plant also had an OSHA incidence rate of 12.6 (3.5 points higher than the industry average), high turnover, high workers’ compensation costs and a strained relationship with Michigan-OSHA (MIOSHA).
Hourly workers voiced persistent criticism of virtually every aspect of the plant, and of safety and health in particular. No matter what plant management did, it could not shake the perception that it was indifferent to employees’ safety and health. In addition, several OSHA citations originating from employee complaints led MIOSHA to put the plant on its radar. The persistent OSH-related problems (e.g., ergonomics, machine guarding, housekeeping, lockout/tagout) not only were detrimental to productivity, quality and employee morale, but also had resulted in turnover of OSH professionals. The author was the plant’s third OSH professional in less than a year.
In the course of their daily lives, people selectively attend to available information and render judgments about the state of the world. These occur in various contexts including judgments concerning one’s own performance (e.g., how well am I currently doing at this task?) or the amount of risk associated with a given situation. People also carry out, sometimes immodestly, general self-appraisals, evaluating how skillful or capable they are in different contexts. People’s perceptions of the world and of their own efficacy and ability can have important implications concerning their decision making and consequent behaviors.
From a safety perspective, it is critical to understand situations where people’s perceptions or subjective appraisals deviate from objective reality. For example, a fatigued driver may elect to continue driving because he fails to adequately recognize the signs of fatigue or overestimates his ability to safely drive. Or an inexperienced driver may be overconfident in her driving skills and abilities, and travel at a high speed on a slippery surface. Gaps in subjective and objective measures have been related to calibration, a concept that has been broadly studied in many disciplines (Zell & Krizan, 2014).
This article reviews some extant literature on calibration in various domains, and describes a conceptual driver-focused framework that depicts calibration in the context of human information processing (attention) and an array of local and global contextual factors. It also describes the implications for organizational applications and the role of new automotive technology. Lastly, it discusses potential inroads for addressing the issues of calibration in the work setting.
Pneumatic nail drivers, commonly called nail guns, are used in construction and manufacturing, especially with high-volume fabrication and production (Figure 1, p. 32). They are powered by compressed air, operated by a finger trigger and are particularly useful for repetitive, intensive operations, such as nailing wooden studs, floor joists and plywood sheathing, and fastening roofing materials such as shingles to sheathing. In the past 20 years, pneumatic nail drivers, some of which can insert up to eight fasteners per second, have effectively replaced the hammer for driving fasteners on construction sites.
Pneumatic tools have two main types of trigger modes. With a contact-actuated trigger (CAT) tool, a worker can repetitively discharge fasteners by continuously pressing the trigger and bumping the tool’s nosepiece against the work surface. With a sequential-actuated trigger (SAT) tool, the worker presses the tool’s nosepiece against the work surface and then presses the trigger to discharge a fastener. A SAT tool requires the worker to remove contact with the nosepiece and release the trigger before another fastener can be discharged. Wood frame building workers and residential roofers typically use CAT tools because they have higher production rates than SAT tools (i.e., more fasteners are installed per unit time).
Supervisors of interns must seek to retain academic quality as they help the students integrate theory and practice, moving them beyond simple experience to fuller utilization and development of their education (Karlsson, 2011). Karlsson’s study examined how well the practical experience continued the academic one. In this article, the authors describe a similar project conducted for presentation at ASSE’s annual conference (Iske & Weller, 2014). In contrast to Karlsson’s study, Iske and Weller (2014) investigated how well the students’ academic experience in one such university program prepared them for real-world internship experiences as well as the potential for improvement in the academic preparatory knowledge.
Research on internships often focuses on evaluating student success. Using internship data to validate a program’s effectiveness should prove useful to companies that use or are considering adding academic interns to their workforce. The data presented here were gathered from the internship supervisors’ evaluations of their interns from University of Central Missouri (UCM). Evaluations were submitted halfway through the semester (at midterm) and as a final evaluation at the end of the internship. For this study, only the final evaluations were considered for assessment of student performance. These data provide a great resource for continuous improvement and validation of program technical content, ensuring a top-notch educational experience for students and a benefit for the companies hiring them.
Internships & Why Employers Sponsor Them
Ferguson (1998) describes an internship as “a means of bridging the gap between the student’s education and the business world.” Internships are becoming the capstone experience for students in an increasing number of degree programs and disciplines. Internships provide exceptional experiences for students for practical employment advancement and potential employment entry. They can provide firsthand knowledge and understanding of the need to learn work skills, and development of career expectations and future goals.
OSH professionals inherently understand the value of holding certification credentials such as certified safety professional (CSP), Canadian registered safety professional (CRSP) and certified industrial hygienist (CIH), but knowledge about how the certification program is established and maintained may not be as prevalent. OSH professionals might also have questions about the process, such as who determines what topics go on the exam? How are questions written and approved for inclusion on the exam? How are passing scores determined? A great deal of science and mathematics is behind the process. This article aims to answer these questions and help explain why and how a properly developed and administered certification examination shows the mark of excellence in the field of safety and health.
Certification vs. Certificate Program
To understand the certification process, one must first understand the difference between certification and a certificate program. Professional certification is defined by Institute for Credentialing Excellence (ICE) as a “voluntary process by which a nongovernmental entity grants a time-limited recognition and use of a credential to an individual after verifying that he or she has met predetermined and standardized criteria” (Knapp, Fabrey, Rops, et al., 2006, p. 6). It is a process based on existing legal and psychometric requirements by which individuals who have demonstrated a specific level of knowledge or skill required by a profession are identified to the public and other stakeholders (Knapp, et al., 2006).
Certification programs evaluate professionals against an established industry standard set through a defensible process (often called a job task analysis or role delineation process) resulting in the establishment of appropriate benchmarks of required knowledge and skills (Wright, Turnbeaugh, Weldon, et al., 2015). Certification is awarded for a specific duration with required continuing professional development reported on a set cycle (Wright, et al., 2015). If a certificant does not fulfill the required maintenance activities, the certification award expires.
The entire industry of PPE against the thermal hazard of an electric arc has existed for 20 years. However, gaps still exist in electric arc knowledge and standardization. This three-article series provides a broad overview of today’s state of the art for electrical workers’ protection against electric arc thermal hazard.
Part 1 of the series identifies key factors for future progress, and discusses electric arc classification, properties, behavior and methods of thermal energy dissipation.
Statistical trends in general electric and electric-arc- related fatalities and trauma are essential for future improvements. However, information on electric arc incidents is hard to find in government statistical reviews. Part 2 of the series is dedicated to reviewing statistical data and identifying gaps in reporting electric-arc-related incidents and corresponding skin burn trauma. The authors also review previously published electric arc incidents.
Part 3 of the series discusses multiple elements for reliable protection against electric arc. These include arc hazard assessment, standardization for PPE test method requirements, results of the latest research, challenges and suggestions.
Factors for PPE Progress
Fire Retardant Materials
During the past 15 years, revolutionary changes occurred in the availability of different fabrics and materials for PPE used by electrical workers to protect against the thermal effect of an electric arc during live electrical work. Removing flammable and melting materials and fabrics from the face, body and hands was a major factor in reducing burn incidents.
An evolution is underway in how OSH professionals practice. Looking back about 10 years, many of the profession’s thought leaders began to postulate that the compliance-based approach to developing workplace safety programs had run out of steam, so to speak. This thinking was based, in part, on data that showed a slowing in the reduction of fatalities. In some categories and years, the data also showed an increase in serious injuries (those that result in permanent disability or long periods off work) (BLS, 2016).
This introspection also stemmed, in part, from the fairly common occurrence of large organizations with large OSH budgets maintaining low, very low or zero incident rates for less-serious injuries (i.e., OSHA recordables), yet still experiencing multiple fatalities or significant catastrophes (i.e., serious injuries to multiple people or significant property damage). In-depth investigations of these catastrophes conducted by outside panels revealed significant flaws in the implementation of safety programs that had been well-regarded within the organization, the safety community and third-party reviews. The reports often identified substantial and repeated warning signs of imminent catastrophe that were often ignored or not given the level of seriousness they deserved (CSB, 2015; 2016; NASA, 2003).
Further, investigation revealed that significant incidents in organizations large and small were often directly caused by a failure to control obvious hazards or use standard safety practices (e.g., tying off while working at heights, using lockout/tagout when servicing machinery, failing to use protective systems in excavations) (Manuele, 2008).
The surge in use of electronic cigarettes (e-cigarettes or e-cigs) has raised many questions for OSH professionals as to whether use of such products should be allowed in the workplace. After all, if these are smoking-cessation devices, should we not encourage employees to quit smoking through use of these devices? What is the harm? Is it not just water vapor? E-cigarettes were originally designed in 1963 by Herbert Gilbert and patented in 1965 as a smokeless nontobacco cigarette intended to provide a harmless means of smoking (U.S. Patent No. 3,200,819 A, 1965). Researchers estimated some 460 different brands and more than 7,700 unique flavors were on the market as of January 2014 (Zhu, Sun, Bonnevie, et al., 2014), and the numbers have likely increased since. U.S. e-cigarette sales were estimated at $2.2 billion in 2014 (Rigotti, 2015) with an expected annual growth of more than 50% for the foreseeable future (Mickle, 2015).
While configurations of these devices have evolved through many generations, the typical components include a fluid-filled reservoir, which contains the liquid e-fluid or e-juice to be vaporized, an atomizer (heating coil) to vaporize the liquid and a battery (typically lithium) to power the atomizer. First-generation e-cigarettes resemble traditional cigarettes; second-generation devices have a distinct reservoir tank and larger battery; third-generation e-cigarettes are fully modifiable by the user, often to increase vaping power, output and battery life (Floyd, Aryal, Wang, et al., 2017). The intent is for users to inhale nicotine or flavored vapors without the cancer risks associated with traditional tobacco cigarette use because the devices have no combustion source or tobacco, which forms cancer-causing by-products when burned, (Maron, 2014).
In highly hazardous chemical process facilities, it is critical to bridge workforce hazard recognition knowledge and competency for process safety and OSH. This is important for four reasons:
This article focuses on the needs of workers who must deal with both process and occupational hazards in highly hazardous chemical processing facilities. It uses both operators and maintenance workers to represent this industry’s overall workers due to their hands-on physical work activities.
To help understand the differences and similarities of process safety and OSH, the following scenario is used for reference throughout the article.