Patty's Industrial Hygiene, Hazard Recognition. Группа авторов
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Название: Patty's Industrial Hygiene, Hazard Recognition
Автор: Группа авторов
Издательство: John Wiley & Sons Limited
Жанр: Химия
isbn: 9781119816188
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As risk communication challenges have been identified for the most common EHS professions, we are now positioned to assist field practitioners and generalists alike to identify strategies and processes to help them address work‐related risk issues as they arise. Models of occupational risk prevention are derived primarily from the safety profession and they are essential for understanding the causal pathway of accidents and incidents across EHS. These models will describe which data are relevant to collect and assist in focusing the design of risk assessments to maximize the collection of risk communication components. Together with insight into the context of the events occurring, these data can, therefore, be transformed into information, and with the aid of models, information can be turned into knowledge. This derived knowledge can then be transferred into clearly delineating the value of necessary interventions, outcomes, and acquiring the resources to ensure they remain sustainable. Knowledge on causal pathways of accidents and incidents not only provides insight in reasons why they occur but also directs efforts to prevent work‐related adverse outcomes from occurring. The scientific field dealing with occupational risk prevention, however, is relatively young, and the models used in this field of research have a status of graphic presentations, instead of a classic scientific model (10).
3.1 Bow‐Tie Model
EHS professionals can learn a lot in improving risk communication from the safety bow‐tie model for presenting accidents (Figure 1). In the bow‐tie model, barriers are depicted that prevent the scenario from unrolling. These barriers are the center of a safety management system. Managing these barriers is the key to successfully manage safety. The barriers on the left side of the bow‐tie are called primary barriers. Failing primary barriers can lead to a central event and can consist of failing hardware barriers or inadequate human interventions 11, 12). Supporting these primary barriers are the underlying management factors, which by failing cannot generate a central event, but determine the quality of the primary barriers. For safety, risk prevention, or exposure elimination, it is necessary to stay left of the red circle representing the central event of an accident.
Figure 1 Bow‐tie model.
Therefore, the bow‐tie is a combination of a fault tree and an event tree, linked together by a “central event.” The central event in (Figure 1 presents a state of “loss of control”; the energy content of the hazard is released and the barriers on the right side are in place to prevent the released energy from becoming an unwanted consequence like an injury or accident. As the bow‐tie was initially developed as a model for safety science, hazards like electricity or falls from heights can clearly assist in how the bow‐tie acts as an excellent risk communication model. Left‐side barriers like training and control barriers like Lock‐Out/Tag‐Out or the right fuses to prevent electrical shocks and guard rails, parapets, or the right ladder can help avoid falls from elevation. If any of these barriers fail, the release of the central event's energy does not necessarily need to lead directly to the consequences of an accident. Right‐side barriers like GFCI or surge protectors can halt the flow of electricity into a worker and fall protection devices can reduce or eliminate the adverse outcome initiated by the initial fall from elevated surfaces. Generally, scenarios leading to consequences can occur within seconds or even less. The left side of the bowtie reflects the latent condition, which can take much more time to develop, sometimes up to several years 13).
This way of presenting accidents, certainly those that lead to severe outcomes, has a major advantage for risk communications. The presentation focuses risk prevention activities for central events. Companies can pay their attention to central events they would like to avoid most, either guided by past experience, industry‐related occurrence statistics or guided by the notion that some central events will jeopardize their production. However, it is astonishing to see that most companies only have vague ideas on central events they need to avoid. Finally, the bow‐tie presentation has scenarios as its main component, either for major or for minor accidents and incidents. This difference between different types of incidents is important. It is a common belief that minor and major accidents share the same causes, or accident scenarios, and their consequences are largely governed by chance.
3.2 Multidisciplinary Bow‐Tie Model
Although the bow‐tie model is derived primarily from the safety profession and is designed for use by OS disciplines, it is also an excellent tool for use within and between EHS professionals.
Prevention can be seen in Figure 2 on the left side, serving as the barriers that seek to be appropriately placed to avoid a given hazard from becoming an unwanted central event. Although these barriers may differ across the EHS professions to achieve this prevention, they may also work in concert with one another or create new risks that require the consideration of additional barriers. Using a task with a high hazard chemical as an example, an IH may require the use of a glove box as a control barrier to eliminate potential exposures. An EA would now need to consider the hood's ventilation exhausting the chemical into the air and may require additional barriers to comply with local, regional, or national regulations. An OS may act more locally in considering whether the chemical's vapors may create flammability or electrical concerns inside the hood and may have barrier requirements to prevent these potential central events. Whether acting within these EHS disciplines, or acting as a singular EHS Generalist, all of these decisions will be based on potential risk. This figure clearly illustrates how communication of this risk is just as important for convincing management that investment in these barriers and their maintenance over time is necessary as it is for training workers that the proper use of these control barriers is essential.
Figure 2 Bow‐tie presented in a multidisciplinary format.
Looking at each of the EHS professions separately, this left‐side preference in (Figure 2 can also be seen in ergonomics, where the multiple strategies for controlling musculoskeletal risk factors can be seen as left‐side barriers 14, 15). However, an IH does not see work‐related risk prevention in the same manner. Chemical exposures are seen as the central event, and in most instances, their emission, the right side, is expected and full enclosure, elimination, and substitution are the only left‐side components. EAs are quite like IHs in this respect as both professions accept some level of exposure, whether to workers or the environment, as long as they are kept below regulatory limits or OELs by utilizing the barriers on both the left and right side of the central event. OPs also are more applied on the right side of the bow‐tie, perhaps even more so as they most often see patients that are experiencing signs of pending injury or illness or have already acquired adverse consequences. In fact, the OP and the services they offer can be seen as an effective right‐side barrier themselves, with medical surveillance blood draws, hearing tests, and respirator use examinations as examples. Although they are certainly key players for identifying the need for EHS expertise to assess and intervene in workplaces with identified issues, the OP's primary left‐side barrier utility is for their influence on job selection and allocation as examples of preventative actions. Therefore, when the bow‐tie is viewed as a multidisciplinary model for simplified risk communication, for the role of barriers to workers and management alike, it can be seen as a progressive process in which EHS disciplines unite to seek prevention and mitigation of unwanted work‐related injury, illness, or disease consequences (11).
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