Elimination hazards

In attempts to reduce toxic hazards, eliminate homogeneous prereactions, lower deposition temperatures, and use cheaper precursors there have been considerable efforts directed toward the development of alternative precursors for use in MOCVD.10 Another approach to using intrinsically less reactive compounds is to use a single-molecule (or single-source ) precursor, in which all the elements required in the film are present in the one molecular species. The compounds potentially exhibit many or all of the following advantages over conventional MOCVD precursors ... 

Industrial fire protection and safety engineers attempt to eliminate hazards at their source or to reduce their intensity with protective systems. Hazard elimination may typically require the use of alternative and less toxic materials, changes in the process, spacing or guarding, improved ventilation or, spill control or inventory reduction measures, fire and explosion protective measures - both active and passive mechanisms, protective clothing, etc. The level or protection is dependent on the risk prevalent at the facility versus the cost to implement safety measures. 

Safety- or health-hazard elimination, as in collection of siliceous and metallic dusts around grinding and drilling equipment and in some metallurgical operations and flour dusts from milling or bagging operations... 

Solvents are often the largest sources of wastes in chemical syntheses and processes. Eliminating the use of solvents can dramatically reduce the amount of waste and volatile organic compound (VOC) emissions that are produced in a process. Many solvents are themselves toxic, flammable, and explosive. Eliminating their use reduces safety and storage hazards. Eliminating the need to purchase and then treat large amounts of solvent may also provide substantial economic benefits. 

Having identified a hazard there is a hierarchy in the controls that can be put in place to deal with the hazards. Starting with the preferred option of hazard elimination the list is as follows ... 

The source of electrical hazards. Eliminate electric sparks and charge buildup replace electrical with pneumatic instrumentation, replace electric-driven with steam-driven devices. Eliminate charge buildup by increasing conductance, e.g., increasing the conductivity of the atmosphere (via ionization) and increasing the conductivity of nonconductors (by humidification or additives). 

The most effective method of avoiding accidents is through intrinsic safety. For a piece of equipment to be intrinsically safesafety has been built into the design of the equipment and is not an add-on function. Intrinsic safety can be achieved by (1) eliminating the hazard entirely or (2) limiting the hazard to a level below which it can do no harm. Under either condition, no possible accident can result from the hazard in question. Hazard elimination... 

A hazard is defined as the potential source of harm (3.5). Hazards include both the characteristics of things and the actions or inactions of people. Identifying hazardous human error potential, as well as the physical aspects of hazards, is an important part of the hazard identification process. All risks with which safety practitioners deal derive from hazards. There are no exceptions. For any particular hazard, the first and best approach is to eliminate the hazard. If there are no potentials for harm, there are no hazards. If there are no hazards, there are no risks. Hazards eliminated result in zero risk from those hazards. But, it is not possible to eliminate all hazards. 

If the hazards are eliminated in the design and redesign processes, risks that derive from those hazards are also eliminated. If there are no hazards, there is no potential for harm and, thereby, no risk. Obviously, hazard elimination is the most effective way to eliminate risk. 

The presence of dust can cause serious problems in many dry cleaning plants and in the pretreatment sections of wet cleaning plants. In addition, dust containment is an integral part of aU thermal drying units. The need for dust collection arises because of air pollution control, safety- and health-hazard elimination, and reduction of equipment maintenance costs. 

As Stated previously, system safety developed or evolved as a direct result of a need to ensure, to the greatest extent possible, reliability in the safe operation of a system or set of systems (especially when a given system is known to be hazardous in nature). While no system can be considered completely or 100% reliable, system safety is an attempt to get as close as practical to this goal. Over the years, numerous techniques and methods used to formally accomplish the system safety task have also evolved and have further expanded our capabilities to examine systems, identify hazards, eliminate or control them, and reduce risk to an acceptable level in the operation of that system. These analytical methods and/or techniques are known by many names such as— but certainly not limited to—the following common system safety tools ... 

Simply stated, the O SHA encompasses an analytical review of the controlling documents to ensure hazard elimination or control and concentrates heavily on the performance of people (human factors and human behaviors) and their relationship to the hazards within the task. The focus is primarily on the maintenance and operation of the system, rather than the system components themselves. 

Inherent hazards, eliminated by design, make the AP600 inherently safe with respect to these hazards. The AP600 has some inherently safe characteristics -- the negative reactivity coeffident at all times which halts the chain reaction in the event of an expected power increase, the large water inventory, and the provision to limit any release from the containment by placing... 

Obviously, hazard elimination or reduction is the most effective way to remove or reduce risk. If a hazard is eliminated or reduced, the need to rely on worker behavior to avoid risk is diminished. 

Basic solutions for reduction of noise hazards Elimination or substitution... 

Inherently safer plant uses basic design measures to achieve hazard elimination, prevention and reduction. The classic definition of an inherently safe plant or activity is one that cannot under any circumstances cause harm to people or the environment. This may be because ... 

Statistical summaries of all routine inspections are prepared, charted, and distributed to management and employees to show status and progress of hazard elimination. 

The primary philosophy is to follow the principles of inherent safety. This implies a systematic effort to apply the principles of hazard elimination, minimization/ intensification, hazard substitution, moderation/attenuation, and simplification. However, additional controls will still be required to control a hazardous situation, prevent escalation, and mitigate the risk to people, to the environment, asset, and reputation. Preferably, these safeguards will be passive- or active-engineered controls rather than administrative controls (i.e., dependent on direct human intervention). 

Once all the data have been evaluated and the PHA worksheet is completed, a formal report should be written documenting the results of the analysis. The narrative report typically includes a summary of all significant findings associated with operational risk. Recommendations for hazard elimination/control are also included in the report as well as suggestions for follow-on analyses. Although not entirely necessary, depending on the nature of the operation, process, or system, it is also useful to include a brief description of the project itself, its purpose and/or function as it relates to overall operations. The PHA/PHL worksheets are usually provided in the report as backup data to verify the report contents. Finally, the PHA report should also include a brief discussion of the methods used to develop the analysis (ETBA, FMEA, checklists, matrices, etc.), so that the reader can validate the report data, if required (Stephenson 1991). 

Hazard Analysis of Significant Changes Hazard analysis of significant changes, including but not limited to nonroutine tasks (such as those performed less than once a year), new processes, materials, equipment and facilities must be conducted to identify uncontrolled hazards prior to the activity or use and must lead to hazard elimination or control. If a nonroutine or new task is eventually... 

This chapter addresses these subjects. With that knowledge, safety professionals can more effectively draft their hazard elimination, reduction, and control proposals, emphasizing their significance and the possible impact on improving productivity and cost efficiency. 

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