Accident process, nature

This paper is a review of methods for estimating releases of chemicals into the environment in the course of extraction of raw materials, manufacturing, use, storage, transportation, and disposal, as well as by accidents or natural processes. It discusses source types, forms of substances released (solids, liquids, and gases), receiving media (air, water, soil), time pattern of release (continuous versus intermittent, cyclic versus random), and geographic patterns of release (point, line, area, and volume sources). 

The fetus receives estrogen and progesterone in considerable quantity from the placenta for example, Zander (Zl) has estimated that approximately the same amount of progesterone goes to the fetus as to the mother. It is not known whether this large dose of potent hormone is received by the fetus by design and is required for essential purposes, or whether by an accident of nature the hormones are received in such large amounts as to necessitate the development of special processes for detoxication. Whatever the reason, steroid metabolism in the fetus is very different from that in the adult, and some of the differences persist up to 4 years after birth (B3). 

The results of analyses are the calculated plant parameters — both global (MCC) and local (individual fuel channels) — determined as a function of time. There are some key parameters that are of interest as they reflect the nature and complexity of the accident process. This set of parameters to be identified in each particular case should allow for ... 

The mining facility consists of four major operations 1) mining, ore extraction and transportation, 2) ore processing - treatment with chemical solvents to remove minerals, 3) removing impurities and 4) utilities e.g., electricity, steam, water, air and natural gas provided by the facility s power plant and by off-site suppliers. Accidents in any of these operations can stop the whole process. 

The successes of the traditional approach have largely been obtained in the area of occupational safety, where statistical evidence is readily available concerning the incidence of injuries to individuals in areas such as tripping and falling accidents. Such accidents are amenable to behavior modification approaches because the behaviors that give rise to the accident are under the direct control of the individual and are easily predictable. In addition, the nature of the hazard is also usually predictable and hence the behavior required to avoid accidents can be specified explicitly. For example, entry to enclosed spaces, breaking-open process lines, and lifting heavy objects are known to be potentially hazardous activities for which safe methods of work... 

The proper handling of chemicals in the process is critical for accident prevention. The liazard potential of an operation depends on tlie nature and physical state of the material. For e. aniple, accidents may result from... 

Accidents due to naturally occurring conditions resulting from the structure of tlie land or from tlie ravages of weatlier were reviewed briefly in Cluipter 5. Outdoor processing, coninion in industries using hazardous chemicals, increases... 

The first step in minimizing accidents in a chemical phuit is to evaluate the facility for potential fires, explosions, and vulnerability to other liazards, particularly those of a chemical miture. This calls for a detailed study of plant site and layout, materials, processes, operations, equipment, and training, plus an effective loss prevention program. The technical nature of industry requires detailed data and a broad range of experience. Tliis complex task, today becoming the most important in plant design, is facilitated by the safety codes, standiu ds, and practice information available. The technical approach to evaluating die consequences of hazards is discussed later in tliis cliapter and in Part V (Chapters 20 and 21). 

The what-if/checklist analysis method combines the creative, brainstorming features of the what-if analysis with the systematic features of the checklist analysis. The PrHA team uses the what-if analysis method to brainstorm the types of accidents that can occur within a process. Then the team uses one or more checklists to help fill in any gaps. Finally, the team members suggest ways for reducing the risk of operating the process. The what-if analysis encourages the PrHA team to consider potential accident events and consequences that are beyond the experience of the authors of a good checklist and, thus, are not covered on the checklist. Conversely, the checklist lends a systematic nature to the what-if analysis. 

Other, often made distinction in types of research, are between exploration, description, explanation, and testing, van der Zwaan (Zwaan van der, 1990). Exploration is conducted when theoretical knowledge in literature lacks information on which variables are important. Description types of research aim at the relevance of the variables. Explanation types of research aim at identifying the causal links between variables and phenomena. Finally, testing types of research aim at proving the hypotheses derived from the causal links. The research project discussed in this thesis is mainly explorative in nature. The emphasis is to design concepts and a protocol, which increases the understanding of the problem of how and why accidents continue to occur in companies in the chemical process industry. In this way a contribution to the solution of the problem will be made and consequently this research can be typified as applied positivistic exploratory research. 

Therefore, in this chapter we describe major refinery operations and the products therefrom and focus on their composition, properties, and uses. This presents to the reader the essence of petroleum processes, the types of feedstocks employed, and the product produced, as well as warning of the types of the chemicals that can be released to the environment when an accident occurs. Being forewarned offers an environmental analyst the ability to design the necessary test methods to examine the chemical(s) released. It offers environmental scientists and engineers the ability to start forming opinions and predictions about the nature of the chemical(s) released, the potential effects of the chemical(s) on the environment, and the possible methods of cleanup. 

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