Hazard Studies and Risk Assessment

It is the professional responsibility of all designers of process plant to consider the impact of their work on people, organisations and societies affected by their designs. 

In its Rules of Professional Conduct and Disciplinary Regulations Issue III 7 December 2001, The Institution of Chemical Engineers defines these responsibilities for its members  

In this chapter we shall be looking at techniques which can be used by designers to help them recognise these issues and design plants and 

The approach in this chapter is aimed primarily at the chemical process industries, but the ideas may be broadened and modified to cover many diverse situations. 

Although some of the words used above have an intuitive, if slightly fuzzy meaning, we need to be fairly precise about their definitions in the context of Hazard Studies and Risk Assessment. 

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Last, but not least, safety is considered in terms of the analysis of the risks associated with potential hazards identified by detailed consideration of the proposed process flowsheet. Safety is the number one concern for chemical engineers and the reader should not confuse the fact that it is the focus of the final chapter in this book with its order of importance. However, in order to carry out a hazard study and risk assessment, one must understand the concepts on which a process flowsheet is developed, and these are covered in the preceding chapters. The procedure describe in Chapter 10 is recognised as best practice in the process industry sector. 

Hazards identification and risk assessment studies can be performed at any stage during the initial design or ongoing operation of a process. If the study is performed with the initial design, it should be done as soon as possible. This enables modifications to be easily incorporated into the final design. 

USAEC. (1975) Reactor Safety Study, WASH-1400 (United States Atomic Energy Commission). Wells, G. L. (1980) Safety in Process Plant Design (Institution of Chemical Engineers). Wells, G. L. (1996) Hazard Identification and Risk Assessment (Institution of Chemical Engineers). 

Several animal models have been developed to study mechanisms of respiratory allergic responses to proteins and chemicals. However, only a few of these have been used as predictive tests in hazard identification and risk assessment. These models have employed guinea pigs, mice or rats. This report describes guinea pig models developed as predictive tests for risk assessment of proteins and LMW chemicals as respiratory allergens. 

Contents indude fundamentals of hazard, exposure, and risk assessment concepts in risk assessment risk rtssessment process techniques and methods of approach hazardous waste management decisions from risk assessment and selected case studies. Five appendices are included with information on carcinogens, terms and equations, and other pertinent information for risk assessments. 

These examples above demonstrate yet another area of uncertainty in the extrapolation of animal toxicity studies to the hazard identification and risk assessment of humans. Since the data base in this area is extremely limited, particularly at chemical concentrations which are environmentally realistic, major endeavours in this area are urgently needed. 

All employed dryers must be equipped with clear and comprehensive operating manuals prepared jointly by the equipment supplier and the plant operating management. The manual should be learned by the operators, who are to be trained in recognition of hazardous situations and risk assessment with the material being dried. Very useful techniques, known as Hazop (hazard and operability studies) and Kazan (hazard analysis), may be applied successfully in both new and existing processing plants [39,40]. 

Wells G (1996) Hazard identification and risk assessment. IchemE, Rugby lEC 61882 Ed. 1.0 b 2001 (2001) Hazard and operability studies (HAZOP studies) application guide, Edition 1.0, International Electrotechnical Commission Das PAAG-Verfahren, IVSS Genf 2000... 

Tbxicology of Chemicals, and a collaborative partnership between Environmental Defense and DuPont (Oberdorster et al., 2005b Warheit et al., 2007b Environmental Defense and EhiPont, 2007). These frameworks provide guidance for studies that may be necessary for conducting future hazard evaluations and risk assessments of nanomaterials. 

Hazard identification a process to identify hazards and associated risk to persons, property, and structures and to improve protection from natural and human-caused hazards Hazard Identification and Risk Assessment (HIRA) a process to identify hazards and associated risk to persons, property, and structures and to improve protection from natural and human-caused hazards HIRA serves as a foundation for planning, resource management, capability development, public education, and training and exercises Hazard operability study a structured means of evaluating a complex process to find problems associated with operability or safety of the process Hazard rating (NFPA) classification system that uses a four-color diamond to communicate health, flammability, reactivity, and speciflc hazard information for a chemical substance a numbering system that rates hazards from zero (lowest) to four (highest)... 

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