Risk ranking types

The current situation with regard to risk assessment in the use of a wide range of different types of flame retardant is reviewed with respect to EEC council regulation No.793/93. The countries responsible for risk assessment on particular materials are listed and tonnages of materials used are noted. Three methods of prioritisation are used based on quantity used, environmental hazard potential and environmental risk ranking. 6 refs. 

Even without quantification, it is noticeable that any type of risk analysis is very subject to the assumptions and prejudices of the persons involved. One company, for example, conducted two HAZOPs on two very similar processes, which were in the same location, were of the same age and complexity, and had were run by the same management. An outside observer would reasonably expect that the two analyses would give roughly similar results. In fact, the opposite was the case. The findings were radically different, and the risk rankings were even more differentiated. 

Semi-quantitative techniques, consisting of index and matrix methods. Examples are Dow Fire and Explosion Index, Mond Index, and Pipeline Index for risk ranking of different facilities of the same type, and the matrix method for risk ranking of potential hazardous events that a given facility or organization can face. 

This analysis involves the identification and evaluation of risks by type and impact (i.e. maximum potential loss) on the company. A further analysis - Risk Ranking - may then be undertaken. 

Different types of risk ranking. (A) Risk ranking as per organisation structure, (B) risk ranking as per risk category (type). 

As the first step of determining fire load, the initial fire risk assessment is performed to assign risk ranking to potential cases by combining leak frequency, ignition probability, segment inventories and fire types. Representative cases with the highest potential risk are selected for further detailed consequence analysis. 

Go to the Web and develop a list of suppliers along with unit costs for some of the various types of flocculants described in this chapter. Also obtain the MSDS (Material Safety Data Sheets) for these chemicals. Once you have collected the information, develop a relative ranking of unit cost and health risk associated with each. For question 2 you will need information of recommended doses. 

The amount and type of hazards will determine the performance standard specified in site-specific control plans. This includes the content, detail, and formality of review. The approval of the plans is based on risk and hazard potential. Using the hazard-based approach, levels of risk or methods to rank risk (degree) are standardized. 

No problems rank high in all four types of risk, or relatively low in all four... 

As Hendershot (1995) has pointed out, most process options will be inherently safer with respect to one type of hazard, but may be less safe from a different viewpoint. In some cases the overall balance is readily apparent and it is easy to get general agreement on which option offers the safest overall balance. In other cases that balance is less apparent, and more sophisticated tools including qualitative ranking schemes, quantitative risk analysis and formal decision making tools may be needed. 

Careful attention must be given to assessing causality. Causation also can be ranked in terms of weight of evidence (Jekel et al. 1996). Greater weight is given to a sufficient cause that, when present, always results in disease. Next, a necessary cause also precedes disease and, when absent, cannot result in disease. The third and weakest type of causation is a risk factor that when present, increases the likelihood of an outcome in exposed versus unexposed individuals. A risk factor is neither a necessary nor a sufficient cause of death or adverse health outcome. Most observational studies estimate risk factors in assessing causality. Necessary and sufficient causes are often useful for the study of infectious diseases. 

No problems rank high in all four types of risk, or relatively low in all four Problems that rank rclati cl> high in tluee of the four types, or at least medium in all four, include criteria air polluUuits, stratospheric ozone depletion, pesticide residues on food, and other pesticide risks (runoff and air deposition of pesticides)... 

Rank integration. Integration (through overlap) of the possible combinations of the two sources and two habitat types which can influence the risk of impacted assessment endpoints (impact 1 and impact 2). 

The purpose of this study was to evaluate laboratory formaldehyde release test methods for predicting real-life formaldehyde air concentrations human exposure levels, and health risk. Three test methods were investigated the European perforator test, the gas analysis method at 60 C and 3% RH, and the gas analysis method at 23 C and 55% RH. Different types of particleboard bonded with urea-formaldehyde and urea-melamine-formaldehyde resins were tested. The results were used to rank boards as a function of test method, conditioning, short-term humidity, and temperature variations during storage. Additional experiments were conducted in small experimental houses at a Dutch research institute. Our conclusions are that relative ranking of products is influenced by the test method and by change in relative humidity. The relationship between test method and release in real-life situations is not clear. In fact, it seems impossible to use laboratory measurements to predict real-life product performance of board if the board is not fully in equilibrium with the atmosphere. 

Typical types. An international ranking of HPV types that put women at high risk of cervical cancer shows that the six most common ones account for nearly 90% of the cases. The Merck and GSK vaccines, now in efficacy trials, both contain HPV 16 and 18, the two most responsible for causing cervical cancer. (Reprinted by permission of Science Magazine from High Hopes and Dilemmas for a Cervical Cancer Vacane by Jon Cohen, 308, 621 [2005].)... 

Multiple-attribute utility theory (Keeney and Raiffa 1976) has been designed to facilitate comparison and ranking of alternatives with many attributes or characteristics. The relevant attributes are identified and structured and a weight or relative utility is assigned by the decision maker to each basic attribute. The attribute measurements for each alternative are used to compute an overall worth or utility for each alternative. Multiple attribute utility theory allows for various types of worth structures and for the explicit recognition and incorporation of the decision maker s attitude towards risk in the utility computation. 

The different types of bonds in the European market reflect the different types of issuers and their respective requirements. Some bonds are safer investments than others. The advantage of bonds to an investor is that they represent a fixed source of current income, with an assurance of repayment of the loan on maturity. Bonds issued by developed country governments are deemed to be guaranteed investments in that the final repayment is virtually certain. For a corporate bond, in the event of default of the issuing entity, bondholders rank above shareholders for compensation payments. There is lower risk associated with bonds compared to shares as an investment, and therefore almost invariably a lower return in the long term. 

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