Safety assessments disadvantages

This section is devoted to the definition and comparison of the three nonrodent animal models (dog, ferret, and monkey) in terms of experimental procedures, environmental and dietary requirements, as well as advantages and disadvantages of use in safety assessment testing. 

Advantages and Disadvantages. Advantages of using monkeys in safety assessment studies include their phylogenetic proximity, as well as their physiological, behavioral, and, often, metabolic similarities, to humans (Table 16.13). An example is the similarity between the ovarian cycle of female monkeys and women (Mazue and Richez, 1982), which makes the monkey the ideal animal model for reproductive studies. Another advantage associated with most species of monkeys used in safety assessment studies is that they are much smaller than nonrodents such as the dog and, thus like the ferret, require less test compound. 

While there are advantages and disadvantages associated with all three nonrodent species, the dog is probably the nonrodent species most frequently used in safety assessment studies. This is because dogs are relatively docile and even tempered,... 

Richei et al. (2001) introduced the Human Error Rate Assessment and Optimizing System (HEROS) to evaluate and optimize the man-machine interface in Probabihstic Safety Assessment (PSA). The authors firstly showed the major disadvantages of current HRA methods as ... 

Each of these tools has its own advantages and disadvantages and the extent to which these can be used during various phases of the product life cycle, and the degree to which it can be applied to safety assessments, vary. Listed in alphabetical order, the tools/techniques most frequently used by the author have been shaded. 

In most cases, safety monitoring wUt be the major task for a DMC. Even if the safety parameters monitored are not directly related to efficacy, a DMC might need access to unblinded efficacy information to perform a risk/benefit assessment in order to weigh possible safety disadvantages against a possible gain in efficacy. ... 

In the first stage, the EFS was eliminated to assess their importance in the overall level of safety (given the disadvantages of its use), and although there was an increase of almost 10 times the critical frequency of the final state, it was appreciated that minor modifications in valves could return the initial value of event frequency. 

It is very clear from the complexity of the situations described in the case studies of the last two chapters, that simple factors of safety, load factors, partial factors or even notional probabilities of failure can cover only a small part of a total description of the safety of a structure. In this chapter we will try to draw some general conclusions from the incidents described as well as others not discussed in any detail in this book. The conclusions will be based upon the general classification of types of failure presented in Section 7.2. Subjective assessments of the truth and importance of the checklist of parameter statements within that classification are analysed using a simple numerical scale and also using fuzzy set theory. This leads us on to a tentative method for the analysis of the safety of a structure yet to be built. The method,however, has several disadvantages which can be overcome by the use of a model based on fuzzy logic. At the end of the chapte(, the discussion of the various possible measures of uncertainty is completed. 

This approach often has the disadvantage of being a qualitative decision, based on available data and circumscribed by the experience of the participants. Written rationales are often missing, on less than adequate, for further peer or legal review. The consensus approach does, however, allow for a strong introduction of "rational" common sense, qualitative risk assessment, etc. to be introduced into the decision making process. Many of our existing health and safety environmental standards were developed on this approach. 

Risk assessments covering their common activities to which significant risks are attached. Although there is no requirement for contractors employing fewer than five people to have either a written safety policy or written risk assessments, not having done so is likely to place them at a disadvantage - references from other contractors would be useful in that case... 

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