Risk assessment elements

It is important to clearly describe and quantitatively estimate the assumptions and uncertainties involved in the evaluation, where possible. Examples include natural variability in ecological characteristics and responses and uncertainties in the test system and extrapolations. The description and analysis of uncertainty in characterization of ecological effects are combined with uncertainty analyses for the other ecological risk assessment elements during risk characterization. 

That the risk assessment has been carried out, reviewed at appropriate intervals and adequately documented. This is, in effect, a check on the operation of the risk assessment element of the Safety Management System and, where weaknesses are identified, suitable corrective action should be instigated. 

That the estimates of likelihood and severity on which the risk calculation was based were realistic, given the information available at the time. Again, this is a check on the risk assessment element of the Safety Management System but it is checking how well the risk assessment was carried out, not just whether it was carried out. 

Next, we review the eosts of quality that typieally exist in a manufaeturing business, and how these are related to the way produets fail in serviee. The remainder of the ehapter diseusses the important elements of risk assessment as a basis for design. This puts in eontext the work on designing for quality and reliability, whieh are the main topies of the book. 

Many designers consider risk assessment to be an intuitive element of their work. ITowever, a formal process model that makes risks explicit, and stresses accountability, can only be an advantage. 

FIGURE 5.32 Elements of risk assessment and risk management. (used with permission.)... 

At present the approach to assessing the potential risks of exposure to a chemical in the diet involves the application of a standardised risk assessment approach consisting of three main elements - hazard identification and characterisation and exposure assessment. 

Envlroiunental testing Is a critical element In this process since It enables the qualitative and quantitative determination of toxic chemicals In the environment and the definition of environmental pathways which may lead to human exposure This paper briefly reviews the overall process of health risk assessments and the particular role which environmental testing plays Recent efforts to assess environmental health risks In relation to Love Canal Illustrate both the usefulness and the limitations of environmental testing In risk assessment ... 

Professor Martel s book addresses specifically some of the more technical eispects of the risk assessment process, mainly in the areas of hazard identification, and of the consequence/effect analysis elements, of the overall analysis whilst where appropriate setting these aspects in the wider context. The book brings together a substantial corpus of information, drawn from a number of sources, about the toxic, flammable and explosive properties and effect (ie harm) characteristics of a wide range of chemical substances likely to be found in industry eind in the laboratory, and also addresses a spectrum of dangerous reactions of, or between, such substances which may be encountered. This approach follows the classical methodology and procedures of hazard identification, analysing material properties eind... 

The risk assessment process has the capacity to dimension, to rank, to focus and to test the sensitivities, the interdependence and the interactive responses of all these component elements. 

U.S. EPA may list a waste as hazardous for any and all of the above reasons. The majority of listed wastes fall into the toxic waste category. To decide if a waste should be a toxic listed waste, U.S. EPA first determines whether it typically contains harmful chemical constituents. An appendix to RCRA contains a list of chemical compounds or elements that scientific studies have shown to have toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other life forms. If a waste contains chemical constituents found on the appendix list, U.S. EPA then evaluates 11 other factors to determine if the wastestream is likely to pose a threat in the absence of special restrictions on its handling. These additional considerations include a risk assessment and study of past cases of damage caused by the waste. 

Exposure assessments have become an essential element of contemporary risk assessment (NAS/NRC, 1983). The primary purpose of exposure assessment is to qualitatively and/or quantitatively determine exposure and absorbed dose associated with a particular use practice or human activity. Contemporary exposure assessors and risk managers place a high premium on accurate data obtained by monitoring chemical exposure scenarios and critical human activities or work tasks. 

Table 3 describes the main parts of an environmental risk assessment (ERA) that are based on the two major elements characterisation of exposure and characterisation of effects [27, 51]. ERA uses a combination of exposure and effects data as a basis for assessing the likelihood and severity of adverse effects (risks) and feeds this into the decision-making process for managing risks. The process of assessing risk ranges from the simple calculation of hazard ratios to complex utilisation of probabilistic methods based on models and/or measured data sets. Setting of thresholds such as EQS and quality norms (QN) [27] relies primarily on... 

The link between the ecological/ecotoxicological risk assessment and the risk management frameworks is demonstrated. The ecological risk assessment consists of seven interactive elements (Fig. 17). The quantitative and descriptive science used to conduct ERA (Table 5) does not answer, in a direct way, the question of what should be done to manage the risk. Science determines adversity, but the public determines acceptability (Fig. 18). But acceptable risk is a highly subjective and relative term. It is time and space-specific and depends upon definitions of quality of life and robustness of the environment. 

Scope of the CLL approach. Critical loads and levels can be calculated for various specified sensitive elements of the environment (UNECE CLRTAP 2004, V-l). However, terrestrial and aquatic ecosystems are most frequently referred to as receptors in this effect-based approach. In addition, specific parts of ecosystems (e.g., populations of most valuable species) or ecosystem characteristics can be defined as receptors as well (UNECE CLRTAP, 2004). Such flexibility and established provisions for ecosystem assessment makes the CLL concept a promising solution for ecosystem risk assessment and a potential substitute for site-specific chemical RA following the bottom-up approach. 

Thus, one should mention that the quantitative estimates of various links of biogeochemical cycles of elements and their interactions are of crucial importance for environmental risk assessment for the given ecosystems under anthropogenic pressure. 

SVA Methodologies There are several SVA techniques and methods available to the industry, all of which share common elements. The following is a list of some available SVA methodologies published by various governments, private, and trade andprofessional organizations. Some are merely chapters or sections of documents that address security or risk assessment/risk management in broader terms. Some are SVA or VA publications by themselves. Some of these methods are complete, systematic analytical techniques, and others are mere checklists. 

Risk Assessment Technical Guidance Document (a. 16), which will presumably apply to registration under REACH. The adequacy of each test can be defined by two basic elements ... 

This voluntary risk assessment programme started in 1995 and concerned a list of 25 chemicals dichloromethane, chloroform, tetrachloromethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, vinyl chloride, trichloroethene, tetra-chloroethene, hexachlorobutadiene, monochlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, tetrachlorobenzene, hexachlorobenzene, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, pentachlorophenol, hexachloro-cyclohexane, dioxins, PCB, DDT, and elemental mercury. 

The remaining parts of this chapter will provide detailed information about each of these six steps. However, specific strategies for risk assessment and management may need additional elements, depending on the nature of the hazard, the foods in which it may occur and other specific conditions. For example, some additives may also occur as natural constituents in the diet or may be chemically altered when they come into contact with food components. For such substances a unique approach may need to be developed. 

Understanding fire hazards is essential to risk reduction and fire protection decision-making. A fire hazard analysis (FHA) is a tool used to understand fire hazards. The process of quantifying the fire hazard is typically motivated by the need to determine the overall hazard of a process or facility or to have a decision-making tool for fire protection systems (Chapter 6). An FHA is an important element of a risk assessment and can also be used as a stand-alone hazard evaluation tool. 

Development and application of a standard for good assessment practice The quality of risk assessments and risk management information could become an element of competition in the global market. To this end an anditable and internationally recognised standard is reqnired. 

The systematic evaluation of substance properties and predictable or actual exposure patterns over the entire life-time of a substance within the scope of risk assessment is as yet a relatively recent instrument, for which harmonised scientific rales were created in the EU for the first time in 1997 in the form of the Technical Guidance Documents (TGD). An essential element in this range of instruments is how to deal with shortcomings in knowledge. Wherever information is missing, standardised worst-case scenarios are conceived taking into account appropriate safety factors . If under these worst-case assumptions a rele-... 

In order to reduce animal testing under REACH, and also because of the ban on the marketing of cosmetic products/ingredients tested on animals, a broader strategy for risk assessment has been suggested. One element suggested in this strategy is the TTC concept. 

The Handbook also pointed out that risk characterization does not stand alone, as it is one of the four steps in risk assessment. There is only a single technical characterization of risk as a final product of the risk assessment. This technical characterization must be written with enough detailed technical information to allow another expert (e.g., other risk assessors, peer reviewers) to reasonably reconstruct what was done in the risk assessment, including to be able to identify the assumptions made during the risk assessment. Since the risk characterization is a part of the risk assessment itself, it should be kept in mind that the goal of the risk characterization is not to repeat the entire risk assessment, but just to identify the key elements from the risk assessment that really make a difference in its outcome. 

The major elements to be considered in the risk characterization part include key information, context, sensitive subpopulations, scientific assumptions, policy choices, variability, uncertainty, bias and perspective, strengths and weaknesses, key conclusions, alternatives considered, and research needs. Whether every element is actually written into the risk characterization or not, depends upon the purpose of the risk assessment and the detail necessary to adequately characterize it. By the time the risk assessment is completed, the universe of policy choices, management decisions, and uncertainties should have been identified, as well as the conclusions of the risk assessment. Because key findings differ for each risk assessment, it is not possible to define exactly what they are genericaUy. Professional judgment is necessary to define them. 

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