Risk characterization process defined

The hardest part of engineering risk assessment has turned out to be the prediction of the modes of failure. Serious accidents at nuclear installations, such as those at Three Mile Island or at Chernobyl, have been caused by modes of failure that had not been analysed at all. For example, the report of the Presidents Commission on the Accident at Three Mile Island (Presidents Commission, 1979, p9) highlighted that the concentration of the assessment process on more obvious large break scenarios meant that the eventual mode of failure, which was a result of a chain of a number of more minor events, was not even considered. Despite the use of significant resources in the design process, the risk assessment had been unable to characterize the complex system adequately, a system that was totally human-made and defined. In particular, the risk assessment process had not been able to identify modes of failure caused by humans involved in the operations of the reactor behaving in unexpected ways. 

Operational risk generally is defined as risk of loss resulting from inadequate or failed internal processes, people and systems, or external events (APRA, 2007 Erickson, 2001 McCuaig, 2005 Vaughn, 2005 Walker, 2001 Wikipedia, 2007). Information technology operational risks in todays digitized pharmacy are characterized by six event factors ... 

Health risk assessment is defined as tlie process or procedure used to estimate tlie likelihood that humans or ecological systems will be adversely affected by a chemical or physical agent under a specific set of conditions. Tlie health risk evaluation process consists of four steps hazard identification, dose-response assessment or liazard assessment, exposure assessment, and risk characterization. 

Hydrophobicity (or lipophilicity) characterizes the readiness of a molecule to escape or to prefer the water environment. It plays a fundamental role in biochemical processes and influences the fate of a molecule in the environment. Thus, hydrophobic descriptors play an important role in QSAR modeling that is used in drug research and for risk characterization. The most widely used hydrophobic descriptor is the octanol-water partition coefficient (log P) proposed by Hansh [49]. P is a quotient between solubihties in octanol and water. It is defined by following equation ... 

A risk assessment is defined as a qualitative and quantitative process conducted by EPA to characterize the nature and magnitude of risks to public health from exposure to hazardous substances, pollutants, or contaminants released from specific sites. Risk assessments include the following components hazard identification, dose-response assessment, exposure assessment, and risk characterization. Statistical and biological models are used in quantitative risk... 

While risk assessment in the context of protecting public health has been performed for many years, it is the 1983 U.S. National Academy of Sciences Report (Committee on the Institutional Means for Assessment of Risks to Public Health Commission on Life Sciences National Research Council 1983) that has served as the tenet for practicing risk assessors (see Chapter 1). Risk assessment was defined as the characterization of the potential adverse health effects of human exposures to environmental hazards. The predictive aspect of risk assessment was set by the use of the word potential. A fundamental expectation of the risk assessment process was that it should attempt to accm-ately predict adverse effects before there is evidence of disease in the population. Thus, risk assessment goes beyond the mere description of epidemiological and clinical case-control studies. In that report, the committee defined logical components of a risk assessment which still serve as guiding principles today. They were and are (a) hazard assessment or the qualitative determination that a stressor poses a hazard as evidence by causal evidence of an ill effect,... 

The preceding description of LCIA alludes to risk characterization steps however, LCIA differs from risk assessment in several important respects [1]. LCIA seeks to link a system, as defined in the LCA, with potential effects in order to allow for a relative comparison of the potential impacts from alternative products or processes. LCIA is not designed to quantify accurately the risk of actual harm to an exposed population, ecosystem, or resource. 

The second objective of the hazard assessment concerns characterization of the identified hazards of a particular substance. Under REACH this means that the registrant must define so-called derived no-effect levels., abbreviated DNELs. With respect to human health, these values constitute exposure levels above which humans should not be exposed and below which risks for humans are considered controlled. The DNEL derivation is a complex process which comprises several conversion steps and the application of different assessment factors. In the case of reproductive toxicity, the registrant derives separate DNELs with respect to developmental toxicity on the one hand and to impairment of sexual function and fertility on the other hand. 

Recommendation 4-2. The Army should define the quantity and characteristics of anticipated nonprocess waste streams and evaluate options for the final disposition of each type of waste. On-site processes should be developed and demonstrated for treating all agent-contaminated wastes. Methods of representative sampling and characterization of wastes should be developed to verify that treated wastes are free of agent to below appropriate risk thresholds. 

One of the main objectives of TSCA is to characterize and evaluate the risks posed by a chemical to humans and the environment before the chemical is introduced into commerce. TSCA accomplishes this through the requirement that manufacturers perform various kinds of health and environmental testing, use quality control in their production processes, and notify EPA of information they gain on possible adverse health effects from use of their products. Under TSCA, manufacturing is defined to include importing , and thus all requirements applicable to manufacturers apply to importers as well. 

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