Risk assessment hazard seeking

PBPK models improve the pharmacokinetic extrapolation aspects of the risk assessment process, which seeks to identify the maximal (i.e., safe) levels for human exposure to chemical substances (Andersen and Krishnan 1994). PBPK models provide a scientifically sound means to predict the target tissue dose of chemicals in humans who are exposed to environmental levels (for example, levels that might occur at hazardous waste sites) based upon the results of studies where doses were higher or were administered in different species. Figure 2-4 shows a conceptualized representation of a PBPK model. 

Chapter 8 is devoted to addressing severe injury potential. It makes the case that safety professionals must undertake separate and distinct activity to seek those hazards that present the most severe injury or damage potential so that they can be given priority consideration. To do that effectively, they must be capable of making hazards analyses and risk assessments. 

Making hazards analyses and risk assessments is an art. It is not a science. Achieving absolute certainty in determining incident probability or consequence is not possible. A variation of a thought attributed to Descartes applies If you can t know the truth, you ought to seek the most probable. 

Hazard assessment begins with assembling information regarding the potential physical/chemical hazards or toxicity of a chemical. The risk assessor may seek to characterize ... 

If the model user seeks predictive estimates within a rather broad range and/or is using predictive data as but one element in a large cluster of criteria for risk assessment or risk management of a site, such as a hazardous waste site, the required level of agreement between empirical data and model outputs may not dictate very close concordance. If predictive data are being sought for some finite threshold value in permissible lead exposure or some... 

A more sophisticated approach will often be required where hazards and risks are changing frequently, as in the construction industry, and also where clients, work partners and other external organisations seek evidence of more detailed analysis than Five Steps to Risk Assessment is likely to provide. There is no shortage of more complicated commercial systems, and these are often computer-based so as to enable quick updating in changing conditions and rapid review. 

Adoption of the GALE principle means that if there are circumstances where the risk associated with a particular hazard increases, the system remains acceptable if it can be shown that risks in other areas have been reduced by an equivalent or greater amount. However, the principle does not remove the need to assess risk on a hazard by hazard basis or to seek to apply mitigation measures where reasonably practical. If a risk reduction measure can reasonably be put in place, even if it is not necessary to achieve the overall safety objective, the project is expected to consider applying this risk reduction. 

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