The risk assessment procedure

An exercise comprising individual statements, some describing everyday events and others more unusual, designed to increase participants awareness and understanding of the risk assessment procedure, both for themselves and others. 

Risk characterization is the last step in the risk assessment procedure. It is the quantitative or semi-quantitative estimation, including uncertainties, of frequency and severity of known or potential adverse health effects in a given population based on the previous steps. Risk characterization is the step that integrates information on hazard and exposure to estimate the magnitude of a risk. Comparison of the numerical output of hazard characterization with the estimated intake will give an indication of whether the estimated intake is a health concern. ... 

The risk assessment procedures for the CSR will certainly be based on the current procedures, although it would be useful if the ECA software simplified them to help registrants. 

ECETOC (2004) has proposed a concept of generic threshold values based on hazard categories primarily intended to be used in the risk assessment procedure of industrial chemicals within REACH. The hazard categories are based on EU classihcation limits and for each substance to be risk assessed, inclusion in hazard categories depends on the substance s specific classification (or no classification) according to the Commission Directive 67/548/EC (EC 1967). Three hazard categories have been suggested ... 

A WHO/IPCS (2005) Harmonization Project Document has proposed using chemical-specific toxicological data instead of default assessment factors, when possible. The concept of Chemical-Specific Adjustment Factors (CS AFs) has been introduced to provide a method for the incorporation of quantitative data on interspecies differences or human variability in either toxicokinetics or toxicodynamics into the risk assessment procedure, by modifying the relevant default UF of 10. Incorporation of toxicokinetic or toxicodynamic data becomes possible if each factor of 10 is divided into appropriately weighted sub-factors as suggested by Renwick (1991, 1993) and adopted by WHO/IPCS (1994), see Section 5.2.1.3. 

The Community-Level Aquatic Systems Studies Interpretation Studies (CLASSIC) guidance document, which deals with the interpretation of results of microcosm and mesocosm tests in the risk assessment procedure of pesticides, recommends that regulatory model ecosystem experiments be conducted in spring to midsummer (Giddings et al. 2002). On the basis of the limited number of model ecosystem experiments described above, it seems that threshold concentrations for effects observed in early-season studies are reasonably predictive for threshold concentrations later in the season. Above these threshold concentrations, however, the intensity and duration of the responses (direct and indirect effects) may vary during different periods of the year. Consequently, the extrapolation of NOECcommunity values from one season to another seems to be possible with lower uncertainty than hazard estimates of higher concentrations in which both direct and indirect effects are involved. 

At the turn of the century, since 2000, the Korean Ministry of Environment started to introduce the risk assessment procedure in the process of revising water... 

Problem formulation. Within this process all available information about a contaminated site is collected including the nature of the contaminants and their sources, obvious effects and potential receptors as well as environmental recipients. Within this very first stage of the risk assessment procedure, an assessment endpoint has to be determined. Assessment endpoints are the expression of an environmental value (represented by an ecological entity) that is at risk, e.g. a distinct population that faces harm due to pollution. It has to be emphasised that toxicity-test endpoints or other measurement endpoints (in general, measured effects under test conditions) in most cases do not represent assessment endpoints (response of population or ecosystem in the field). Measurement endpoints should be representative for assessment endpoints or have a known relationship to the assessment endpoint allowing the extrapolation of data. 

In the following scheme an outline is given of the risk assessment procedure. (RIVM, VROM, VWS, 2002). 

Risk characterization is the final step in the risk assessment process. It comprises quantitative or semiquantitative estimations, including uncertainties, of the probability of adverse health effects in people associated with exposure to the toxic agents. Risk characterization is based on the information gathered through the first three steps in the risk assessment procedure. It is important that the weight of evidence leading to the conclusions be openly discussed. Risk characterization should include a description of the primary causes of uncertainties. 

While familiarisation with the area to be visited is important, an essential part of the risk assessment procedure, that is often overlooked, is familiarisation with the mode of transport to be used. If this is a self-drive minibus, prior to the journey, a check should be carried out on basic safety features such as tyres, lights, windscreen washers/wipers, brakes, availability of first aid kit and fire extinguisher, fluid levels, doors (operate freely and close securely) and warning instruments. Driver effectiveness and fatigue is also influenced by poor driving position and conditions so, before setting off the driver should adjust the seat, the mirrors and check that they can reach all the essential controls. 

The example of phenol release into river ecosystems clearly illustrates that the risk assessment procedures currently used are far from perfect. The major limitations concern the issues of... 

In recent years major developments in risk assessments of biocidal products have taken place within the European Union (EU) as a result of the implementation of the Biocidal Products Directive (BPD) 98/8/EC. This legislation will result in the highest level of testing substances and products of antimicrobial activity and will set the standard for product registration for all suppliers of biocides. Therefore, the risk assessment procedures described within the BPD technical notes for guidance will be discussed in the following sections and compared to other risk assessment procedures worldwide. 

The risk assessment procedure for human health is usually a quantitative assessment and the stages of the assessment follow those outlined in the introduction of this Chapter. For biocidal products, the risk assessment focuses on the health effects arising specifically from the product itself. However, the majority of the data and endpoints used in the assessment will have been conducted on the active substance(s), substances of concern or other constituents within the product formulation. 

In case the results are deemed insufficient or inconclusive, the risk assessment procedure - identification, analysis and evaluation - shonld be restarted. 

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