Highest acceptable risk

The highest acceptable risk (Ry) is a risk which is just acceptable. Usually, it can be specified only qualitatively. This is a discretionary decision and influenced by the respective plant and process conditions. 

An acceptance criterion defines the highest accepted risk, as documented for example in a company s SHE policy. The risk is expressed as a combination of the frequency of the occurrence of losses due to accidents per unit of exposure in a specified activity and the consequences of such losses. 

It was assumed that thresholds for carcinogenicity were either nonexistent or nonmeasurable. A multistage model was used in many cases with a data base similar to the Water Quality Criteria, and often calculated values were rounded off to the nearest digit. The guidelines state The model is designed to estimate the highest possible upper limit of incremental risk from a lifetime of exposure to a particular daily amount of substance.. . . An acceptable risk of 1 in 100,000 per lifetime was arbitrarily selected as the criterion. 

Maximum tolerated dose (MTD) The highest dose that produces an "acceptable" risk for toxicity or, expressed differently, the dose that, if exceeded, would put individuals at "unacceptable" risk for toxicity. 

Health Canada has recommended a maximum acceptable level of 350 /ag/L for trihalomethanes in drinking water. The U.S. EPA recommendation is 100 /xg/L. Risk estimates for exposure to trihalomethanes at this concentration based on 2 L of water per day for a 70-kg man is 1 in 2.5 million per year. Chloroform poses the highest cancer risk. 

Cost of cleanup is usually directly proportional to the cleanup standard. In practice, the cost of remediation is highest where human or environmental risk is greatest. Established industrial areas that will remain in that use category will have higher acceptable cleanup concentrations than will residential or commercial areas. 

The Medicines Act, together with the associated EU legislation and EU and ICH guidelines, should ensure that the safety of drugs made to the highest quality, the acceptability of their risk/benefit ratio and the promotion of correct information to the prescribers and consumers are the dominant features of the controls that operate today. 

Abstract Two thirds of the nearly half a million deaths per year in the United States due to sudden cardiac death (SCD) is attributed to coronary artery disease (CAD) and most commonly results from untreated ventricular tachyarrhythmias. Patients with ischemic cardiomyopathy and left ventricular dysfunction are at highest risk for SCD, but this still defines only a small subset of patients who will suffer SCD. Multiple lines of evidence now support the superiority of implantable cardioverter defibrillator (ICD) therapy over antiarrhythmic therapy for both primary and secondary prevention of SCD in advanced ischemic heart disease. Optimization of ICD therapy in advanced ischemic cardiomyopathy includes preventing right ventricular pacing as well as the use of highly effective anti-tachycardia pacing to reduce the number of shocks. While expensive, ICD therapy has been shown to compare favorably to the accepted standard of hemodialysis in cost effectiveness analyses. 

Traditionally, when setting acceptable (typically considered safe ) levels of exposure, the risk assessor will select the highest experimental exposure that does not cause an adverse effect (no-observed-adverse-effect level (NOAEL)) in an experiment that demonstrated a graded exposure response from no effect to adverse effects. In standard risk-assessment practice (NRC 1993a), the exposure level identified as the NOAEL would then be divided by appropriate uncertainty factors and modifying factors to derive an acceptable exposure level for humans. However, there are a number of limitations in this... 

This test is perceived as useful in the risk estimation process, to identify specific agents, or classes of agents, for which acceptable exposures in the adult may not be acceptable to the developing organism, to elucidate long-term consequences of pre- and perinatal exposures and results, to determine the relationship of lowest effective (or highest no effect) dose for behavioral effects versus the dose for overt or general toxicity effects, and to identify, for human exposures, those effects which may be important to monitor. 

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