Maximum individual risk, defined

There me two major types of risk ina. imuin individual risk and population risk. Maximum risk is defined e.xacUy as it implies, Uiat is the ma.ximum risk to an individual person. Tliis person is considered to have a 70-year lifetime of exposure to a process or a chemical. Population risk is Uie risk to a population. It is expressed as a certain number of deaths per Uiousand or per million people. For example, a fatal annual risk of 2 x 10 refers to 2 deatlis per year for every million individuals. These risks are based on very conser ative assumptions, llich may yield too high a risk. 

Average Individual Risk— total population Allows risk to a constant population to be compared for several movements allows for the extent of consequence to figure more heavily in risk measure May be significantly misleading with regard to the maximum risk level if this risk is limited to a small portion of the defined oommunity... 

The scenario tolerable frequency associated to each consequence severity category indicates the frequency in which the organization tolerates an event with such impact. To provide an example, according to CCPS (2001), a maximum tolerable risk for workforce of 10 per year is a typical criteria used with LOPA, considering any one scenario affecting an individual (with potential to cause a fatality within a unit or local area). These values are used during LOPA to define how much risk reduction a scenario needs to achieve a tolerable frequency of occurrence. 

The individual risk (called location-based risk in the Netherlands) is defined as the risk to an (unprotected) individual at a specific location. The risk is expressed as the probabihly of fatality in one year as a direct result of an on-site incident involving hazardous substances. The individual risk is visualized by risk contours on a map. The risk for the location of vulnerable objects is limited to a maximum of 10 per year. Examples of vulneiable objects are dwellings, schools and hospitals. For less vulnerable objects, e.g. small offices, the individual risk contour of 10 per year is a target value. 

These cannot be accurately defined. But both patients and nonpatients justifiably expect some guidance, and doctors and government departments will wish to be helpful. They may reasonably advise as a safe or prudent maximum (there being no particular individual contraindication) men, not more than 21 units per week (and not more than 4 units in any one day), and women, 14 units per week (and not more than 3 units in any one day). Consistent drinking more than these amounts carries a progressive risk to health (see also Alcoholic drinks and mortality, below). In other societies recoirunended maxima are higher or lower. 

As the individual toxicity threshold of BAs has not been defined exactly, varying significantly between individuals, histamine levels above 500-1000 mg/kg must be considered of potential risk to human health (Taylor, 1985). In some European Countries tolerance levels for histamine in food and beverages have been defined. The maximum level of tolerance of histamine in wine has been established in Switzerland at lOmg/L, in France at 8mg/L, in Belgium at 5-6 mg/L, and in Germany at 2 mg/L, however the level for histamine-free wines should be lower than 0.5 mg/L (Bauza et al., 1995 Lehtonen, 1996). 

The UL is the maximum level of daily intake that is unlikely to pose risks of adverse health effects to most individuals in a given age/sex category. UL does not imply a possible health benefit from intakes at that level [30]. Although the EAR, RDA and UL are relatively straightforward recommendations that are in keeping with global use, the AI value, which is less rigorously defined, may have limited utility. New recommendations for vitamin A in the United States have not yet been defined. 

---