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A B C D E F G H I J K L M N O P Q R S T U V W Z All terms


The combination of the frequency, or probability, of occurrence and the consequence of a specified hazardous event.
Note ? The concept of risk always has two elements: the frequency with which a hazardous event occurs and the consequences of the hazardous event.


  • IEC 60300-3-9

The chance of something adverse happening where 'something' refers to a particular consequence of the manifestation of a hazard. Risk reflects both the likelihod that harm will occur and its severity in relation to the number of people who might be affected, and the consequences to them.


  • HarsNet working group, 2002,  HarsBook, A technical guide for the assessment of highly reactive chemical systems, Frankfurt.

Risk should be expressed in the most suitable terms. Some of the commonly used outputs are:

a) predicted frequency of mortality or morbidity to an individual (individual risk);

b) frequency versus consequence plots (known as F-N curves where F stands for frequency and N the cumulative number of people suffering a specified level of harm or the cumulative cost of damage) for societal risk;

c) the statistically expected loss rate in terms of casualties, economic cost or environmental damage;

d) the distribution of the risk of a specific damage level, presented as a contour plot, displaying levels of equal damage.


  • IEC 60300-3-9

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