240 ◾ Risk Assessment and Security
6.4.5 Conversion of a Risk Reference to a Risk Referent
e conversion of a risk reference to a risk referent requires three factors:
1. Establish the appropriate risk proportionality factor, that is, the fraction of
existing societal risk, also known as risk reference, which would be considered
acceptable in a condition where there was a very favorable indirect benet–cost
balance, for both regulated voluntary (or voluntary) and involuntary risks (F1).
2. Establish a factor which is the risk proportionality derating factor, which can
be applied in those conditions where the indirect benet–cost balance is not
as favorable, and which transforms the risk proportionality factor in those
identied conditions ...