In fact, all discourses are necessary to manage this low-level risk. This coherence and differentiation of expertise around managing blood risk has practical consequences. As Hunt [54] notes, governance of risk is characterised by risk avoidance rather than risk management and is in turn dominated by a preoccupation with safety. The further corollary is the expanding panoply of regulation and guidelines. This may be noted in blood supply. And when 'something happens'-a threat to safety-the virtuous cycle of risk, regulation, and prescription is interrupted. The relentless pressure for the systemisation and integration of risk management practices continues as a watchword for corporate social responsibility (see [55] ). This virtuous cycle is reinforced by the use of a precautionary logic. As Haggerty [14] , notes, precaution emphasises the worst eventualities. It is not so much about risk. It "invites one to anticipate what one does not yet know, to take into account data, hypothesis and simple suspicions" [56:288] . With a product as vital and special as transfused blood, precaution is necessary. But societally it may feed anxieties and increase risk aversion. Practically, we point to consideration being given to enterprise risk management (ERM), recently developed as ISO 31000 (see [57] ) and accepted by the Canadian Standards Association in 2010.. ERM considers any risks or uncertainties affecting objectives, requires a flexible organization to tailor risk management, formalising monitoring review and consultation, and demands accountability from all those dealing with the risk. All senior managers must be committed to the process which must be used by all decision-makers in a flexible organizational structure. In its stages, it considers risk in careful ways. In setting the context and identifying risk, it suggests consideration of risk appetite and triggers. In analyzing and treating risk, ERM points towards acceptance, control and mitigation. It suggests ensuring that residual risk and its potential impacts are not ignored as it is not possible to remove all uncertainty. ISO 31000 may be complemented by using a safety-case approach which requires the incorporation of all evidence to ensure the system is safe to operate (see [58] , potentially modified to permit inputs from all appropriate stakeholders to organize heterogeneous information and concerns to ensure the safety and dependability of a larger network (i.e. the blood system).