Elements of the blood management system have been drawn to ISO 31000. Furthermore, processes such as recording, inter-professional communication, notification and disclosure have been applied in dealing with blood risk. Risk triggers and residual risk point to the relevance of hazard and liability discourses, especially as in other domains, use of the precautionary principle has been shown to trigger concerns and lower trust in governance structures (see [59] ). So for the institution of precaution we must be clear on what we are managing, why and in what ways. For the Canadian blood system, a new procedure of providing reasons for recall will assist hospitals and other donation agents in managing perceived risks. Yet the role of expert biases and domain interests are likely to continue to exist, and must be understood and incorporated to ensure blood safety and continued public trust and to provide timely responsiveness in such a high reliability system. We suggest the framework of ISO 31000 emphasising context, risk identification and assessment, risk treatment, communications and consultation is useful, along with a safety-case approach. Communication about ways to protect public safety is always necessary and this must include clarity on definitions, responsibilities, and public perceptions and what the consequences of even minor errors mean in a complex system. Furthermore, error as a risk state needs careful theorizing and application in systematic risk management approaches.