This book examines the relationship between politics, ethics and law in risk governance involving multi-valued human biological materials, such as blood. HIV blood contamination episodes in the USA, England and France are used to examine the emergence of and the consequences resulting from the politicization of risk. The emergence of the phenomenon is examined through a focus on the role of the gift relationship in blood donation, as well as scientific expertise and innovation in risk governance processes involving the blood system. Its consequences are examined through an analysis of legal action taken by aggrieved patient groups, in addition to a critique of the increased use of precautionary and regulatory strategies in dealing with emerging risks to blood safety.